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The oxidation of 2-butenes Tse, Ronald Siu-Man 1966

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THE OXIDATION OF 2-BUTENES  by  RONALD SIU-MAN TSE B . A . S c , U n i v e r s i t y of Toronto, 1958 M.Sc, U n i v e r s i t y of B r i t i s h Columbia, 1962.  A THESIS SUBMITTED IN PARTIAL FULFILMENT OF THE  REQUIREMENTS FOR THE DEGREE OF DOCTOR OF PHILOSOPHY i n t h e Department of Chemistry  We accept t h i s t h e s i s as conforming t o t h e r e q u i r e d standard  THE UNIVERSITY OF BRITISH COLUMBIA June, 1966.  In p r e s e n t i n g t h i s t h e s i s  i n p a r t i a l f u l f i l m e n t o f the  requirements  f o r an advanced degree a t the U n i v e r s i t y o f B r i t i s h Columbia,, I  agree  t h a t the L i b r a r y s h a l l make i t f r e e l y a v a i l a b l e f o r r e f e r e n c e and study,  I f u r t h e r agree  t h a t permission., f o r e x t e n s i v e c o p y i n g o f t h i s  t h e s i s f o r s c h o l a r l y purposes  may  be g r a n t e d by the Head o f  Department o r by h i s representatives„  I t i s understood  my  that  or p u b l i c a t i o n o f t h i s t h e s i s f o r f i n a n c i a l g a i n s h a l l not be w i t h o u t my w r i t t e n  permission.  The U n i v e r s i t y o f B r i t i s h Vancouver 8, Canada  Columbia  copying allowed  The U n i v e r s i t y  of B r i t i s h  Columbia  FACULTY OF GRADUATE STUDIES  PROGRAMME OF THE FINAL ORAL EXAMINATION FOR THE DEGREE OF DOCTOR. OF PHILOSOPHY  of  RONALD SIU-MAN TSE  B . A . S c , U n i v e r s i t y of Toronto, 1958 M . S c , The U n i v e r s i t y  of B r i t i s h Columbia,  1962  MONDAY, JULY 18th, 1966, AT 11:00 A.M. ROOM 261, CHEMISTRY BUILDING  COMMITTEE I.N C HA RISE Chairman: W. R. C u l l en F. W. Dalby D. C. F r o s t  F. A, Kaempffer  "  !  C . A„ McDowell R. E„ P i n c o c k R. Stewart  E x t e r n a l Examiner: C. F. H, T i p p e r Department of I n o r g a n i c , P h y s i c a l and I n d u s t r i a l Chemistry The University of L i v e r p o o l L i v e r p o o l , England Research S u p e r v i s o r :  C. .A. McDowell  THE  OXIDATION OF 2-BUTENES ABSTRACT  In the f i r s t p a r t of t h i s work, the r e a c t i o n between c i s - and trans-2-butenes and oxygen atoms was s t u d i e d at room temperature i n a flow r e a c t o r i n the e s s e n t i a l absence of m o l e c u l a r oxygen. R e a c t i o n p r o d u c t s were found to c o n s i s t of hydrocarbons and oxygenated p r o d u c t s i n the r a t i o of approximately 2:1. The hydrocarbon p r o d u c t s were mainly ethane, some e t h y l e n e , a l i t t l e propane and isobutane, and t r a c e amounts of methane, n-butane and i s o b u t e n e . The oxygenated products were mainly a c e t a l d e hyde and p r o p a n a l , some c i s - and trans2,3-butene oxides, acetone, i s o b u t a n a l , butanone-2 and t r a c e s of o t h e r products. Peroxides were a l s o d e t e c t e d . C i s - t r a n s i s o m e r i s a t i o n was found t o occur d u r i n g the c o u r s e of the o x i d a t i o n r e a c t i o n . The d i s a p p e a r a n c e of the oxygen atoms c o u l d not be accounted f o r by the amount of oxygenated products nor by the d i s a p p e a r a n c e of the 2-butene. The r e a c t i o n order f o r the r a t e of prod u c t i o n of the v a r i o u s products and f o r the r a t e of d i s appearance of the 2-butene was found not t o be simply u n i t y w i t h r e s p e c t t o each of the r e a c t a n t s 2-butene and oxygen atoms. The f o r m a t i o n of products i s e x p l a i n e d i n terms of an i n i t i a l oxygen atom a t t a c k at the 2-butene t o form a b i r a d i c a l which i s thought t o decompose i n one of t h r e e ways; \-\-~{.\ • Other products are formed through the 0'  i n t e r a c t i o n of the r a d i c a l s thus produced, and from the r e a c t i o n s between these r a d i c a l s and the parent 2-butene. Ring c l o s u r e occurs t o produce expoxides. The disappearance of oxygen atoms i s e x p l a i n e d through an o l e f i n - c a t a l y s e d r e c o m b i n a t i o n of oxygen atoms v i a a complex ( TT or charge t r a n s f e r ) f o r m a t i o n between 2-butene and the oxygen atom or by way of a 4 - c e n t r e r e a c t i o n scheme i n v o l v i n g the b i r a d i c a l . The f o r m a t i o n of p e r o x i d e s i s thought t o be due t o the r e a c t i o n between the r a d i c a l s p r e s e n t and m o l e c u l a r oxygen thus produced. In the second p a r t of t h i s work, t h e thermal o x i d a t i c of c i s - and trans-2-butenes by m o l e c u l a r oxygen was i n v e s t i g a t e d i n a c o n v e n t i o n a l s t a t i c system.. P r e s s u r e time s t u d i e s were made at 289 C and at a t o t a l p r e s s u r e of 51 mm Hg. Cool flames were observed at the end of an i n d u c t i o n p e r i o d under c e r t a i n m i x t u r e r a t i o s . The  r e l a t i o n s h i p between the o v e r a l l p r e s s u r e i n c r e a s e and the i n i t i a l p r e s s u r e of 2-butene a t a t o t a l i n i t i a l p r e s s u r e was determined. The i n d u c t i o n p e r i o d at 289°C and a t a t o t a l p r e s s u r e of 51 mm Hg was determined i n r e l a t i o n t o the i n i t i a l 2-butene pressure„ Products formed d u r i n g . t h e i n d u c t i o n p e r i o d were mainly a c e t a l d ehyde, some p r o p a n a l , i s o b u t a n a l and butanone-2. A f t e r the end o f the i n d u c t i o n p e r i o d , l a r g e q u a n t i t i e s of hydrocarbons and other p r o d u c t s such as formaldehyde, methanol and carbon d i o x i d e appeared. K i n e t i c s t u d i e s d u r i n g t h e i n d u c t i o n p e r i o d were made a t t o t a l p r e s s u r e of 10-75 mm Hg, I t was found that d(Acet,aldehyde) •• . ^vh \ 2  ———r-  —  J  /  (0„ )  = k (2-Butene)  dt  Z.  a  = k (2-Butene)^(0 ) p  d(Isobutanal) —* — ' dt  2  2  , T, * 2 = k. (2-Butene) ( 0 ; .  , .  s  / n  o  l  2.  The v a l u e of k was determined over s i x temperatures each f o r c i s - and trans-2-butenes i n the range of 289357 C. There was no a p p r e c i a b l e d i f f e r e n c e i n k between u s i n g c i s - and trans-2-butenes as r e a c t a n t . I t was found t h a t 27.3+0.6 -(52700+1500)/RT .4 . -4 -1 k = 10 e 1. mole sec a Thermal i s o m e r i s a t i o n of 2-butenes t o isobutene,and the c a t a l y s e d c i s - t r a n s i s o m e r i s a t i o n of 2-butenes have a l s o been observed, '-•,.„''• A mechanism has been proposed t o e x p l a i n the observations. a  a  in  GRADUATE STUDIES Field  of Study:  Physical  Physics  B. A. D u n e l l W. C. L i n C. A. McDowell  Molecular  A„ Bree K. B. Harvey L. W. Reeves  T o p i c s i n Chemical  Spectroscopy and Structure  Chemistry  S t a t i s t i c a l Mechanics  R„ F.  Snider  Related Studies: I n o r g a n i c R e a c t i o n Mechanisms Organic  R e a c t i o n Mechanisms  J.  Halpern  R. E.  Pincock  ii S u p e r v i s o r : P r o f e s s o r C. A. McDowell  ABSTRACT In cis-  the f i r s t  and trans-2-butenes and oxygen atoms was  temperature  graphy.  s t u d i e d at room  i n a flow r e a c t o r i n the e s s e n t i a l absence  molecular oxygen.  of  Products were mainly analysed by gas chromato-  These r e a c t i o n products were found t o c o n s i s t of  hydrocarbons 2:1.  part of t h i s work, the r e a c t i o n between  and oxygenated  products i n the r a t i o of approximately  The hydrocarbon products were mainly ethane, s,ome e t h y l e n e ,  a l i t t l e propane and isobutane, and t r a c e amounts of methane, n-butane and isobutene.  The oxygenated  products were mainly  acetaldehyde and propanal, some c i s - and trans-2,3-butene  oxide,  acetone, i s o b u t a n a l , butanone-2 and t r a c e s of other p r o d u c t s . P e r o x i d e s were a l s o d e t e c t e d . C i s - t r a n s i s o m e r i s a t i o n , p r e v i o u s l y unobserved workers,  was  reaction.  by other  found t o occur d u r i n g the course of the o x i d a t i o n  The disappearance of the oxygen atoms c o u l d not be  accounted f o r by the amount of oxygenated  products nor by the  disappearance of the 2-butene, as observed by s e v e r a l p r e v i o u s authors.  The r e a c t i o n order f o r the r a t e of p r o d u c t i o n of the  v a r i o u s products and f o r the r a t e of disappearance of the 2butene was  found not t o be simply u n i t y with r e s p e c t t o each df  the r e a c t a n t s 2-butene and oxygen atoms. The f o r m a t i o n of products i s e x p l a i n e d i n terms of an initial  oxygen atom a t t a c k at the 2-butene t o form a b i r a d i c a l  o  +  W o*  iii which i s thought t o decompose i n one of t h r e e ways: CH3CHCHO + C H  3  0 CH3CH: + CH3CHO o  *~ \=S  + 0  v..  Other products are formed through the i n t e r a c t i o n of t h e r a d i c a l s thus produced,  and from the r e a c t i o n s  the parent 2-butene. Cis-trans  Ring  closure  isomerisation  between these r a d i c a l s and  occurs t o produce  epoxides.  i s e f f e c t e d by r o t a t i o n  the c e n t r e C-C bond i n t h e b i r a d i c a l and subsequent  about  s c i s s i o n of  the C-0 bond. The disappearance of oxygen atoms i s e x p l a i n e d through an o l e f i n - c a t a l y s e d  recombination of oxygen atoms v i a a complex  ( T T or charge t r a n s f e r )  f o r m a t i o n between 2-butene and the oxygen  at om 0 + 0 +  \=/ 0  \=/  (complex)  O2 + \=/  0 or by way of a 4-centre r e a c t i o n 0 +  \—^ 0  scheme i n v o l v i n g the b i r a d i c a l \  /  \  /  + o . 2  b—6  The f o r m a t i o n o f peroxides i s thought  t o be due t o t h e r e a c t i o n  between the r a d i c a l s present and molecular oxygen thus  produced.  iv the second p a r t o f t t h i s work, the thermal o x i d a t i o n  In  of. c i s - and trans-2-butenes  by molecular oxygen was  in  a c o n v e n t i o n a l s t a t i c system.  at  289°C and at a t o t a l i n i t i a l p r e s s u r e of 51 mm  were observed  investigated  P r e s s u r e - t i m e s t u d i e s were made Hg.  Cool  at the end of an i n d u c t i o n p e r i o d when the  (p0 /P2-butene)  w  a  o  s  ratio  g r e a t e r than u n i t y but not very l a r g e .  t h i s r a t i o becameovery l a r g e , no c o o l flame was  flames  When  observed but  the  pressure-time curve todk on a simple S - s h a p e W h e n t h i s : r a t i o became l e s s than u n i t y , no p r e s s u r e i n c r e a s e was  d e t e c t e d at the  end of the i n d u c t i o n p e r i o d . The r e l a t i o n s h i p between the o v e r a l l p r e s s u r e i n c r e a s e "and the i n i t i a l p r e s s u r e of 2-butene at a t o t a l i n i t i a l of  51 mm  Hg was A P /  where  AP  initial  51 mm  found t o be  P2-butene =  1  6  ~ 6.0xl0  6  P _butene  - 2  2  i s the o v e r a l l p r e s s u r e i n c r e a s e and P2-butene  *  n e  2-butene p r e s s u r e . The  of  pressure  induction period T  Hg was  at 289°C and at a t o t a l p r e s s u r e  found t o r e l a t e t o the i n i t i a l  2-butene p r e s s u r e  by the f o l l o w i n g e x p r e s s i o n  T -  7  '  5 5 x l  °  *8  3 2  (P2-butene^ where T i s i n minutes and P2-butene 2-butene i n mm  of  i s  t  h  e  i  n  i  t  i  a  l  p r e s s u r e of  Hg.  Products formed d u r i n g the i n d u c t i o n p e r i o d were mainly' acetaldehyde,  some propanal, i s o b u t a n a l and butanone-2.  the end of the i n d u c t i o n p e r i o d , l a r g e q u a n t i t i e s of and other products such as formaldehyde,  methanol and  After  hydrocarbons carbon  V  d i o x i d e appeared.  Methane and<rcarbon monoxide appeared  i n large  amounts immediately a f t e r t h e end of t h e i n d u c t i o n p e r i o d but i t appeared they were subsequently consumed.  The maximum i n the  methane c o n c e n t r a t i o n o c c u r r e d l a t e r than t h a t observed f o r t h e carbon monoxide c o n c e n t r a t i o n .  Crotonaldehyde was not d e t e c t e d .  K i n e t i c s t u d i e s were made at t o t a l p r e s s u r e of 10-75 mm Hg.  I t was found t h a t d(Acetaldehyde) dt d(Propanal) dt  _butene) (Oo) 3  =  k  ( 2  2  a  -butene) *(0 ) * 3  =  d(lsobutanal) dt  =  k  P  k  ( 2 1  ( 2  2  2  _  tene) (0 ) 2  b u  7  9 2  The value of k„ was determined over s i x temperatures  each f o r  c i s - and trans-2-butenes i n t h e range o f 289-357°C.  There was  no a p p r e c i a b l e d i f f e r e n c e i n k butenes  as r e a c t a n t . V  =  10  a  between u s i n g c i s - and t r a n s - 2 -  I t was found t h a t Ac^^sec" .  2 7 . 3 0 . 6 -(52700 1500)/RT ±  e  1  ±  BL  Thermal  i s o m e r i s a t i o n of 2-buten€6to isobutene and  the c a t a l y s e d c i s - t r a n s i s o m e r i s a t i o n of 2-butenes have a l s o been observed. A mechanism has been proposed t o e x p l a i n the observatA ions i n v o l v i n g t h e i n i t i a l  a b s t r a c t i o n of hydrogen  from t h e  2-butene by oxygen t o form a b u t e n y l r a d i c a l and a HO2 r a d i c a l : CH CH=CHCH 3  3  + 0  2  >• CH CH=CHCH 3  .I  (R) + H 0  2  2  CH CH-CH=CH (R) 3  2  The b u t e n y l r a d i c a l i s thought t o r e a c t r a p i d l y w i t h oxygen t o  form a peroxy  radical  CH CH-CH=CH 3  2  0  +  *~  2  CH CH-CH=CH 3  (A)  2  0-0' CH CH=CHCH 3  2  0  +  2  —»~  CH CH=CHCH 00"  (B)  2  3  Acetaldehyde i s probably produced through the i s o m e r i s a t i o n subsequent  decomposition of the A-butenyl peroxy CH -CH-CH=CH 3  2  CH CH-CH-CH  (A)  3  0-0'  and  radical  2  0—0  CH -CH|CH-CH 3  -—>•  2  CH CH0  CH CH0  +  3  2  I 1 I  O-J-O  The B-butenyl r a d i c a l i s l i k e l y t o undergo i s o n e r i s a t i o n t o the A-form. CHo-CH=CH-CH 3 j 2  9  CHc,CH-CH-CH 3 ^ 2  (B)  v  6—0 CH CH-CH-CH 3  9  /  0-0 2  —  CH -CH-CH=CH 3  \)-0^  2  (A)  0-0'  Other products are probably formed through the i n t e r a c t i o n of r a d i c a l s produced  and through the r e a c t i o n  between these r a d i c a l s  and the parent 2-butene and oxygen. T h i s mechanism must be incomplete s i n c e thus d e r i v e d , employing the s t a t i o n e r y disagreement  law  s t a t e treatment, i s i n  with the observed e x p r e s s i o n .  mechanism which would give the observed r a t e found.  the r a t e  A satisfactory law has not been  vii: CONTENTS CHAPTER I.  General I n t r o d u c t i o n  CHAPTER I I  THE REACTION BETWEEN 2-BUTENES AND ATOMIC OXYGEN 1. I n t r o d u c t i o n  14  Experimental D e t a i l s (TJ Apparatus a. Flow r e a c t o r b. N i t r o g e n metering system c. N i t r i c oxide metering system d. 2-Butenes metering system  25 25 25 27 27  ( i i ) Gas chromatography system  28  (iii)  (iv)  Material a. 2-Butenes b. N i t r o g e n c. N i t r i c oxide d. Helium, e. Other Analysis a. I d e n t i f i c a t i o n b. Q u a n t i t a t i v e measurement c. Peroxide a n a l y s i s  (v) Procedure (vi) C a l c u l a t i o n s 3  PAGE T  Experimental  Results  33 35 35 35 35 35 36 41 42 43 44  51 Discussion CHAPTER I I I . THE OXIDATION OF 2-BUTENES BY MOLECULAR OXYGEN 65 1. I n t r o d u c t i o n 4  Experimental D e t a i l s CO Apparatus (ii) Material ( i i i ) Analysis ( i v ) Procedure a. Pressure-time s t u d i e s b. K i n e t i c s t u d i e s Experimental R e s u l t s ( I ) .'Pressure-time s t u d i e s a. P Q > P2-butene 2  b. P 0 < P2-butene c. A p d. Induction p e r i o d 2  78 81 82 82 83 83 84 84 84 88  viii (il)  (iii)  Products a. During and a f t e r the i n d u c t i o n period b. I d e n t i f i c a t i o n Kinetic studies a. P r o d u c t i o n d u r i n g the i n d u c t i o n period b T h e : r e l a t i o n s h i p between i n i t i a l r a t e s and (Po /P2~butene) constant t o t a l p r e s s u r e Reaction order A c t i v a t i o n energy and frequency factor 2-Eutenes i s o m e r i s a t i o n t o isobutene Cis-trans isomerisation  91 96  97  a t  2  4. D i s c u s s i o n ( i ) General ( i i ) Mechanism of the o x i d a t i o n of 2-butenes d u r i n g the i n d u c t i o n period  97 102 106 107 109 111 119 132  REFERENCES APPENDICES I , II . Ill , IV, V, VI,  VII,  VIII,  IX,  R e s u l t s of the r e a c t i o n between 0-atoms and cis-2-Butene: 137 Dependence on (O)± f o r the r e a c t i o n between 0-atoms and cis-2-Butene 145 Dependence on ( c i s - 2 - b u t e n e ) ^ f o r the r e a c t i o n between 0-atoms and cis-2-Butene 147.< R e s u l t s of t h e r e a c t i o n between 0-atoms and trans-2-Butener: 149 Dependence on ( 0 ) ^ f o r the r e a c t i o n between 0 - a t o m s and trans-2-Butene 155 Dependence on (trans-2-Butene)^ f o r the r e a c t i o n between 0-atoms and t r a n s - 2 158 Butene R e s u l t s of Pressure-time S t u d i e s f o r the O x i d a t i o n of 2-Butenes by Molecular Oxygen at 289°C 160 R e s u l t s of K i n e t i c S t u d i e s f o r the O x i d a t i o n of 2-Buter.es by Molecular Oxygen at 289°C 163 Determination of the a c t i v a t i o n energy of t h e o x i d a t i o n of 2-butenes by molecular . 17a oxygen, 289-357°C" ""': r^^--  ix LIST OF TABLES PAGE 1.~  E l u t i o n time c a l i b r a t i o n s f o r the Column J .  Perkin-Elmer 31  2.  E l u t i o n time c a l i b r a t i o n s f o r the HMPA Column  31  3.  E l u t i o n times and r e l a t i v e s e n s i t i v i t i e s f o r the DNP Column  32  4.  E l u t i o n time c a l i b r a t i o n s f o r the F & M.Column  33  5.  T y p i c a l experimental c o n d i t i o n s and r e s u l t s  44  6.  A n a l y s i s of the hydrocarbon  45  7.  Order  of r e a c t i o n w i t h r e s p e c t t o 2-butene  46  8.  Order  of r e a c t i o n w i t h r e s p e c t t o oxygen atoms  47  9.  Thermodynamic data f o r the c a l c u l a t i o n of K43 44  52  10.  O x i d a t i o n products obtained by B r i l l  71  11.  R e s u l t s of experiments  12.  Hydroperoxides  13.  A n a l y s i s of geometric isomers of the B o b t a i n e d by Chauvel et a l  14.  Rate c o n s t a n t s o b t a i n e d by ChauVel et a l  77  15.  Volumes of v a r i o u s p a r t s of the apparatus  81  16.  A n a l y s i s of r e a c t i o n products by Molecular 5A Column  Sieves  17.  Reaction orders f o r acetaldehyde, isobutanal production  and  18.  E  19.  Thermal i s o m e r i s a t i o n of cis-2-butene t o isobutene  109  20.  Cis-2-butene isobutene  110  21.  Comparison of the A P  22. 23.  a  f r a c t i o n of products  by Chauvel  and Barone  et a l  73  o b t a i n e d b y C h a u v e l et a l  73  hydroperoxide  propanal  95  and A v a l u e s f o r c i s - and trans-2-butene  i s o m e r i s a t i o n t o trans-2-butene  75  106 107  and  v a l u e s i n the present work  with those g i v e n by B l u n d e l l and Skirrow  111  Comparison of c o n d i t i o n s when AP —*. 0 C a l c u l a t e d acetaldehyde p r e s s u r e at s e v e r a l T values  113 114  X  LIST OF KIGURES 1.  Schematic diagram of t h e v a r i a t i o n o f o v e r a l l r a t e of hydrocarbon o x i d a t i o n w i t h time  2.  T y p i c a l temperature-pressure r e l a t i o n s h i p at constant onixture r a t i o i n hydrocarbon o x i d a t i o n  PAGE 1 2  3.  A r r h e n i u s p l o t of 1/T f o r propane o x i d a t i o n  3  4.  Hypothetical temperature  9  5.  E f f e c t of p r e s s u r e on the y i e l d per oxygen atom  21  6.  Flow r e a c t o r system  26  7.  N i t r o g e n metering system  8.  Gas chromatography system  29  9.  E l u t i o n time c a l i b r a t i o n s on the DNP Column  34  10.  A n a l y s i s of r e a c t i o n products on Column J  37  11.  A n a l y s i s of r e a c t i o n products on the HMPA Column  38  12.  A n a l y s i s of r e a c t i o n products on the DNP Column  39  13.  A n a l y s i s of r e a c t i o n products on the F & M Column  40  14.  T o t a l and oxygenated  products from c i s - 2 - b u t e n e  49  15.  T o t a l and oxygenated  products from trans-2-butene  50  16.  P r o g r e s s of r e a c t i o n at 289°C and at 385°C o b t a i n e d by B l u n d e l l and Skirrow  heat e v o l u t i o n and heat l o s s  against  "  27  67  17.  R e l a t i o n s h i p between oxygen .absorbed and hydroperoxide produced i n 1-butene o x i d a t i o n by Chauvel et a l 74  18.  R e l a t i o n s h i p between oxygen absorbed and hydroperoxide produced i n 2-butene o x i d a t i o n by Chauvel et a l 74  19.  Apparatus f o r the study of the thermal o x i d a t i o n of 2-butenes by molecular oxygen  79  20.  C a l i b r a t i o n of the s p i r a l gauge  80  21.  Pressure-time study, c o o l flame r e g i o n  85  22.  P r e s s u r e - t i m e study, slow combustion  86  23.  R e l a t i o n s h i p between t o t a l p r e s s u r e i n c r e a s e and i n i t i a l 2-butene p r e s s u r e  region  87  xi: PAGE 24. ~ 257  R e l a t i o n s h i p between i n d u c t i o n p e r i o d and i n i t i a l trans-2-butene p r e s s u r e  89  2 R e l a t i o n s h i p between 1/(P2-butene)  a  n  d  ^"  90  26.  A n a l y s i s of r e a c t i o n products on the DNP Column  92  27.  A n a l y s i s of r e a c t i o n products on t h e HMPA Column  93  28.  A n a l y s i s of carbon d i o x i d e on the HMPA Column  94  29.  P r o d u c t i o n of acetaldehyde, n-butanal and butanone-2  98  30.  Three t r e n d s of acetaldehyde  31.  Acetaldehyde  32.  R e l a t i o n s h i p between l o g R^ , l o g 0 and log  33.  (PO ^PBU^  propanal, i s o b u t a n a l , production  99  p r o d u c t i o n at low p r e s s u r e s  F  O  R  A  2  C  E  T  A  L  D  E  "  V  D  100  E  1  R e l a t i o n s h i p between l o g R , l o g 0 and l o g (po«/ 2-butene^ * P o p a n a l ana i s o b u t a n a l  0  1  i  p  O R  r  34. c Determination of r e a c t i o n order with r e s p e c t t o 2-butene f o r acetaldehyde p r o d u c t i o n  103 104  35.  D e t e r m i n a t i o n o f r e a c t i o n order w i t h r e s p e c t t o oxygen f o r acetaldehyde and p r o p a n a l p r o d u c t i o n  105  36.  Determination o f a c t i v a t i o n energy and frequency f a c t o r f o r acetaldehyde p r o d u c t i o n  108  37.  C a l c u l a t e d acetaldehyde p r e s s u r e at s e v e r a l values  115  T  xii  ACKNOWLEDGEMENT, ; ,.. r The Professor  author wishes t o express h i s g r a t i t u d e t o  C. A. McDowell f o r h i s l a s t i n g i n t e r e s t ,  and e n l i g h t e n i n g d i s c u s s i o n s throughout  supervision  the course of t h i s  work. The author i s a l s o g r a t e f u l t o Dr. E. A. O g r y z l o f o r h i s h e l p f u l suggestions d u r i n g the f i r s t The Columbia  part of t h e work.  author wishes t o thank the U n i v e r s i t y of B r i t i s h  f o r Teaching A s s i s t a n t s h i p s during t h e p e r i o d 1962-  66 and f o r Research A s s i s t a n t s h i p s f o r the p e r i o d The  1964-66.  author a l s o wishes t o thank the g l a s s - b l o w i n g ,  mechanical and e l e c t r o n i c workshop s t a f f s f o r t h e i r i n t h e c o n s t r u c t i o n of p a r t s of t h e apparatus.  assistance  CHAPTER I  r  GENERAL INTRODUCTION The  o x i d a t i o n of hydrocarbons has been under  i n v e s t i g a t i o n f o r the past 60 years\  intense  A number of e x c e l l e n t  1-4 reviews have been w r i t t e n o x i d a t i o n i s w e l l known but  The  c h a r a c t e r i s t i c s of  i t s mechanism i s f a r from  this being  elucidated. The  hydrocarbon (and many other o r g a n i c compounds)  o x i d a t i o n u s u a l l y begins with an i n d u c t i o n p e r i o d , d u r i n g which the o v e r a l l r a t e of o x i d a t i o n i s very slow and only a very p o r t i o n of the r e a c t a n t s i s consumed.  At the end of the  i n d u c t i o n p e r i o d , the o v e r a l l r a t e suddenly i n c r e a s e s  dramatical  l y u n t i l a c e r t a i n maximum value, then e i t h e r decreases a or simply  levels off.  represented  little  T h i s sequence of events i s s c h e m a t i c a l l y  i n F i g . 1.  c o  F i g . 1.  small  Schematic diagram of the v a r i a t i o n of o v e r a l l r a t e of hydrocarbon o x i d a t i o n w i t h time.  2  The sudden i n c r e a s e i n o v e r a l l r a t e of o x i d a t i o n i s sometimes accompanied  by the appearance of c o o l flames under  mixture, p r e s s u r e and temperature c o n d i t i o n s .  certain  Fig.  2 schematic-  a l l y shows a t y p i c a l r e l a t i o n s h i p of these e x p e r i m e n t a l c o n d i t ions. for  In the c o o l flames r e g i o n , t h e r e are u s u a l l y  sub-zones  1-5 c o o l flames. Another c h a r a c t e r i s t i c of the slow o x i d a t i o n of hydro-  carbons i s the common e x i s t e n c e of a temperature range, u s u a l l y ~350-400°C,  i n which the temperature c o e f f i c i e n t  rate i s negative. shown i n F i g . 3.  of o v e r a l l 5  A t y p i c a l example i s the o x i d a t i o n o f propane , V a r i o u s e x p l a n a t i o n s have been suggested t o  account f o r the n e g a t i v e temperature c o e f f i c i e n t  1  0  6 7 ' .  i  4oo  8oo  mm  H9  Pressure F i g . 2.  T y p i c a l temperature-pressure r e l a t i o n s h i p at constant mixture r a t i o i n hydrocarbon o x i d a t i o n .  3 The products of the slow and c o o l flame o x i d a t i o n of hydrocarbons i n c l u d e carbon monoxide, carbon d i o x i d e , aldehydes, ketones, a c i d s and water.  At low temperatures  peroxides are u s u a l l y o b t a i n e d .  (~ 200°C), hydro-  At h i g h temperatures  (~400  C) ,  c r a c k i n g products such as o l e f i n s , p a r a f f i n s and hydrogen are :': found**. The c h a r a c t e r i s t i c s of the slow and c o o l flame o x i d a t i o n of hydrocarbons i s t y p i c a l of branched-chain r e a c t i o n s . However, the long i n d u c t i o n p e r i o d and the subsequent  slow  a c c e l e r a t i o n i n d i c a t e that the c h a i n b r a n c h i n g i s not due t o the r e a c t i o n of r a d i c a l s w i t h the parent r e a c t a n t molecules. Semenov' ^ has proposed a t h e o r y of degenerate c h a i n b r a n c h i n g L  400  I  1  1-5  350  1-6  "C  300  n  1  1-7  IOVT-K  F i g . 3.  A r r h e n i u s p l o t of 1/r f o r propane oxidation**.  4 that has been widely accepted.  H i s main assumption  i s t h a t the  c h a i n b r a n c h i n g encountered i n slow and c o o l flame o x i d a t i o n of o r g a n i c compounds i s due t o the r e a c t i o n of a r e l a t i v e l y i n t e r m e d i a t e product, X, which i s formed by a chain process.  non-branching  T h i s type of b r a n c h i n g i s g e n e r a l l y  degenerate branching. RH + o 2  called  T h i s scheme can be r e p r e s e n t e d as f o l l o w s : k x .-r  ^—*-  —  stable  K  i n e r t products M  2 ^ w radicals  (1)  (branching)  (2).  It can be shown, from the c o n s i d e r a t i o n of the r a t e s of f o r m a t i o n and disappearance of X, that [X]  =  ° K (i> - l ) - k 2  0  where n  e  (3)  z  x  = l e n g t h of the primary c h a i n , independent  of time;  = number of primary c h a i n s per u n i t time generated  Q  by a primary i n i t i a t i o n t  reaction;  = time.  The r a t e of f o r m a t i o n of i n e r t products i s given by  M'*». dt  i L  [k (*> - D - k J f i i : . 2  (4)  k ( \) -1) - k i  J  2  If the p r e s s u r e i n c r e a s e , ^ P,  i s a measure of the p r o g r e s s  of the r e a c t i o n , d^P dt  r  Integration gives r  k.tfn A  p  =  ± [k„(U Z  2 e -l)-k ]2.(  [k (U 2  -D-kJt -[k (U 2  -D-kJt-l  1  J  (5)  5 Under u s u a l experimental c o n d i t i o n s , t i s very l a r g e when P i s measureable.  The e x p o n e n t i a l term i n s i d e the'.brackets i s  much l a r g e r than the other terms.  [k (  k i v no  -  A P  Therefore,  -D-kJt  2  o -D-k^  [k ( 2  B 2  0  ; ; (6)  T  E  0  Thus t h i s theory p r e d i c t s t h e e x p o n e n t i a l i n c r e a s e i n AP w i t h time  at l e a s t d  The  after the induction period.  AP  B  dt  0  0*  Moreover,  ' .  e  0  (7)  AP  r a t e of a c c e l e r a t i o n  =  d/°  kx dCx}  dt Thus at  dt  P  ,  I  m  a  x  d  P  = 0  t  a  n  d  Cx]  d  v/  = o  —  U .  T h i s means t h a t the c o n c e n t r a t i o n of the substance  responsible  f o r degenerate branching r i s e s t o a maximum when the o v e r a l l r a t e of r e a c t i o n i s at a maximum. The (350-400°C) methane  -. -•  branching  agent i n t h e " h i g h  temperature"  o x i d a t i o n s o f a number o f compounds, f o r example,  , ethylene  jo  '  13  , cyclopropane  been shown t o be formaldehyde.  14  and methanol  Acetaldehyde  15  has  has been found t o  be the i n t e r m e d i a t e mainly r e s p o n s i b l e f o r c h a i n branching i n the o x i d a t i o n s of s e v e r a l hydrocarbons, propylene  1 7 - 2 0  and 2 - b u t e n e s " . 2 1  2 3  f o r example, propane  In the"low  temperature"  1(  6  (<300°C)  range, the a d d i t i o n of p e r o x i d e s t o r e a c t i o n mixtures  sometimes has the same e f f e c t on the i n d u c t i o n p e r i o d T as the a d d i t i o n of a c e t a l d e h y d e ^ .  But K i r k and Knox ^ have shown that  1  peroxides are unimportant  300°C, t i o n at  2  i n c h a i n b r a n c h i n g processes above  though hydroperoxides have been found i n n-butane  oxida-  315-345°C . 25  The r e a c t i o n s r e s p o n s i b l e  f o r formaldehyde  chain  11-15 branching are c o n s i d e r e d  HCHO + 0 HCO  + 0  t o be  2  HCO + H0  (8)  CO  (9)  2  -  2  + H0  2  The branching processes i n the o x i d a t i o n of acetaldehyde have been w e l l e s t a b l i s h e d , mainly by a s e r i e s of i n v e s t i g a t i o n s by McDowell and h i s co-workers.  The mechanism has been shown t o  be :2 6  CHgCHO CH3CO CH CCQ 3  CH  + 0 + 0  0  -  2  2  C  2 CH Csoo  C H  3  n  3  C ^ .  CH3C* 0  3  < )  CH C^  *-  ~  3 'oOH  (10)  2  CH3CC00  CH3CHO  +  + H0  CH3CO  0H  +  (12)  CH3CO  (13)  +0H  0-0-c£cH  3  + 0  2  (14)  nc It has been p o i n t e d out a c i d , r e a c t i o n (13),  i s mainly r e s p o n s i b l e  f o r chain branching  (<200°C) .  at low temperatures Between  that the decomposition of p e r a c e t i c  320°C  and  380°C,  however, the mechanism of 97  acetaldehyde o x i d a t i o n has been suggested t o be* CH3CHO + 0 CH3CHO + H0 2  CH3CO + CH3CO +  2  H0  2  — -  wall  HH00 2  2  2  as f o l l o w s :  Knox, however, has that perhaps OH The  questioned t h i s mechanism  i n s t e a d of HO2 i s the  Semenov t h e o r y ^ 1  and  proposed  main a b s t r a c t i n g  species.  assumes that b r a n c h i n g takes  from the b e g i n n i n g of the r e a c t i o n and that the T  has  induction  i s merely the time r e q u i r e d f o r the o v e r a l l r a t e t o be 17-21,28  able.  There i s evidence  , however, t o show that  processes which occur d u r i n g the i n d u c t i o n p e r i o d are  place  period observ-  the  different  from those that take p l a c e d u r i n g the a c c e l e r a t i o n p e r i o d .  These  evidences i n d i c a t e that d u r i n g the i n d u c t i o n p e r i o d , the branchi n g agent i s produced v i a a primary c h a i n process. of the  At the  i n d u c t i o n p e r i o d , a c e r t a i n minimum c o n c e n t r a t i o n  branching agent has  been accumulated and  end  of  the  o n l y then would c h a i n 29  branching take p l a c e .  On the other: hand, t h e r e  t o i n d i c a t e t h a t the i n d u c t i o n p e r i o d i s due an i n t e r m e d i a t e  i s a l s o evidence  t o the removal of  on the w a l l of the r e a c t i o n w a l l .  The  induction  p e r i o d ends when the w a l l becomes i n a c t i v e . Various  attempts have been made t o c o r r e l a t e the  i n d u c t i o n p e r i o d T w i t h i n i t i a l experimental c o n d i t i o n s .  In 30  the n-pentane o x i d a t i o n i n the c o o l flame r e g i o n , P r e t t r e  has  found that  " p e n t a d For butane and  totax  -o-tant.  22  2-butenes, Neiman and h i s co-workers  31 '  have  shown t h a t n TXP-P )  —E/RT ".constant  e  0  where P  Q  i s the minimum t o t a l pressure  be observed and n i s a  at constant  mixture r a t i o ,  at which a c o o l flame  can  constant.  C o o l flames have been shown t o generate from the of the r e a c t i o n v e s s e l and  spread o u t w a r d s  32  and  that  the  centre  8 temperature  of the r e a c t i n g mixture r i s e s 15-20°C b e f o r e the  appearance of a c o o l f l a m e . 3 3  of  I t i s obvious that t h e phenomenon  c o o l flames i s a chemical-thermal p r o c e s s .  There are two  s c h o o l s of thought with r e g a r d t o t h e cause of t h i s phenomenon. One holds t h a t the chemical processes i n a c o o l flame o x i d a t i o n i s very d i f f e r e n t from those encountered i n a slow  oxidation . 3 4  The other s c h o o l c o n s i d e r s t h e appearance of c o o l flames t o be i n s i g n i f i c a n t m a n i f e s t a t i o n s t o the o v e r a l l o x i d a t i o n p r o c e s s . 1  Each s c h o o l has found enough evidence t o support i t s p o i n t of view. I g n i t i o n occurs probably when the heat generated by o x i d a t i o n processes i s i n excess of the t o t a l heat has made a simple treatment of t h i s phenomenon  100  loss.  .  In f i g . 4,  the r a t e of heat e v o l u t i o n as a f u n c t i o n of temperature sented by e x p o n e n t i a l curves C]_, C  2  and C 3 .  Semenov  i s repre-  The r a t e of heat  l o s s , f o r reasons of s i m p l i c i t y ,  i s c o n s i d e r e d t o be l i n e a r w i t h  temperature.  the heat e v o l v e d equals the  heat l o s s .  At temperature T , For any s l i g h t  displacement i n temperature, the  system w i l l tend t o r e t u r n t o T . g  At T^, however, any lowering i  i n temperature w i l l make the system go t o T . s  which b r i n g s the temperature  Any f l u c t u a t i o n  above T^ w i l l cause an i g n i t i o n .  The curve C , r e p r e s e n t i n g some minimum c o n c e n t r a t i o n s of 2  r e a c t a n t s , i s tangent t o the l i n e of heat l o s s at T .  Any  c  higher c o n c e n t r a t i o n than t h e minimum r e p r e s e n t e d by C always cause an e x p l o s i o n .  2  will  By a p p l y i n g Semenov's theory o f  degenerate c h a i n branching and e q u a t i n g the heat e v o l u t i o n and heat l o s s at T , i t can be shown that c  9  T  Ts 4.  Fig.  m  S  Ti Temperature —  H y p o t h e t i c a l heat e v o l u t i o n (C]_, C , C 3 ) and heat l o s s ( s t r a i g h t l i n e ) against temperature. 2  (liccl_) T  c  2  E RT  InB  (15)  &  where f C C ] i s a f u n c t i o n o f c r i t i c a l c o n c e n t r a t i o n C  f u n c t i o n of s u r f a c e Arrhenius  and B i s a  area, heat t r a n s f e r c o e f f i c i e n t , volume,  f a c t o r and a c t i v a t i o n energy. Though  the g e n e r a l c h a r a c t e r i s t i c s of o x i d a t i o n pro-  cesses are q u i t e w e l l known, the mechanism f o r these processes aretstill  r a t h e r obscure.  The i n i t i a t i o n  reaction i s generally  b e l i e v e d t o be RH +  (16)  R + HO.  Or  T h i s r e a c t i o n i s h i g h l y endothermic and may proceed on the ,35 wall  A f t e r the o x i d a t i o n has proceeded somewhat, the main i s probably 3 6  path of a l k y l r a d i c a l p r o d u c t i o n H0 OH  2  + RH + RH  ——-  H 0 2  H0 2  2  + R  (17)  + R  (18)  10. The  a l k y l r a d i c a l probably r e a c t s w i t h oxygen very r a p i d l y R + 0  »- R 0  2  (19)  2  and t h e r e i s reason t o b e l i e v e that the peroxy r a d i c a l s so formed 37 are i n t h e i r e x c i t e d s t a t e There a r e two probably ways f o r t h e disappearance of the peroxy  radical 0  Aldehydes,  *tVv«*^,  etc.  (20)  RCv Abstraction  ROOH  - products  (21)  Evidence shows t h a t t h e decomposition route i s favoured by h i g h temperatures  (>250°C)  3  8  '  3  9  .  Minkoff and T i p p e r  2  suggest  that  the a b s t r a c t i o n r o u t e i s probably c o m p e t i t i v e at low temperatures Semenov  and S h t e r n  10c  1  favour t h e decomposition route and suggest  t h a t t h e decomposition i s always preceeded by t h e i s o m e r i s a t i o n of t h e peroxy r a d i c a l t o >C-0-0-C^  or ^C-O-O-H. 7  Recently, Knox has proposed a new mechanism t o account f o r t h e o x i d a t i o n o f alkanes and alkenes i n t h e temperat u r e range 300-400°C.  The primary product of t h e o x i d a t i o n of  alkanes i s c o n s i d e r e d t o be t h e "conjugate" alkene (an alkene w i t h t h e same number of carbon atoms as t h e parent alkane) v i a the f o l l o w i n g s t e p s : RH + 0 R  s -  2  + X  R + H0  2  AB + XH  where AB i s t h e conjugate alkene of RH and X i s an a b s t r a c t i n g species  (H0 , OH or 0 ) . 2  2  Further oxidation i s considered t o  take p l a c e mainly on t h e conjugate alkene AB as f o l l o w s :  11. AB  HOo  Oo " H0 ABOOH —4~ • OOABOOH «- HOOABOOH 2  where AO and BO are c a r b o n y l  products.  20H + AO + BO  T h i s mechanism  the OH r a d i c a l t o be t h e a c t i v e a b s t r a c t i n g s p e c i e s a conversion  from HOg t o OH.  is semi-quantltatively radical  considers  and i n c l u d e s  The negative temperature c o e f f i c i e n t  explained  i n terms of t h e s t a b i l i t y of t h e  ABOOH. The  s u g g e s t i o n t h a t conjugate alkenes are t h e primary  products i n t h e o x i d a t i o n of alkanes has been s u b s t a n t i a t e d i n s e v e r a l studies^»29,40-42^ though cyclohexene has been found i n 43 only s m a l l q u a n t i t i e s i n t h e o x i d a t i o n o f cyclohexane support o f the Knox mechanism, c a r b o n y l  .  Also i n  compounds have been found TO 91 O Q  t o be the i n i t i a l products of t h e o x i d a t i o n of alkenes  '  A  " ^ '  41,44-46 The olefins  d i s c u s s i o n so f a r a p p l i e s t o both p a r a f f i n s and  (and t o a l a r g e extent, t o other o r g a n i c  compounds).  There i s one important f e a t u r e p e c u l i a r t o o l e f i n s , that a d d i t i o n of r a d i c a l s t o the o l e f i n i c double bond.  i s , the  At 300°C, t h e  r a t e of a d d i t i o n o f e t h y l r a d i c a l s t o 1-heptene i s n e a r l y t h e same as t h e r a t e of e t h y l r a d i c a l a b s t r a c t i o n of hydrogen from 47 the same o l e f i n . In t h e l i q u i d phase, peroxy r a d i c a l s have AQ  been p o s t u l a t e d conditions one  t o add t o t h e o l e f i n i c double bond  of gas phase hydrocarbon o x i d a t i o n ,  . Under t h e  t h e a d d i t i o n of  a l k y l r a d i c a l t o an o l e f i n can cause t h e displacement of  another a l k y l r a d i c a l from t h e parent The  olefin^.  primary r e a c t i o n between ground s t a t e oxygen atoms,  0( P) , w i t h p a r a f f i n s  and acetaldehyde*"  c l o s e l y p a r a l l e l s the  12 m o l e c u l a r oxygen analogue.  Both reactions  t i o n s of hydrogen from the p a r a f f i n (or RH + 0 ( P ) B~  2  R + H0  abstrac-  acetaldehyde):  R + OH  3  RH + 0  i n v o l v e the  (22) (16)  2  50  There i s a l s o evidence f o r d i s p l a c e m e n t r e a c t i o n s , Me CH + O  f o r example  Me C0 + C H + H  3  2  3  The e x c i t e d s i n g l e t oxygen atom, O ^ D ) , however, behaves  (23) differ-  52 ently  .  It tends to i n s e r t RH  + 0( D)  itself  i n t o a C-H bond:  *~ ROH  1  (24)  The p r i m a r y r e a c t i o n between oxygen atoms and o l e f i n s i n v o l v e s e x c l u s i v e l y t h e a d d i t i o n of the oxygen atom t o o l e f i n i c double bond 0 + >C=CC  as  the  follows: (25)  ~>C—CC 0  A v e r y e x t e n s i v e study of the r e a c t i o n between ground s t a t e oxygen atoms and v a r i o u s o l e f i n s has been made by C v e t a n o v i c and his  coworkers  5 3 - 6 0  .  At low t e m p e r a t u r e s , the o x i d a t i o n o f hydrocarbons by oxygen atoms does not i n v o l v e c h a i n b r a n c h i n g p r o c e s s e s . oxygen atoms can be i m p o r t a n t temperatures, for 0 + C H 2  6 1  2  2  OH + C H H + 0 2  2  as c h a i n b r a n c h i n g agents at h i g h  example :  C H + C H 2  But  2  2  OH + C H 2  (26)  C H  + H  (27)  4  2  >- H 0 + C H *- OH + 0 (branching) 2  2  (28) (29)  :  13  Thus, at low temperatures,  the o x i d a t i o n of  hydro-  carbons by molecular oxygen p r o c e e d s d i f f e r e n t l y from the o x i d a t i o n by atomic oxygen, with the e x c e p t i o n of the i n i t i a l a b s t r a c t i o n process from p a r a f f i n s .  At high  hydrogen  temperatures,  however, both molecular and atomic oxygen p l a y s i m i l a r r o l e s i n oxidation processes. The present study i n v o l v e s the i n v e s t i g a t i o n s of the r e a c t i o n between oxygen atoms and 2-butenes and the o x i d a t i o n s of 2-butenes by molecular oxygen.  It i s hoped that the r e s u l t s  of the present i n v e s t i g a t i o n w i l l c o n t r i b u t e towards the unders t a n d i n g of o x i d a t i o n processes as a whole.  14  CHAPTER II THE REACTION BETWEEN 2-BUTENES AND OXYGEN ATOMS 1.  Introduction The reaction between 0-atoras and olefins  very widely studied.  has not been  Among known works, the series of studies  by Cvetanovic and his c o - w o r k e r s  5 3 - 6 0  are most valuable.  Other  works include studies by Avramenko and Kolesnikova and t h e i r c o - w o r k e r s , by E l i a s and S c h i f f , 62  6 3  by E l i a s ,  by Ford and  6 4  Endow , and very recently by Hughes, Scheer and K l e i n 65  condensed phase.  53,58^ r j  v e  and K l e i n  t  6 6  a n o v  at  i n the  The reactions of 0-atoms with c i s - and trans-  among other o l e f i n s ,  2-butenes,  6 6  j.  and S a t o , 5 5  c  has been studied by Cvetanovic  by E l i a s , 6 4  and by Hughes, Scheer  77-90°K.  Cvetanovic and his co-workers stiidied t h i s reaction at pressures of 50-600 mm Hg. Oxygen atoms were produced either by 53 mercury photosensitised  decomposition of nitrous oxide  the photolysis of nitrogen d i o x i d e . 5 5  or by  The 0-atom concentration  could not be determined in the system used by Cvetanovic and his co-workers but the amount of 0-atoms consumed was given by the nitrogen produced during the photolysis. analysed.  A l l products were  The main addition products found were c i s - and trans-  2,3-butene oxide,  isobutanal,  and methylethyl ketone.  amounts of "fragmentation" products of carbon monoxide, ethane,  Trace methane,  ethylene and acetaldehyde were also observed. 53 54c * Cvetanovic has proposed a mechanism  reactions between olefins  '  for the  and 0-atoms, suggesting that  the  primary step involves the addition of an 0-atom to the less  15 s u b s t i t u t e d C-atom at one end of the double bond of t h e hydrocarbon:  *3  Rl /C=C R The  (25)  x  R4  2  / 3 — C . ' 4 R  + 0  r e a c t i o n products  R  2  [  R  Q  are c o n s i d e r e d t o form as a r e s u l t of  "molecular rearrangements" groups,  l  R  i n v o l v i n g the m i g r a t i o n of a l k y l ( R )  i n c l u d i n g the H-atom, without  inter-molecular abstrac-  t i o n of H-atoms: R  l  R  3  2  R  )c-c  /C—C. R  /3  l  R  X  r 4  R  2  V  R  4  R  2  X  +  v  / + R i - C - C -R3 S 4 r  l  R  R  R  /C—  C  V  2  4  R  v  3  / i + R0C-C-R3 J R4 R  (30)  X  In the case of 2-butenes, these products are c i s - and t r a n s - 2 , 3 butene oxide, i s o b u t a n a l and methylethyl ketone. "Fragmentation"  products are c o n s i d e r e d t o a r i s e  the s p l i t t i n g o f f of m i g r a t i n g groups,  from  and the decomposition of R  "hot" a d d i t i o n products and of the i n i t i a l  adduct  C  R  L a t e r i n the study of t h e e f f e c t  ^R** tt S f i / "C^ °- » 2 0 4 l v  of molecular  on the r e a c t i o n of 0-atoms with c i s - 2 - p e n t e n e S a t o  5  OD  R  oxygen  and L •  57 Cvetanovic  made more d e t a i l e d s u g g e s t i o n s about the nature of  the "fragmentation" p r o c e s s .  The f o r m a t i o n of 2-methyl b u t a n a l  was c o n s i d e r e d t o be made by an " e x t e r n a l " rearrangement  reaction:  16 C H CH-CHCH 0• 2  5  C H CH-CHCH °  3  2  5  ^ CnHe + C H CH-CHCHo* C _ 0 2  5  x  /  3  *  v  C H  3  CpHc  C C H C H C H n ^  °  + CCHCHC H -^CH o  2  5  " >  C  H  C  H  <  0  3 1 )  3  In t h e case of the 0-atom r e a c t i o n with 2-butene, the formation of i s o b u t a n a l can be e x p l a i n e d i n an analogous way:  CHJ CH-CHCH - i 3 0  CHoCH-CHCHo * J \ s 3  0  6  CHoCH-CHCHo* "0' 3  3  It s h o u l d be noted,  Q  CH„ *- CHo + CHoCHCHO — C H C H O CH ^ 3  (32)  3  3  however, t h a t t h i s r e a c t i o n p r e d i c t s t h e  f o r m a t i o n o f only methyl r a d i c a l s from the 0-atom r e a c t i o n w i t h 2-butenes. Ford and Endow  s t u d i e d the r e a c t i o n s between 0-atoms  and v a r i o u s hydrocarbons u s i n g a method s i m i l a r t o Cvetanovic's, a l s o u s i n g t h e p h o t o l y s i s of n i t r o g e n d i o x i d e t o generate They were mostly  0-atoms.  i n t e r e s t e d i n the r e l a t i v e r a t e s of t h e r e a c t i o n s  Kaufman measured the absolute rate^-**'^ of t h e r e a c t i o n between 0-atoms and e t h y l e n e i n a system s i m i l a r t o the one used by  go E l i a s and S c h i f f mainly  t o be d e s c r i b e d l a t e r , but made t h i s  study  as an a p p l i c a t i o n of h i s method of 0-atom g e n e r a t i o n . 6 2  Avramenko and K o l e s n i k o v a and t h e i r co-workers  made  s e v e r a l s t u d i e s on t h e r e a c t i o n s between 0-atoms and s e v e r a l o r g a n i c compounds, i n c l u d i n g methane, ethane, ethylene, isobutene  and acetaldehyde.  trode d i s c h a r g e s i n molecular  0-atoms were generated  propylene,  by the e l e c -  oxygen or water vapour.  In the  former case, the r e a c t i o n s were complicated by a l a r g e excess of  17 molecular oxygen. be produced  In the l a t t e r case, hydroxy  r a d i c a l s would  i n e q u i v a l e n t c o n c e n t r a t i o n s t o the 0-atoms and the  62a authors p o i n t e d out  that the OH r a d i c a l a t t a c k was a c t u a l l y  f a s t e r than the O-atom a t t a c k .  The main products f o r O-atom-02  mixture r e a c t i o n s w i t h ethylene, propylene and isobutene was found t o be formaldehyde.  Avramenko and K o l e s n i k o v a concluded  t h a t the primary step was the C=C bond s c i s s i o n ,  f o l l o w e d by the  formation of H 2 O and the i n c o r p o r a t i o n o f an O-atom i n t o a C-H bond.  Both the r e s u l t s and the c o n c l u s i o n s were i n d i r e c t  disagreement  w i t h the f i n d i n g s of C v e t a n o v i c .  E l i a s and S c h i f f  6 3  and l a t e r E l i a s  r e a c t i o n of 0-atoms w i t h hydrocarbons pressures.  6 4  s t u d i e d the  i n a flow system  at low  The 0-atoms were generated through t i t r a t i o n of :  n i t r i c oxide against a stream of N-atoms o b t a i n e d from a microwave d i s c h a r g e i n molecular n i t r o g e n .  The O-atom c o n c e n t r a t i o n  was monitored p h o t o m e t r i c a l l y through the emission of the O-atom r e a c t i o n w i t h a constant s m a l l excess of n i t r i c 0 + NO The hydrocarbon  -  N0  2  oxide:  + hy  (33)  c o n c e n t r a t i o n was f o l l o w e d by measuring the  consumption of the hydrocarbon  d u r i n g v a r i o u s stages of the  r e a c t i o n , u s i n g a m e t a l l i c oxide probe t o stop the r e a c t i o n at the d e s i r e d p o i n t . cc  Very r e c e n t l y Hughes, Scheer  and K l e i n  0 0  have s t u d i e d  the r e a c t i o n s between 0-atoms and propylene and 2-butenes i n the condensed phase i n the temperature were produced  range of 77-90°K.  0-atoms  by p a s s i n g molecular oxygen over heated rhenium  ribbons at 2300°K.  These authors found that at these low  18 temperatures, the primary a d d i t i o n products were e f f e c t i v e l y stabilised Cvetanovic  and t h a t the products were the same as found by i n a d d i t i o n t o ozonides and acetaldehyde.  p o r t i o n of acetaldehyde was  The major  found t o be produced by the a c t i o n of  ozone on 2-butene, but a s m a l l q u a n t i t y was  produced  as a r e s u l t  of the primary a c t i o n of the 0-atoms on the  hydrocarbon.  For the r e a c t i o n 0 + C H 2  „  4  (34)  the v a l u e s of the r a t e constant k workers  3 4  o b t a i n e d by t h r e e groups of  are as f o l l o w s : Elias  k  4 5  Cvetanovic  4 0  '  4 1  k  3 4  3 4  = 8.4xl0  9  = 5.7xl0  8  e  Avramenko & Kolesnikova  k  3 4  = 6.0xl0  7  = 6.1xl0  6  1  6  0  0  /  R  1  T  mole'~ sec~  1 mole^sec-  = 1.43x10 = 1.74xl0  "  10 e  -  2 6 0  e~  1  3  5  mole^sec"  R  0  /  R  - 1  sec  T  1  , 1 mole'sBec"*  at 25°C  _ 1  mole~ sec~ 1  1  at 25°C  64 E l i a s p o i n t e d out  t h a t the main reason f o r the d i f f e r e n c e i n  v a l u e s o b t a i n e d by h i m s e l f and by C v e t a n o v i c l a y i n the ent v a l u e s of a c t i v a t i o n energy o b t a i n e d . been determined e a r l i e r by E l i a s experimental system,  and S c h i f f  value  5 8 , 5 9  was  differ-  E l i a s ' s v a l u e has 63 in a similar  and i n both d e t e r m i n a t i o n s , the r a t e  s t a n t s were measured over s e v e r a l temperatures.  1  at 25°C  1  °/ Tl  1 mole  8  1  con-  Cvetanovic's  based on an a c t i v a t i o n energy of 0.1-0.3 k c a l /  mole f o r the r e a c t i o n of 0-atoms w i t h t e t r a m e t h y l - e t h y l e n e , and the r e l a t i v e v a l u e s f o r the v e l o c i t y c o n s t a n t s were determined  1  1  19  over o n l y two temperatures.  Rate constant determinations by  Avramenko and K o l e s n i k o v a were made i n a system i n v o l v i n g the e l e c t r o d e discharge of molecular oxygen and the value given i s l i k e l y t o be somewhat i n e r r o r . For the r e a c t i o n 0 + cis-2-Butene  >.  (35)  E l i a s gave the f o l l o w i n g v a l u e * f o r t h e r a t e constant 0  k  = 2.3xl0  3 5  1 0  = 1.26xl0  e  10  -  3 6  °/R  1 mole-isec-  T  1 mole sec at - 1  1  25°C  - 1  58 C v e t a n o v i c ' s value at the same temperature i s k  = 3.9xl0  3 5  9  1 mole~ sec" . 1  1  He d i d not make any d e t e r m i n a t i o n of the a c t i v a t i o n  energy.  Absolute r a t e constants o b t a i n e d by Cvetanovic^® were based on the d e t e r m i n a t i o n o f r e l a t i v e r a t e constants and on a value of 2.1x10  1 mole~- -sec  f o r t h e r a t e constant of the  l  60  0 + N0 was  2  r e a c t i o n found by F o r d and Endow  T h i s value, however,  i n t u r n based on the r a t e constant f o r t h e r e a c t i o n O+O2+M  obtained by Benson and A x w o r t h y ^ . The major reason f o r the d i f f e r e n c e s i n t h e v a l u e of r a t e c o n s t a n t s of t h e 0-atom r e a c t i o n with ethylene (and other o l e f i n s ) seems t o l i e i n t h e s p e c i e s measured. by Cvetanovic  CO 0  Rate measurements  were made on t h e amount of oxygenated products 64  produced, while those of E l i a s  were made on the consumption of  the o l e f i n and t h e a c t u a l c o n c e n t r a t i o n of the 0-atoms. authors assumed 0 + O l that efin  ^  Both  20 was  the only r e a c t i o n which they were measuring and t h a t t h i s  was  the r a t e c o n t r o l l i n g s t e p .  used by C v e t o n o v i c  5 4 a  ,  Under the experimental c o n d i t i o n s  the t o t a l pressure was  high enough so  that the hot products of the r e a c t i o n c o u l d mainly be a l l y deactivated.  T h i s was  collision-  evidenced by the s m a l l amount of  "fragmentation" products except  i n the case of e t h y l e n e .  i f the value of the r a t e constant f o r the r e a c t i o n O + was  accurate, the absolute r a t e constants  e  Q  '  HQ  N0  estimated  Cvetanovic should be r a t h e r c l o s e t o the t r u e v a l u e .  Thus, 69 2  by  Under the  64 experimental pressures used by E l i a s  , however, O-atom con-  c e n t r a t i o n s along the r e a c t i o n tube were a c c u r a t e l y known but secondary  r e a c t i o n s would be e x t e n s i v e and the r a t e of d i s a p -  pearance of the o l e f i n would not l i k e l y be a t r u e measure of the r a t e of the r e a c t i o n 0 + Olefin That  *-  h i s value i s about t h r e e times the value obtained by 64  Cvetanovic i s thus q u i t e understandable. that secondary  Elias  r e a c t i o n s of the s p e c i e s X(H,  ethylene would be important  OH,  i n the flow system.  suggested etc.) with He s t a t e d  that the r a t e of disappearance of ethylene would then be - d(Ethylene) * (o)(Ethylene) dt =  where u  was  ( 1  +  )  k 3 4  the amount of X formed. In order t o agree t o  Cvetanovic's v a l u e  5 8  of a c t i v a t i o n energy,, E l i a s found t h a t  would need t o be about 3.  T h i s was  c o n s i d e r e d t o be u n l i k e l y .  Another aspect of the r e a c t i o n between 0-atoms and o l e f i n s t h a t has not been s a t i s f a c t o r i l y e x p l a i n e d i s the  21 disappearance  of t h e 0-atoms.  In the r e s u l t s presented by  53 54a Cvetanovic  '  the t o t a l y i e l d of products per oxygen atom;  was always l e s s than 1.  The y i e l d per oxygen atom f o r oxygen-  c o n t a i n i n g products rose from about zero at low p r e s s u r e s t o a steady value above 200 mm p r e s s u r e , as shown i n F i g . 5. E l i aC Os and S c h i f f i n t h e i r study *of reaction ( 0 )t h e 0-atom w i t h ethylene , have found that the — r a t i o decreases A (Ethylene) from 2.3 i n i t i a l l y t o about 1 f a r t h e r down the flow tube. Kauf67 man  has found a two- t o t h r e e - f o l d molar excess of t h e 0-atom  disappearance  compared with t h e ethylene consumption, i n h i s  e a r l y study of t h e 0-atom r e a c t i o n with e t h y l e n e i n a flow system. Thus i t i s apparent  that 0-atoms are o n l y p a r t i a l l y  consumed i n r e a c t i o n s w i t h t h e o l e f i n s . f o r by secondary  They cannot  r e0.4 a c t i o n s with hydrocarbon  be accounted  r a d i c a l s , because  <*-Bufene oxide  •  E o +-  S  n-Butanal  0.3  I  O 0.2 Q-  CO .3>  o./  >-  Bu+anone _o loo  200  9  300  400  mm  Pressure Fig,  E f f e c t of p r e s s u r e on t h e y i e l d per oxygen atom i n t h e r e a c t i o n 0+butene-l by C v e t a n o v i c . 5 4 a  22 the t o t a l oxygen-containing products per O-atom found by 53 Cvetanovic  54 '  have always been s i g n i f i c a n t l y  l e s s than  In d i s c u s s i n g the r e s u l t s of experiments  one.  of the  iodine  atom c a t a l y s e d geometric i s o m e r i s a t i o n of 2-butenes, Back and 71 Cvetanovic  postulated  an iodine-butene  Tr-complex such that  the f o l l o w i n g path would be p a r t i a l l y r e s p o n s i b l e  f o r the r e -  combination of the i o d i n e atoms: —».  cis-2-butene: I complex + I  cis-2-butene + Io  .V436) Moreover, Cvetanovic p o s t u l a t e d  a TT-complex f o r m a t i o n as a  process f o r the i n i t i a l a t t a c k of an O-atom at an o l e f i n i c double b o n d , but d i d not p o s t u l a t e 6 0  an O-atom r e c o m b i n a t i o n ;  p a t h ' s i m i l a r t o r e a c t i o n (36) above. unaccountable  In view of the amount of  0-atoms i n O-atom-olefin r e a c t i o n s , such a path  seems h i g h l y p l a u s i b l e . In another study of the i o d i n e atom c a t a l y s e d 72 i s o m e r i s a t i o n of 2-butenes, Benson et a l showed that cis-2-Butene + I — was  \  —  geometric  f ' I.  (37)  not the r a t e c o n t r o l l i n g step, but the f o l l o w i n g process  i n v o l v i n g a r o t a t i o n about  the C-C  bond was  probably  quite  important:  (38) There i s a c o n s i d e r a b l e  of Back and Cvetanovic  71  disagreement  and of Benson et a l  72  between the works .  Back and  Cvetanovic generated i o d i n e atoms from molecular i o d i n e chemically  photo-  and Benson et a l used thermal processes f o r the  p r o d u c t i o n of i o d i n e atoms.  The r e s u l t s of Back and Cvetanovic  23 l e a d t o the r a t e e x p r e s s i o n d ( c i s - t r a n s isom.) dt where I  =  k  (cis-2-butene)^(I )* I 2  r e p r e s e n t s absorbed  intensity.  The  < > 39  a  **  rate expression  found by Benson et a l at low c o n v e r s i o n s i s somewhat d i f f e r e n t , namely: -  d  (  c  i  s  ^ 2  B  u  t  e  n  e  - k(cis-2-butene)(I )^  )  ( 4 0 )  2  = k(cis-2-butene) (I)  (40a)  72 Moreover, the paper by Benson et a l , although p u b l i s h e d more than a year l a t e r ,  i n c l u d e d no mention of the work of Back  and  71 Cvetanovic In may  any case, the i n i t i a l  a t t a c k of 0-atoms on  be very s i m i l a r t o the i o d i n e atom analogue.  study was  made i n order t o determine  The  olefins  present  whether the process  O + 2-Butenes  »-  i s r a t e c o n t r o l l i n g and t o determine  (41)  the mechanism by which the  r e a c t i o n products are formed. The method of producing 0-atoms i n the present cq  is  CA  cn  study  ft  q u i t e w e l l e s t a b l i s h e d *>>°^> >'* ol  > a  n  (  j depends on the  microwave d i s c h a r g e g e n e r a t i o n of n i t r o g e n atoms from  initial molecular  n i t r o g e n and subsequent t i t r a t i o n against n i t r i c oxide t o "extinction".  The r e a c t i o n can be r e p r e s e n t e d by N + NO  If the NO  »- O + N  (42)  2  flow i s l a r g e r than the N-atom flow, the  would occur and t h e r 0e would be an N0 emission. + NO + hi> 2  "extinction" point, NO flow = 0-atom flow.  reaction  T h e r e f o r e , at(43) the  24 Thus t h i s study was absence of molecular oxygen.  c a r r i e d out e s s e n t i a l l y Reactions between  i n the  hydrocarbons  and 0-atoms generated by the microwave d i s c h a r g e of molecular oxygen have been shown 62 results  different  molecular oxygen.  57  '  88  t o i n v o l v e c o m p l i c a t i o n s and g i v e  from the r e a c t i o n s i n the absence of In the present study, t h e r e f o r e , such  c o m p l i c a t i o n s were avoided and i t was  expected that more  meaningful r e s u l t s would be l i k e l y t o be o b t a i n e d .  25 2.  Experimental D e t a i l s (i)  Apparatus  a. Flow  reactor  A schematic diagram of t h e flow r e a c t o r system i s shown i n F i g . 6.  The Pyrex r e a c t i o n v e s s e l was about 70 cm long  with an i n t e r n a l diameter of 17 mm. outer diameter t u b i n g .  The f i r s t  I n l e t j e t s were made of 5 mm  butene i n l e t  j e t was 1.0 ;cm  from t h e n i t r i c oxide i n l e t j e t . Both the butene i n l e t j e t s and the c a p i l l a r y t r a p s were spaced 5 cm apart. were made of 1.5 mm i n t e r n a l diameter t u b i n g .  The c a p i l l a r y  traps  The main U-trap  was made of 15 mm outer diameter t u b i n g and had a volume of 165 c c .  The main pump used was a Cenco Hyvac 7.  The MacLeod  gauge was an Ace G l a s s r o t a t i n g type and was capable of measuri n g up t o 5 mm p r e s s u r e . An o p t i c a l bench was mounted p a r a l l e l t o t h e f l o w reactor.  A phototube mounted on t h i s o p t i c a l bench c o u l d be  used t o f o l l o w t h e i n t e n s i t y of t h e NO + 0 e m i s s i o n . The microwave generator used was a Raytheon M i c r o therm u n i t , o p e r a t i n g at 2450 mc'(wavelength  12.2 cm) and  capable of a maximum of 125 watts r a d i a t e d power. K e l - F grease was used i n the vacuum system and i t had no e f f e c t on the r e s u l t s of t h e experiments.  b. N i t r o g e n metering system The n i t r o g e n admission system i s shown s c h e m a t i c a l l y i n F i g . 7.  N i t r o g e n from a commercial c y l i n d e r , a f t e r p a s s i n g  through a rough r e g u l a t o r , was passed through a Matheson "Pancake"  regulator.  N i t r o g e n p r e s s u r e was reduced t o 1 p . s . i . g .  Fig.  6.  The Flow Reactor  System.  Microwave guide  z-Butene  \  Microtherm Unit  To MacLeod 3 9 a u  e  m u  To  i  i  XD=^  pumping System  N O  y T T T T f c To G a s Chromatography System To high vacuum  Traps  27 Pressure gauge T o flow reactor  F r o m  N  2  cylinder  I  p  w  M  |  (  e  . Needle valve  Dry ice trap Flow meter  Fig. 7. at t h i s p o i n t .  N i t r o g e n Metering System.  An Edwards h i g h vacuum needle v a l v e was used  t o r e g u l a t e t h e admission  i n t o t h e flow r e a c t o r .  S e a l " pump o i l was used i n t h e flow meter.  Welch "Duo-  C a l i b r a t i o n was  made both by measuring the volume of e f f l u e n t from t h e pump at steady s t a t e c o n d i t i o n s and by t r a p p i n g a condensable  gas and  weighing i t .  c. N i t r i c oxide metering The  system  n i t r i c oxide admission system was s i m i l a r t o t h e  n i t r o g e n one, with the e x c e p t i o n of t h e "Pancake" r e g u l a t o r and the d r y i c e t r a p .  A f i n e p r e s s u r e adjustment  was not a v a i l a b l e  i n t h i s case, but t h e p r e s s u r e of NO was maintained p.s.i.g.  at a few  A t r a p of F i s c h e r " I n d i c a r b " was used t o absorb any  t r a c e of NO2, C 0  2  and water present i n t h e NO.  d. Butene metering  system  The butene metering system was again s i m i l a r t o the n i t r o g e n one. A c y l i n d e r of butene:,' p r e v i o u s l y degassed, was  28 p l a c e d i n an i c e bath.  Butene was  allowed t o pass d i r e c t l y t o  the Edwards h i g h vacuum needle v a l v e through a rough Matheson needle v a l v e .  ( i i ) The Gas Chromatography System The gas chromatography system,  shown i n F i g . 8,  was  made of Pyrex t u b i n g , w i t h the e x c e p t i o n of the Perkin-Elmer detector parts.  B a l l j o i n t s were used t o connect the column  t o the system so t h a t s e v e r a l columns c o u l d be i n t e r c h a n g e a b l e . The whole system was  wrapped with h e a t i n g tapes except the  t h e r m o s t a t i c box c o n t a i n i n g the Perkin-Elmer d e t e c t o r s . grease was joints.  used t o l u b r i c a t e and s e a l the stopcocks and  A f t e r some use, the grease would r e t a i n ,  and  l y would emit, on every t u r n of the stopcocks (1) and very s m a l l amount (about 10  wire  i n s i d e two  h e a t i n g wire was  ball  subsequent(2), a  of normal sample s i z e ) of  The column heater was  Kel-F  butene.  made from a c o i l of nichrome  l a r g e diameter g l a s s tubes as i n s u l a t o r s . connected d i r e c t l y t o a V a r i a c .  The  No t h e r m o s t a t i c  d e v i c e was used, but d u r i n g a p e r i o d of s e v e r a l hours, the temperature  c o u l d be maintained t o about ± 0.5°C.  Both the t h e r m i s t o r and f l a m e - i o n i z a t i o n d e t e c t o r s were o r i g i n a l equipment i n a Perkin-Elmer  Vapour-Fractometer  Model 154.  The flow path was  arranged such t h a t the sample  would f i r s t  f l o w through the t h e r m i s t o r d e t e c t o r and then a  p o r t i o n of i t would go t o the f l a m e - i o n i z a t i o n d e t e c t o r . d e t e c t o r s were u s u a l l y used s i m u l t a n e o u s l y . Northrup Speedomax G r e c o r d e r s (5 mv range,  Two  Both  Leeds and  1 sec response,  and c h a r t speed at 30 i n per hour) were used.  F i g . 8.  Gas Chromatography System.  thermistor and flame ionisation defectors  Helium  30 During a run, helium gas would flow through the sampling bypass w h i l e the sampling b u r e t t e was through stopcocks (3) or ( 4 ) . r e a c t o r was  evacuated  A sample t r a p p e d from the flow  then allowed t o expand i n t o the sampling b u r e t t e .  With stopcocks (3) and  (4) c l o s e d ,  (1) and  (2) were t u r n e d  s i m u l t a n e o u s l y , a l l o w i n g the helium t o sweep through the sampling b u r e t t e . The f o l l o w i n g columns were used f o r the  purposes  indicated:1.  M o l e c u l a r s i e v e s 5A, f o r the s e p a r a t i o n of CO,  2.  N, 2  and  0 ; 2  Perkin-Elmer Column J ( s i l i c a g e l ) , f o r the s e p a r a t i o n of C 1 - C 3  3.  hydrocarbons;  HMPA (hexamethylphosphoramide) on F i s h e r Columnpak, f o r the s e p a r a t i o n of  light  hydrocarbons; 4.  DNP  ( d i n o n y l p h t h a l a t e ) on f i r e b r i c k ,  s e p a r a t i o n of l i g h t oxygenated 5.  F & M P-0190 Column (20%  f o r the  products;  nonylphenoxypolyT,;  e t h a n o l on chromosorb P.A.W. 60-80 mesh) f o r the s e p a r a t i o n of oxygenated  products.  E l u t i o n time c a l i b r a t i o n s f o r the Perkin-Elmer Column J i s shown i n Table 1.  31 T a b l e 1. E l u t i o n time c a l i b r a t i o n s f o r t h e P e r k i n Elmer Column J . C a r r i e r gas: helium. Pressure: 8 p.s.i.g.  E l u t i o n Time i n minutes Compound Air Methane Ethane Carbon d i o x i d e Ethylene Acetylene Propane Cyclopropane Propylene Isobut ane n-But ane  23°C 135 cc/min  75°C 88 cc/min  2.8 3.5 6.2 6.9 8.4 18.7 20.4 39.6 46.2 54.0 62.8  2.1 3.6 5.1 9.4 17 .8 30 34  Table 2 shows t h e e l u t i o n time c a l i b r a t i o n s f o r t h e HMPA Column. T a b l e 2. E l u t i o n time c a l i b r a t i o n s f o r t h e HMPA Column at 0°C. C a r r i e r gas: helium. P r e s s u r e : 8.5 p . s . i . g . Flowrate: 37 cc/min. Compound Air Methane Ethane Ethylene Propane Propylene Isobutane Cyclopropane n-rButane Acetylene Isobutene Allene . trans-2-Butene cis-2-Butene  E l u t i o n Time i n min 3.5 5.4 5.8 6.0 7.1 8.0 8.6 11.4 11.4 11.6 14.7 17.0 18.2 20.2  32 T a b l e 3. E l u t i o n times and r e l a t i v e s e n s i t i v i t i e s f o r the DNP Column at 57-58°C. C a r r i e r gas: helium. P r e s s u r e : 5 p.s.i.g. Flowrate: o l d p a c k i n g 86 cc/min, new packing 55 cc/min. E l u t i o n Time i n minutes Compound Air Methane, ethane, ethylene Propane Isobutane n-But ane Isobutene trans-2-Butene cis-2-Butene Acetaldehyde trans-2-Pentene cis-2-Pentene Diethyl:ether 1,2-Propene oxide Acrolein cis-4-Methylpentane-2 trans-4-Methylpentene-2 2- Nitropropane Propanal D i a c e t y l peroxide cis-2,3-Butene oxide Formaldehyde Nitromethane Nitroethane Acetone Methanol Water trans-2,3-Butene oxide Isobutanal Propanol-2 Ethanol Butanal Butanone-2 Biacetyl A l l y l alcohol Butanol-1 Propanol-1 1-Nitrobutane Butanol-2 Crotonaldehyde Pentanone-3 3- B u t e n e - l - o l 1-Nitropropane  Old packing 1.6 1.8 2.0 2.4 2.7 3.0 3.1 3.2 4.7 5.3 5.4 6.0 7.0 7.6 7.8 8,1 9.0 9.8 10.6 10.7 11.0 11.0 11.6 12.7 13.1 14.0 15.5 19.3 22.6 25.0 27.5 28.0 30 34 44 45 52 69  New packing 1.8  2.6 3.4  5.7 6.0  Relative Sensitivity  0.75 0.61 0.69 0.55 0.63 1.0 1.0 1.0 0.67  6.8 6.9 8.8 7.0  0.45  7.4 5.4 8.1 11.3 10.0 11.1 8.5 13.4 15.2 16.0 20.3 51.0 20.3  0.45  34 35 45  0.48 0.84 0.79 0.54  1.55  33 T a b l e 3 shows the e l u t i o n time and r e l a t i v e s e n s i t i v i t y c a l i b r a t i o n s f o r the DNP  Column.  Relative  s e n s i t i v i t i e s with  r e s p e c t t o 2-butenes were made by p a s s i n g mixtures of known composition through the column and measuring the peak area. The e l u t i o n times on the DNP t o temperature changes.  A difference  Column was  sensitive  of 10% i n e l u t i o n time  c o u l d e a s i l y be c r e a t e d by a d i f f e r e n c e temperature.  rather  of about 2°C i n column  F i g . 9 shows a p l o t of e l u t i o n times at 57-58°C  against those at room temperature  (23°C).  T a b l e 4 shows the e l u t i o n time c a l i b r a t i o n s f o r the F & M Column. T a b l e 4. B l u t i o n time c a l i b r a t i o n s f o r the F & M Column at 56°C. C a r r i e r gas: helium. P r e s s u r e : 5 p . s . i . g . Flowrate: 34 cc/v':.  r; ,:,; - :•• -IXXDA  min. '  Compound  E l u t i o n Time i n min 3.6 4.2 4.6 5.6 8.1 , 8.1 9.0 10.4 13.1 13.7 15.2 15.5  L i g h t hydrocarbons 2-Butenes D i e t h y l ether Acetaldehyde Propanal cis-2,3-Butene oxide Isobutanal trans-2,3-Butene oxide Butanal Methanol Butanone-2 Acetone ( i i i ) Material a. c i s - and trans-2-Butenes  I n i t i a l l y P h i l l i p s Pure grade c i s - and trans-2-butenes were used.  These were b e t t e r  than 99 mole % pure, as c l a i m e d .  I m p u r i t i e s , analyzed by gas chromatography, 1-butene,  i n c i s - 2 - b u t e n e were  isobutene and trans-2-butene. Research grade butenes were a v a i l a b l e l a t e r d u r i n g t h e  study.  About 0.1 mole % of the wrong geometric isomer was present  i n each isomer as claimed.  No s i g n i f i c a n t  d i f f e r e n c e was observed  between u s i n g pure grade and r e s e a r c h grade 2-butenes,  except  that O-atom c a t a l y z e d c i s - t r a n s i s o m e r i z a t i o n s t u d i e s had t o be done w i t h r e s e a r c h grade c i s - 2 - b u t e n e . No other p u r i f i c a t i o n other than degassing was made t o the 2-butenes  b e f o r e use.  b. N i t r o g e n  .,.  Canadian L i q u i d A i r Co. Pure grade n i t r o g e n was used. A f t e r p a s s i n g through a d r y i c e t r a p at 1 p . s . i . g . , t h e gas cont a i n e d an i m p u r i t y of 0.044% oxygen. c. N i t r i c oxide Matheson s u p p l i e d NO was used. 0.62%  N  2  and 0.37% N0 . 2  I m p u r i t i e s c l a i m e d were  A F i s h e r " I n d i c a r b " t r a p was p l a c e d i n  the metering l i n e t o absorb t h i s N0 . 2  d. Other compounds Compounds used f o r c a l i b r a t i o n purposes were o b t a i n e d from normal commercial s o u r c e s . (iv) Analysis a. I d e n t i f i c a t i o n of Products I d e n t i f i c a t i o n o f products was made mainly by comparing the gas chromatographic e l u t i o n time o f an unknown sample w i t h t h a t of a known compound f o r at l e a s t two d i f f e r e n t columns.  chromatographic  36 Hydrocarbon  products were p o s i t i v e l y i d e n t i f i e d on t h e  Perkin-Elmer J Column, t h e HMPA column and t h e DNP column.  Hydro-  carbon s e p a r a t i o n f o r t h e J column and t h e HMPA column, as seen i n T a b l e s 1 and 2, was very good and hydrocarbon  product  identifi-  c a t i o n was very r e l i a b l e and s a t i s f a c t o r y . Oxygenated products were i d e n t i f i e d on t h e DNP and the F & M columns.  Since t h e s e p a r a t i o n s were not very good,  i d e n t i f i c a t i o n was d i f f i c u l t .  Attempts  complete  were made, f o r example, by  lowering the column temperature,  t o e n l a r g e t h e s e p a r a t i o n ; but  these were not very s u c c e s s f u l .  Attempts  were a l s o made t o t r a p  compounds separated by chromatography and t o s u b j e c t them t o i n f r a red  and p r o t o n magnetic  resonance  spectroscopy.  were u n s u c c e s s f u l due t o s e v e r a l f a c t o r s . to products was low and chromatographic  These  attempts  Conversion from butene  s e p a r a t i o n was not good.  It was not p o s s i b l e t o i s o l a t e a pure enough sample and i n s u f f i cient quantity for a clear Fig.  spectrum.  10 shows a t y p i c a l r e s u l t o f a gas chromatographic  a n a l y s i s on t h e Perkin-Elmer J column, u s i n g both t h e thermal c o n d u c t i v i t y and the flame i o n i z a t i o n d e t e c t o r s .  F i g . 11 shows a  s i m i l a r a n a l y s i s on t h e HMPA column, F i g . 12 an a n a l y s i s on t h e DNP column and F i g . 13 on t h e F & M column, b. Q u a n t i t a t i v e measurement Q u a n t i t a t i v e measurements were made on t h e peak areas of the c h a r t from t h e flame i o n i z a t i o n d e t e c t o r .  Since t h e a b s o l u t e  s e n s i t i v i t i e s of t h e flame i o n i z a t i o n d e t e c t o r were not v e r y r e p r o d u c i b l e , r e l a t i v e measurements were made, w i t h 2-butenes as an i n t e r n a l standard.  Thus a l l measured peak areas were m u l t i p l i e d  CH x8  74°C 8 p . s . i . g . Helium c a r r i e r Run 133. C0 xi  2  4  (0  ai  O  00 4 p p3 4 0 »d 0 4 o a Ho 0e to  (D  0 3  HN P  o  •  to •  c+  •  0 S3  .  M'  a c+  a>  o c+  a (D  t-"  3  o  x8  Propanal  x 6400 x i o o Propane  6£  2- Butenes  5  c+  P  9  P M «<  CD  H-  CO  0 0 rr  cr (D  A  ml  cr+  o  3  3  O 3 3'  I—' CO  C H(D 9 P H 3 Hout C to 3 • M O 0 3 p H- H 01 M jB  p-  rt- CD H- 4 O • 3  •0 hi O  a c o  rt3 1—  1  << V) HCO  O tn o CD Oi 3 rt- 0 CD O rtO rtCD O cn H *i S3  N  o  CO  3  •  S  UP  o o  3* •  1—  1  e  3 13  X 32 x too  tra»s-2,3-&«d*ne oxid« and cis-2,3-Butene  xioo  —  Propanal  — x too  Aceialdehyde x8oo  X 2 0 0  o  Isoburanal  oxide  Ligfct  2-Bufer»es  Hydrocarbons  41. by t h e r e l a t i v e s e n s i t i v i t i e s shown i n Table 3 and compared w i t h the peak area f o r 2-butenes.  Since o n l y t h e r e a c t i o n o r d e r s  with r e s p e c t t o each i n i t i a l r e a c t a n t were the main o b j e c t s of the q u a n t i t a t i v e measurements, the accuracy of the v a l u e s f o r r e l a t i v e s e n s i t i v i t y was c. Peroxide  unimportant,  analysis  The method f o r peroxide a n a l y s i s was based on one by Young, V o i g t and Nieuwland^ . 4  A s t o c k s o l u t i o n of ammonium  t h i o c y a n a t e was made by d i s s o l v i n g 5 gm AR grade ammonium t h i o c y a n a t e and 5 ml AR grade 6N s u l p h u r i c a c i d i n methanol t o make up 1 l i t r e .  S h o r t l y b e f o r e t h e peroxide a n a l y s i s , some of  t h i s s t o c k s o l u t i o n was s a t u r a t e d ( i n t h e order o f 0.1 gm i n 50 ml) w i t h AR grade f e r r o u s ammonium s u l p h a t e , t o make a s a t u r ated s o l u t i o n of f e r r o u s t h i o c y a n a t e . A sample trapped i n t h e main U-trap of t h e flow r e a c tor  was t r a n s f e r r e d t o a s m a l l e r , removable t r a p by d i s t i l l a t i o n .  The  removable t r a p was then detached  immediately,  from t h e flow r e a c t o r and,  and a l i q u o t of t h e f r e s h l y prepared s a t u r a t e d  f e r r o u s t h i o c y a n a t e s o l u t i o n was p i p e t t e d i n t o t h e removable ; t r a p , which was then plugged  and allowed t o warm up.  A time of 10 minutes was allowed f o r c o l o u r development ( f e r r i c t h i o c y a n a t e ) .  Absorbance of t h i s s o l u t i o n was  measured on a Bausch and Lomb Spectro 20 spectrophotometer 515 m/uo . two  at  Measurements were r e l i a b l e i n t h i s instrument t o about  significant  f i g u r e s f o r absorbance v a l u e s of l e s s than 0.4.  If the s o l u t i o n was t o o c o n c e n t r a t e d , d i l u t i o n t o a known volume w i t h absolute methanol was made b e f o r e absorbance v a l u e s were  42 taken. C a l i b r a t i o n w i t h known c o n c e n t r a t i o n s of hydrogen peroxide gave the f o l l o w i n g r e s u l t : C o n c e n t r a t i o n of peroxide =2.23x10 where A=  A moles/1  absorbance at 515 mju. . The t o t a l amount of peroxides were c a l c u l a t e d from the  absorbance, the above e x p r e s s i o n , and the t o t a l volume. q u a n t i t y of p e r o x i d e s as a percent of i n i t i a l 2-butenes  The was  c a l c u l a t e d from the amount of 2-butenes trapped which i n t u r n depended on the absolute measurement of peak areas from the chromatographic  flame  i o n i z a t i o n detector.  Since the  s e n s i t i v i t y of the flame i o n i z a t i o n d e t e c t o r was  gas  absolute  not very r e p r o -  d u c i b l e , the r e s u l t s f o r t h i s q u a n t i t y were s c a t t e r e d . (v)  Procedure The  f l o w r a t e was u n i t was NO was was  flow r e a c t o r was admitted  t u r n e d on<  evacuated.  i n t o the system.  N i t r o g e n at a d e s i r e d  The microwave d i s c h a r g e  When steady s t a t e c o n d i t i o n s were e s t a b l i s h e d ,  t i t r a t e d i n t o the system u n t i l the glow (due t o excess  just extinct.  i n t o the system.  A d e s i r e d f l o w r a t e of 2-butene was The p r e s s u r e of the system was  NO)  admitted  measured on the  MacLeod gauge. L i q u i d n i t r o g e n i n a Dewar f l a s k was main U-trap f o r a measured d u r a t i o n .  p l a c e d around the  T h i s t r a p was  then  from the flow system by t u r n i n g the a p p r o p r i a t e stopcocks allowed t o warm up. t e d gas sampling  isolated and  I t s contents were expanded i n t o the evacua-  b u r e t t e shown i n F i g . 8.  A gas  chromatographic  43 a n a l y s i s was made and peak areas were m e a s u r e d . peroxide  In the case of  a n a l y s i s , the contents were t r a n s f e r r e d t o a removable  t r a p , as d e s c r i b e d under the s e c t i o n on peroxide  analysis.  (vi) C a l c u l a t i o n s C a l c u l a t i o n s of c o n c e n t r a t i o n and l i n e a r flow v e l o c i t y were based on the p e r f e c t gas law: Concentration = £ = — V RT = 5 . 4 2 x 1 0 ^ moles/1 at 23°C where p= p a r t i a l p r e s s u r e of the compound i n q u e s t i o n , i n mm  Hg.  L i n e a r v e l o c i t y = Y. = ET 2 A A P = 1.36xl0  2  n  P  cm/sec at 23°C  where n i s t h e t o t a l f l o w r a t e i n m i l l i m o l e s / m i n , P i s t h e t o t a l pressure i n mm,  and A i s t h e c r o s s - s e c t i o n area of t h e flow  r e a c t o r i n cm . 2  R e s u l t s were u s u a l l y expressed  i n two groups:  a. P l o t s of l o g ( A %) against l o g ( 2 - b u t e n e ) i n i t i a l ' as condensed i n Appendices I I I and VI, where A % was the r e l a t i v e amount of product w i t h r e s p e c t t o the i n i t i a l 2-butene, expressed  as %.  For these  Slope = n - 1, where n i s the r e a c t i o n order  plots, with  r e s p e c t t o 2-butene. b. P l o t s of l o g ( ^ - % ) against l o g (0) i n i t i a l ' i n Appendices II and V.  a  s  condensed  The slope equals the r e a c t i o n  order w i t h r e s p e c t t o t h e 0-atoms.  44 3.  Experimental R e s u l t s (i)  Products T a b l e 5 shows a t y p i c a l example of experimental c o n d i -  t i o n s and r e s u l t s o b t a i n e d from a run. s i s of the: hydrocarbon  Table 6 shows an analy-  fraction for several preliminary experi-  ments . Table  5.  T y p i c a l experimental c o n d i t i o n s and r e s u l t s . Run No. Nitrogen flowrate 0-atom flowrate=NO f l o w r a t e trans-2-butene f l o w r a t e 0 as i m p u r i t y i n N (0.044%) T o t a l pressure Linear v e l o c i t y (0)i (trans-2-butene)± (0)ixlOO/(trans-2-butene)i (0 ) xl00/(trans-2-butene) 2  2  2  i  ±  A n a l y s i s by 10 f t DNP C a r r i e r gas: helium. Flowrate: 73 cc/min.  118 Mmole/min 160 7 /xmole/min 2. ju.mole/min 40 0 .070 j*.mole/min 0 .23 mm 120 cm/sec 1. 7 x 1 0 atoms/1 2. 5x10-6 moles/1 6. 8 0 . 17 - 7  column. at 58.4°±0.5°C. P r e s s u r e : 5 p . s . i . g.  Compound Methane, ethane ( m a i n l y ) , ethylene Propane Isobutane trans-2-butene  A  0 .813 1..36 1 .14 -3 .98  Y  4.2 Acetaldehyde 6.0 Propanal cis-2,3-butene oxide Acetone trans-2,3-butene oxide) Isobutanal ) Butanone-2 Biacetyl 33 X8 cis-trans Isomerization A  x  x  3  0 0 0 0 0  .137 .046 .096 .047 .034  0 0 0 0 0  .136 .137 .0095 .0076 .016  -  45 Table 5.  (Continued)  T o t a l peroxide T o t a l oxygenated product T o t a l hydrocarbons  0.307 1.23 3.31  Table 6. A n a l y s i s of the hydrocarbon f r a c t i o n of Runs 18-20 by Perkin-Elmer J column at 23°C; c a r r i e r gas: helium; pressure: 8 p . s . i . g . : f l o w r a t e 125 cc/min; and by the HMPA column at 0°C; c a r r i e r gas: helium; pressure: 8 p . s . i . g . ; f l o w r a t e : 37 cc/min. Ratios w i t h r e s p e c t t o ethane i s g i v e n . Compound 18 Methane Ethane Ethylene Propane Isobutane n-Butane Isobutene  0 .0282 1 .00 0 .344 0 . 159 0 .647 0 .0208 0 .0575  +  +  +  Run 19 0 .0282 1 .00 0 .343 0 . 158 0 .655 0 .0175 0 .0393  20 0 .0282 1 .00 0 .344 0 . 159 0 .588 0 .0284 0 .0485  Average 0.0282 1.00 0.344 0 .158 0 .63 0 .022 0 .048  Some n-butane, isobutene and trans-2-butene were present as i m p u r i t i e s i n the cis-2-butene used.  ( i i ) Reaction  Order  D e t a i l s of the r e s u l t s of 0-atom r e a c t i o n s with c i s 2-butene i s condensed i n Appendix I, and those of 0-atom r e a c t i o n s with trans-2-butene  i n Appendix IV.  T a b l e 7 shows the order of r e a c t i o n with r e s p e c t t o c i s - and trans-2-butene  f o r the r e a c t a n t s and v a r i o u s products.  Table 8 shows the order of r e a c t i o n with r e s p e c t t o the 0-atom f o r the same r e a c t a n t s and p r o d u c t s . The p l o t s of l o g ( A % ) against l o g (cis-2-butene) f o r cis-2-butene,  low hydrocarbons  ±  and f o r propane condensed  46 Table 7. Order of r e a c t i o n with r e s p e c t t o 2-Butene.  Reactant product  or  -5.5  (Butene) >  10  (Butene)± <  ic" -  i  2-Butene  co  cis-2-Butene  5  5  0 .71  +  0 .08  -0 .74  +  0 .36  2  io~ -5 0 .99 24 10~ 5 0 .31 X (Butene) , > 10-5.5 0 .89 Propane (Butene). < 10 -5.5 -0 .48 I -5.5 Isobutane (Butene)^ > 0 .96 ,  trans-2-Butene  0 .35  +  0 .09 .  0 .24  ±  0 .22  0 . 14  ±  0 . 10  0 .26  ±  0 ., 11  0 .48  ±  0 ,. 11  0 .40  +  0 . 15  ±  0 . 11 0 .25  ±  0 . 10  +  0 .34  +  0 . 13  -0 .44  ±  0 . 19  0 .67  ±  0 .08  0 .63  +  0 .07  0 .36  ±  0,. 15  -0 .07  +  0 .13  0 .36  +  0..09  Acetone  0 .47  ±  0 .07  0 .47  +  0 ., 11  trans-oxide  0 . 16  +  0 . 15  0 .53  ±  0 . 14  Isobutanal  0 .90  +  0 .08  0 .45  +  0 .20 ,  Methylethylketone  0 .80  ±  0 .09  0 .45  +  0 . 16  -0 .03  +  0 .50  0 . 11  0 .53  ±  0 . 16  . 15  0 .58  ±  0..23  CH , C H , 4  C  2  6  H  ( B u t a n e ) ,>.•; (Butene). <  5  ±  5,  ±  10  x  1  4.2  Acetaldehyde x  ±  6. 2  Propanal cis-butene-2,3-oxide  Biacetyl x  55  0 .60  ±  x  38  0 .28  + 0  c i s - t r a n s Isom.  1  47  T a b l e 8. Order of r e a c t i o n w i t h r e s p e c t t o O-atom —7  Reactant product  0  for  ( O ) i < 10  gm-atom/1, a l l orders are 0.  for  ( 0 ) > 10~ '° gm-atom/1: 7  i  or  „ „ , cis-2-Butene  ^ „ „ ^ trans-2-Butene  0 ..41 ± 0, .07  0 .15 + 0.06  0. .31 + 0. .08  0 .22 + 0.07  Propane  0 ..22 ± 0. .08  0 .027  Isobutane  0 ..98  0 .12 ±  0.06  2 .23 ±  0.22  2-butene C H , 2  4  C Hg, C H 2  4  0 . 17  4.2  x  0.09  ±  Acetaldehyde  0 ,.25  Propanal  0 ..96 ± 0 ., 13  0 .54  cis-butene-2,3-oxide  0 .33 ± 0 . 15  0 .36 + 0.07  Acetone  0 .92 + 0 .21  0 .65 ±  trans-butene-2,3-oxide  0, .27 ± 0 .25  0 .065 ±  Isobutanal  0 .42 + 0 . 14  0 .19 ±  Methylethyl x  ketone  0 ., 14  0 .59 ± 0 .08  -0 .0094 ±  0.08  ±0.06  0.06 0.09 0.08  -0 .11 ± 0.07  35  1 . 15 ± 0 .21  0 .65 ±  0.12  38  1 .06 ± 0 .22  0 .40 ±  0.13  X  c i s - t r a n s Isom.  t  Peroxide  1  co  0 .50 ±  2  0.12  48 i n Appendix I I I show a d e f i n i t e change i n s l o p e , t h a t i s , a change i n the order of dependence on change appears 10  -5 5 ' mole/1.  This  t o occur around a ( c i s - 2 - b u t e n e ) value of i  Trans-2-butene r e a c t i o n s were c a r r i e d out at -5  5  c o n c e n t r a t i o n s l e s s than 10 order was  (cis-2-butene).  mole/1, thus no change i n the  observed. Only a few experiments  t r a n s i s o m e r i z a t i o n was  studied.  were made i n which the c i s Thus t h e r e were not enough  data t o make a p l o t f o r the accurate d e t e r m i n a t i o n of the order of  dependence or c o n c e n t r a t i o n s of the r e a c t a n t s .  a v a i l a b l e data shows t h a t the geometric first  However,  i s o m e r i z a t i o n was  order with r e s p e c t t o eaah of the cis-2-butene and  the  0-atom. There was  too much s c a t t e r i n g among the r e s u l t s of  t o t a l peroxide a n a l y s i s t o g i v e any reasonable of  determination  the order of dependence on each r e a c t a n t . Fig.  14 shows a p l o t between i n i t i a l 0-atom t o c i s -  2-butene r a t i o against the percent of r e a c t i o n and the percent of  oxygenated p r o d u c t s .  trans-2-butene. only 1/7  F i g . 15 shows a s i m i l a r p l o t f o r  From these two  figures, i t i s clear that  of the oxygen atoms l e d to r e a c t i o n (assuming  each r e a c t i n g 0-atom gave r i s e t o one product molecule) 1  of the r e a c t i o n s gave oxygenated products.  a l l the 0-atoms accountable  oxygenated products, but the amount of hydrocarbon was  and  Only when the  i n i t i a l butene c o n c e n t r a t i o n s became about 70 times the 0-atom c o n c e n t r a t i o n was  that  initial  i n the  products  twice t h a t of oxygenated products as under other c o n d i t i o n s .  Fig.  •2  14.  T o t a l and ©xygenated products from cis-2-Butene.  h  (tO^j/ccis-a-ButeneJi ) x 100  &l  30  Fig.  15.  T o t a l and oxygenated  products from  ( VCtrans-2-Butene3 - ) x 1 0 0 Co  |  trans-2-Butene.  4.  Discussion The  f a c t t h a t the r a t e of 2-butene consumption i s t h r e e  times t h a t of the p r o d u c t i o n of oxygenated products, found i n t h i s study, s a t i s f a c t o r i l y e x p l a i n s the d i f f e r e n c e i n the absolute r a t e measurements by E l i a s being 1 . 3 x l 0 ly.  The  1 0  64  and by Cvetanovic  1 mole~ sec~ 1  1  and 3 . 9 x l 0  system used by E l i a s was  9  58  o , t h e i r v a l u e s at 25 C  1 mole~ sec~ respective1  1  very s i m i l a r t o the present  and the consumption of the o l e f i n i s mainly not due t o the r e a c t i o n w i t h the O-atom.  direct  Subject t o the accuracy of the value  of the r a t e constant of the 0 + N0  9  -1  1 mole  r e a c t i o n by Ford and Endow" ', 1  2  and the value of the r e a c t i o n 0 + 0 the value of 3.9x10  one  + M by Benson and Axworthy? , 0  2  I  sec"  f o r the r a t e constant of the 58 r e a c t i o n O + cis-2-butene o b t a i n e d by Cvetanovic s h o u l d be 64 1  c l o s e r t o the t r u e value than the value o b t a i n e d by  Elias  T h i s e x p l a n a t i o n i s supported by the f a c t t h a t when the i n i t i a l o l e f i n c o n c e n t r a t i o n i s about 70 times t h a t of the 0-atoms, a l l the 0-atoms are accountable found i n the present i n v e s t i g a t i o n .  as oxygenated products,  In the system used  by  58 Cvetanovic  , o l e f i n was  always i n a l a r g e excess and at a high  p r e s s u r e while the 0-atoms were generated by slow p h o t o l y s i s of N 0. 2  Since c o l l i s i o n a l d e a c t i v a t i o n should be f a i r l y  complete  i n such a system, the measurement of oxygenated products be a c l o s e measurement of the O + butene r e a c t i o n . 58 59 r a t e c o n s t a n t s obtained by C v e t a n o v i c  '  The  should be  should relative  reasonably  accurate. If the 0-atom a d d i t i o n t o 2-butenes i s t r e a t e d as an 72 e q u i l i b r i u m process i n a s i m i l a r way  as Benson et a l  treated  the i o d i n e atom a d d i t i o n t o cis-2-butene, an e q u i l i b r i u m constant  52 can be e s t i m a t e d f o r the r e a c t i o n -  O + W  i ^ 44  k  from the heat of r e a c t i o n o b s e r v a t i o n of c i s - t r a n s indicates iodine  that  \  3  r  /  (43)-(44)  and the change i n entropy. isomerization  The  i n the present study  the O + c i s - 2 - b u t e n e system i s s i m i l a r t o the  atom analogue,  and t h a t  t h i s approach  is justified.  Table 9, shows the data f o r t h i s e s t i m a t i o n . Table 9. Thermodynamic data f o r the c a l c u l a t i o n of K  Species  43,44'  S°, e.u.  H ° , kcal/mole  0-atom  38.5  a  59.2  a  cis-2-Butene  71.9  a  -1.7  a  trans-2-Butene  70.9  a  80.4  o-  r-2.7  b  cc  30  AS° = -30.0  a  a  A H ° = -28  C  From Ref. 75, p.662. C a l c u l a t i o n based on Ref. 72 by t a k i n g as model:  3-methylpentene-l  S° ( b i r a d i c a l ) = S° (3-methylpentene-l) + R In ' (symmetry; of 3-methylpentene-l) + R In q ( e l e c t r o n i c p a r t i t i o n f u n c t i o n ) - R In ( b i r a d i c a l ) - 1.5 ( f o r two e x t r a H-atoms) = 79.7 + R In 3 - 1.5 = 80.4 e.u. C  AH° =  D(ir)( 3^C---cC CH  W = 56  7 2  - 84  CH3  )  - D(C-O)  H 7 5  = -28 kcal/mole.  53 Thus  logK = =  °_ 2.3R  A  S  A  -30.0  , ° where . T = 298 —K o_ 2.3RT  H  D  28000  +  2 . 3R -6.60 log  2.3RT +  2  28000 8  0  0  where K i s i n a t m  0  2.3RT  K = l o g (RT) - (6.60 = -4.47 + A  A  n  27000  1  ) + 2.3RT 0  0  0  2  7  0  0  - 1  0  where K i s i n  2.3RT 1  m  o  l  e  a  t  2  5  .  °  C  2.3RT The  r a t e constant f o r the u n i m o l e c u l a r decomposition of  the s e c - b u t y l i o d i d e r a d i c a l  \-(  •  \=/  + i  (  -  ; 3 7 )  I  72 has been estimated t o be k  3 7  = 10  i -  1 3  2 0 0  0  Since the C-I bond energy  °/ -3RT  - l .  2  s  e  c  i s about 57.4 kcal/mole  value i s about 84 kcal/mole,  the a c t i v a t i o n energy  (44) s h o u l d have an a c t i v a t i o n energy  and the C-0 for reaction  of about 29 kcal/mole.  The p r e - e x p o n e n t i a l f a c t o r s f o r r e a c t i o n s (44) and (-37) s h o u l d be approximately k If  then  the same.  4 4  = 10  Thus k ^ can be estimated t o be lO- 9° /2.3RT  1 3  2  00  s  e  c  - l .  i t i s assumed t h a t  k  4 3  = k 4K43 44 4  - IO ' 8  5  i 0  2 0 0  °/ - RT ! ^ie-lsec2  3  1  which i s i n good agreement with the experimental value of  54 k  4 3  = 7.15xl0  9 e  -  3  6  0  /  R  T  1 mc-le^sec  .  - 1  :\  (from Cvetanovic's value**® of 3 . 9 x l 0  1  9  at 25°C and E l i a s ' s a c t i v a t i o n e n e r g y "  mole"^sec~  1  of  4  360 c a l / m o l e ) . C o n s i d e r i n g the roughness of the e s t i m a t i o n , t h i s agreement i s remarkable. would account  An e r r o r of about  f o r the d i f f e r e n c e  6 e.u.  in  4S°  i n the frequency f a c t o r .  e s t i m a t i o n s are good t o , at most, + 2 kcal/mole  and the  AH  agree-  ment i n estimated and experimental v a l u e s of the a c t i v a t i o n energy  i s good indeed.  Moreover, the agreement between estima-  t e d and experimental v a l u e s of k^g shows the v a l i d i t y of the p o s t u l a t e d path of the i n i t i a l  r e a c t i o n and of the probable  b i r a d i c a l intermediate. The c o l l i s i o n frequency, z, at 25°C between 0-atoms  -fi ^ and 2-butenes at i n i t i a l 0-atom c o n c e n t r a t i o n s of about mole/1 and i n i t i a l  2-butene c o n c e n t r a t i o n s of about  10 "  10~°0  moles/1  '.. (both i n the middle of the experimental range) can be shown t o be  ( °-2-Butene=5-88 . o - = l . 3 2 8 . *b-Bu=3.46°,) 19 l l z = 2.9x10 molecules cc~- sec~ -2 l I = 4.9x10 moles l - ^ s e c . 76  75  Q  L  J  - 1  If  the r e a c t i o n frequency i s c a l c u l a t e d from the  frequency f a c t o r  (A) of the experimental value of k ^  calculated  3  above, i t can be shown t h a t R e a c t i o n frequency = A ( 2 - b u t e n e ) ( 0 ) ^ i  = 7.15xl0  9  xlO  -  6  0  xlO  -  6  5  moles l " .-1 sec  = 2.3xl0Thus the s t e r i c f a c t o r  3  moles l s e c " * , - 1  (P) f o r t h i s r e a c t i o n i s about  1  1/22.  1  55 The  c o n t r o l l i n g f a c t o r s i n the r a t e of r e a c t i o n are t h e r e f o r e  both the a c t i v a t i o n energy has p o s t u l a t e d  5 8 , 5 9  and the frequency f a c t o r .  Cvetanovic  t h a t the c o n t r o l l i n g f a c t o r i n the  relative  r a t e of r e a c t i o n between 0-atoms and v a r i o u s o l e f i n s i s the d i f f e r e n c e i n a c t i v a t i o n energy A factor.  and not the d i f f e r e n c e i n the  I t f o l l o w s t h a t the s t e r i c f a c t o r s f o r O-atom 64  r e a c t i o n s with o l e f i n s must be approximately! e q u a l .  Elias  has argued that the c o n t r o l l i n g f a c t o r should i n c l u d e the d i f f e r e n c e i n the A f a c t o r . Cvetanovic's v a l u e  5 9  f o r the a c t i v a t i o n energy  0 + ethylene r e a c t i o n i s 1 kcal/mole  higher than Elias,'s value  If the same i s t r u e f o r the 0 + cis-2-butene r e a c t i o n , value would be 1.36 k^3  kcal/mole.  of the 64  T h i s , i n combination  Cvetanovic'  with h i s  value at 25°C, would give r i s e t o a s t e r i c f a c t o r of \.  Thus i t i s c l e a r t h a t the c o n t r o l l i n g f a c t o r s f o r the 0 + c i s - 2 butene r e a c t i o n s must i n c l u d e the s t e r i c  factor.  A p l a u s i b l e e x p l a n a t i o n f o r the unaccountable  disap;-?  pearance of 0-atoms can be made by p o s t u l a t i n g the f o r m a t i o n of an  O-atom: butene-2 complex.  A c h a r g e - t r a n s f e r complex between 77 0- atoms and o l e f i n s has been c o n s i d e r e d p o s s i b l e . IT-complexes 60 between 0-atoms and o l e f i n s , between i o d i n e atoms and c i s - 2 71 78 butene and between ozone and o l e f i n s have been p o s t u l a t e d .  71  In e x p l a i n i n g h i s k i n e t i c data, Cvetanovic has p o s t u l a t e d ' that the I - atom : cis-2-butene complex would c o l l i d e with 1- atom t o form I  2  and  another  cis-2-butene:  I: I cis-2-butene + cis-2-Butene+ I  I + cis-2-butene ». ^. I: cis-2-butene 2  ($6) (45)  56 It appears t h a t a s i m i l a r s i t u a t i o n e x i s t s i n the present  study of the r e a c t i o n between 0-atoms and 2-butenes: 0 +  V  w  \ J  /  (46)  V=/  (47)  0 0 +  \ J  >-  ==  0  2  +  O An a l t e r n a t i v e p o s s i b i l i t y i n v o l v e s a 4-centre O +  scheme:  W  (43) o'  O +  V Y  ^  o'  ^ 0  + \J  (48)  among products i s the evidence t h a t  oxygen was p r e s e n t .  The q u a n t i t y of  i n d i c a t e d t h a t the amount of molecular that amount present  2  6-6  The presence of peroxides molecular  W  as i m p u r i t y  peroxides  oxygen was more than  (some of the i m p u r i t y  oxygen  would have been d i s s o c i a t e d by the microwave d i s c h a r g e ) . was a l s o more than the homogeneous and s u r f a c e c o u l d produce.  It  recombinations  Thus the l a r g e q u a n t i t y of molecular  oxygen  must a r i s e from o l e f i n c a t a l y z e d recombination of 0-atoms through the complex scheme of r e a c t i o n s c e n t r e scheme of r e a c t i o n s (43)-(48).  (46)-(47) or the 4These p o s t u l a t e s  also  e x p l a i n the unaccountable disappearance of 0-atoms observed by 54 63 67 other workers  a n <  j d i s c u s s e d under S e c t i o n 1 of t h i s  chapter. At t h i s p o i n t , i t i s p o s s i b l e t o p o s t u a l t e a mechanism t o e x p l a i n the formation  of products.  The i n t i a l 0-atom a t t a c k  has been shown above t o form a b i r a d i c a l :  57 O +  \=/  ^  + 28 k c a l  (43)  ok Energies  ~^xlO  4 3  of the bonds attached  a~fl.60§/RT  a t  1  t o the t e r t i a r y carbon atom.are are bond d i s s o c i a t i o n 2.  n e a r l y equal as shown (the numbers energies  mole-^ec" .  ±  i n kcal/mole) H C  "3 ^  H  I _80_ I  ^  C  H  3  6" Thus the b i r a d i c a l c o u l d decompose W  +  i n one of t h r e e ^ a y s :  o  ^  (44) _ 1 3 -29000/RT 1 0  *-  o-  e  CH3CHCHO + CH  a-  g  e  c  - l (49)  3  CH CH: + CH CHO 3  (50)  3  C i s - t r a n s i s o m e r i z a t i o n occurs as a r e s u l t of the r o t a t i o n of the centre C-C bond i n the b i r a d i c a l i n a manner s i m i l a r t o the iodine-atom c a t a l y z e d c i s - t r a n s i s o m e r i z a t i o n of 2-butenes 7 9  ( r e a c t i o n (38))  and of the s c i s s i o n of the C-0 bond: rt  k  r~/ n>-  5 i  (51) °-  —J^L. k  Cis-trans isomerisation  53  10 ' 11  /=/  2 e  -  3  3  0  0  /  R  T  sec"  + ©  1  T  i  (52)-(53)  /  i s very u n l i k e l y t o a r i s e as a r e s u l t  of hydrogen a b s t r a c t i o n of the b u t e n y l r a d i c a l  58 (CH CH=CHCH 3  2  —  CH CH-CH=CH ). 3  McNesby and Gordon have s h o w n  2  that t h i s r e s o n a n c e - s t a b i l i s e d c i e n t hydrogen  butenyl  a b s t r a c t i o n only  r a d i c a l undergoes  at about 500°C.  improbable t h a t the c i s - t r a n s i s o m e r i s a t i o n  49  effie:'.  I t i s a l s o very  o f 2-butenes  is a  r e s u l t of methyl r a d i c a l a d d i t i o n t o the 2-butene and the subsequent displacement of another methyl r a d i c a l from the parent 2butene.  Trotman-Dickenson  and S t e a c i e ^  addition reaction i s insignificant  have shown that  0  this  at room temperature. C i s -  and trans-2,3-butene oxides are ^prob/ably:idexiiVed c£»oatt'1ihiexd:.r'.g !  liajg ^biisadical- "by r i n g c l o s u r e :  H. y—^ Isobutanal  V  ^ M  »  y^/  + 84 k c a l  (54)  + 84 k c a l  (55)  i s thought t o be formed by the r e a c t i o n o f the two  r a d i c a l s formed i n r e a c t i o n (32): CH„ CH3CHCHO  + CH  3  -  CHCHO CH  (56)  3  Propanal may be formed by the a b s t r a c t i o n of hydrogen by t h e i s o p r o p i o n y l r a d i c a l produced i n r e a c t i o n (49): CH3CHCHO + CH3CHO or:.  CH3CHCHO + CH CH=CHCH3 3  a-  CH CH CHO + C H 3 C O 3  (57)  2  CH CH CHO 3  2  + CH CH=CHCH -s-s-CH CHCH=CH 3  2  (R)  3  (R>  2  :  The f o r m a t i o n o f butanone-2 i s probably due t o the m i g r a t i o n of a hydrogen biradical:  atom from one t e r t i a r y p o s i t i o n t o another i n the  H  5  9  B i a c e t y l i s normally formed when two a c e t y l r a d i c a l s produced i n r e a c t i o n (57) combine: 2 CHoCO  CHo-C-C-CHo (60) i| || o o The a c e t y l r a d i c a l can a b s t r a c t a hydrogen from 2-butene: C H C 0 + 2-butene  a-  3  + R  CH3CHO  (61)  CO i s p r o b a b l y formed when t h i s r a d i c a l decomposes: CH C0  »• C H  3  + CO  3  (62)  but appeared mainly as C 0 due t o 2  CO +  0  *~ C 0  (63)  2  Acetone i s formed when a methyl r a d i c a l r e a c t s w i t h an a c e t y l radical: CHj  + CH C0  a- CH -C-CH  3  3  (64)  3  o E t h y l e n e c o u l d be formed when t h e e t h y l i d e n e r a d i c a l produced in reaction  (50) i s o m e r i z e s :  CH CH: 3  *• CgH^  M  > C H 2  (65)  4  79 Frey  has found t h a t , i n c o n t r a s t t o the p r o p e r t i e s of t h e  methylene r a d i c a l , e t h y l i d e n e a d d i t i o n t o c i s - 2 - b u t e n e i s insignificant  compared w i t h i t s own i s o m e r i z a t i o n .  Kibby and  80 Kistiakowsky  have shown t h a t c i s - 2 - b u t e n e a c t s as a t h i r d  body i n ethylidene i s o m e r i z a t i o n . Ethane i s formed when two methyl r a d i c a l s 2 CH  3  *- C H 2  combine: (66)  g  Trotman-Dickenson and Steacie ® 7  have found t h a t , at  60 room temperature, the r e a c t i o n between methyl r a d i c a l s and o<-hydrogen a b s t r a c t i o n and t h a t  butenes mainly i n v o l v e s is  insignificant. CH  3  2-  addition  Thus  + 2-butene  CH  The methyl r a d i c a l can a l s o a b s t r a c t  + R  4  (67)  a hydrogen from  acetalde-  hyde: CH  + CH CH0  CH  3  3  Since methane was  4  + CH3CO  produced i n v e r y s m a l l  (68)  quantities,  reactions  (67) and (68) are unimportant. Other hydrocarbons are probably formed through the following  reactions:CRgCH: + CH CH3CHCH3 CH3CHCH3  CHgCHCHg  3  + 2-butene + CH  *- C H C H C H CH ^ 3  s~  3  2  3  + R  (70)  3  "^CHCH  CH CHj + R  (69)  (71)  3  3  pentenes  (72) 53  C v e t a n o v i c at f i r s t  postulated  the i n i t i a l  reaction  between 0-atoms and 2-butenes t o form a epoxide, 0  +  \=/  &-  and other a d d i t i o n products t o form on the  isomerization  ( i n v o l v i n g i n t e r n a l group m i g r a t i o n ) of t h i s epoxide.  Later °'^ ,  he m o d i f i e d  attack  his postulate  such t h a t the i n i t i a l 0-atom  5  on 2-butene would form a b i r a d i c a l 0 +  w  >  v  o-  According t o t h i s l a t e r p o s t u l a t e ,  s c i s s i o n of C-C  bond would  7  61 occur o n l y a f t e r t h e b i r a d i c a l forms a hot epoxide molecule:  T h i s step would i n v o l v e simultaneous breakage of a C-C bond and a C-0 bond and would most probably be u n l i k e l y .  Moreover, t h e  only a l k y l r a d i c a l produced would be t h e methyl r a d i c a l . f o r m a t i o n of a r e l a t i v e l y  The  l a r g e amount of ethylene would be  d i f f i c u l t t o e x p l a i n on t h i s h y p o t h e s i s .  T h i s mechanism a l s o  does not p o s t u l a t e t h e s c i s s i o n of the C-0 bond i n t h e b i r a d i c a l , which i s c l e a r l y i n d i c a t e d i n t h e present study, e s p e c i a l l y by the o b s e r v a t i o n of c i s - t r a n s i s o m e r i z a t i o n and by t h e f a c t  that  the i n i t i a l O-atom a d d i t i o n can be t r e a t e d as an e q u i l i b r i u m . A steady s t a t e treatment of t h e p r e s e n t l y proposed mechanism would g i v e the f o l l o w i n g d(CH ) 3  = 56 66 < k  k  C H  3)  4  result:-  [(2k  +  5 6  k  6 7  k  6 9  -k  5 8  k  6 6  k  6 9  )(B)  dt ( 56 68 69  +  k  k  k  3  +  +[ 4 3 5 0 5 6 6 9 k  k  k  • +  k  k  (0)(B)+(2k  5 8 6 6 6 5 > <> k  k  B  k  4 3  k  6 7  k  6 5  +2k  5 8  k  6 7  k  ( 6 1 6 7 6 9 5 8 6 8 6 9 > <> <  +  2 k  k  + C 56 62 65 61 66 65 Jk  5 6  6 9  £k  k  k  4 9  k  k  + k  5 6  k  6 5  k  k  + k  4 3  k  )(  k  A  c  A  + k  ) + k  k  k  61 68 69 k  k  k 6 9  B  +  ( A c A ) 2  A c A )  ] £^3^ (  43 50 58 69 k  k  ^  k  43 50 61 69 " 43 49 61 69 ^(0) (B)(AcA) + 5 6 6 9 5k 21 k k  k  k  k  k  k  k  k  k  62 , 58 69,_ k  ^ 61 69  k  k  %  ( B ) 5  k  S  + (2k  +  k  +  k  6 1  k  6 7  that  4 4  + k^g + kgQ  (CH )  k  k  k  k  A c A  )  k  k  ( k  + kgg-  disappearance of 2-butene  4 3  k  (B)  The  1 / 3 _ 1  .  k 6 5  = 0  The r a t e of  5 8  50 70  (B)  k  [  71< 2) 70(B) C H  k  k 5 8 +  °  L  & i  ^  + k  ll  U C A >  k ^ k ( B ) +k (CH )J 6  6 1  64  57  3  l a s t term i n v o l v e s the methyl r a d i c a l a b s t r a c t i o n of  hydrogen from 2-butene t o form methane.  S i n c e methane has  been found o n l y i n very s m a l l amounts, t h i s  l a s t term i s  unimportant. Since  k  ^  f i 2  »  k  6].(B) k (CH ) 6 4  3  the l a s t term i n s i d e the b r a c k e t s k (AcA)  k  4 4  k  62  + k  6l( > B  + k  64<  J  49+ 50+ 62 k  k (CH )(B) 6 7  (B)  k  .  3  6 5  ° (B)2(0) Ik  B  k k  k (CH )+k (B)+k (AcA) +  k 4 3 k 5  ( )(AcA)  +k  ^ 5 6  +  ("  k  k  i s given by  44+ 49+ 50 62 I k  6 7  From thesabove e q u a t i o n i t i s c l e a r  (0)(B)  H  CH  ( 0 )  k  AcA f o r acetaldehyde and  k  dt  6 5  < 3>  k  5 8  )(B)(AcA)  k 6 8  43 61 65 50 * 49>  1  d(B) _ k  k  ]  2  i s a f u n c t i o n of ( O ) ^ " ,  3  2  (AcA) + 2 k  k  + 58  6 5  61 68 65(  where B stands f o r 2-butene, £ k=k  k  +  C H  3>  k  4 4  62  (AcA)  3  63 k  Since  »  5 g  ^44 (AcA) k  [k  + f44  5 g  k  ( A c A )  62  ]  _  k  5 g  62  Since both r e a c t i o n s (6-1) and (58) i n v o l v e a b s t r a c t i o n of hydrogen b y j t h e i s o p r o p i o n y r a d i c a l , kgg and k^^yshould be of the same order of magnitude, but (B) » the term kgj.(AcA)  Therefore  i n the denominator may be dropped.  d(B)  k  dt  k44+k k5o+k 2 L 4 9  4 3  (AcA).  ( )(B)  k  0  r k  49+  + k  6  50  + k  Thus  50 70(B) k  62 - 7l(CH ) + k (B) k  7 0  3  k  k  9 58 k  4  56(CH ) + k 3  S i n c e (CH ) i s a f u n c t i o n o f ( O ) ^ , - 1  3  b e f o r e , the r a t e o f disappearance t h e r e f o r e a f u n c t i o n o f (0)  (B)  1 / 3 - 1  5 8  ]  ( ) B  found  of 2-butene, - ( 3 ) , i s d  0 1 0-1 ^ , (B) and i s i n q u a l i t a t i v e  agreement w i t h experimental v a l u e s found and given on pages 46-47.  I t i s a l s o apparent  t h a t the orders o f dependence with  respect t o each r e a c t a n t are f u n c t i o n s of the c o n c e n t r a t i o n s . It should be noted t h a t when a b s t r a c t i o n s are i n s i g n i f i c a n t and (CH ) i s s m a l l , as under high pressure c o n d i t i o n s 3  - ^ ^ i s a simple f u n c t i o n o f (0)(B), dt c o r r e c t l y assumed by C v e t a n o v i c . employed by C v e t a n o v i c , 5 8  d  B  5 8  The  r a t e of p r o d u c t i o n o f ethylene i s given by  d(ethylene)  _ k  dt and i s a f u n c t i o n o f ( 0 )  4 3  k  5 ( )  k  6 5  ( 0 ) (B)  k k +k (CH ) 6 5  0 _ 1  ,  (B)  6 9  0 - 1  3  ,  i n agreement with  64 experimental v a l u e s .  The r a t e s of p r o d u c t i o n of propane and  of carbon d i o x i d e are d(propane)  =  k  dt  k  2  k  k  5 ( )  k k  d(C0 ) dt  4 3  ? 0  6 g  k  7 0  ( 0 ) (B) (CH ) 3  ( B ) k (CH ) +  ? ±  3  43 49 61 62 63 k  k  k  k  k  6 5 +  ( 0 ) 2 ( B )  (  k  A  c  k k +k (B)+k (CH ) 6 2  6 1  6 4  3  6 9  A  (CH ) 3  )  k (CH )+k (B) + 5 6  3  5 8  k (AcA) c 1  and are i n agreement with experimental o b s e r v a t i o n s . In c o n c l u s i o n , the p r e s e n t l y proposed mechanism i n volving a.  the o l e f i n c a t a l y z e d recombination of 0-atoms through a 0:butene-2 complex or a 4-centre scheme; and  b.  the decomposition  of the i n i t i a l adduct,  a biradical,  i n t h r e e n e a r l y e q u a l l y probable ways can s a t i s f a c t o r i l y e x p l a i n the present experimental r e s u l t s and a l s o the o b s e r v a t i o n s of e a r l i e r i n v e s t i g a t i o n s by o t h e r s . Thus i t i s apparent t h a t the v a r i o u s mechanisms p o s t u l a t e d f o r the f o r m a t i o n of the observed r e a c t i o n products must be regarded as s a t i s f a c t o r y .  T h i s a l l the more so when the complexity of  the o v e r a l l r e a c t i o n processes are kept i n mind.  65 CHAPTER I I I THE 1.  OXIDATION OF 2-BUTENES BY MOLECULAR OXYGEN  Introduction A l a r g e number of papers on the subject of c a t a l y t i c  o x i d a t i o n of o l e f i n s are a v a i l a b l e  8 1  but only r e l a t i v e l y few 1-4 13  works are known on the homogeneous o x i d a t i o n of o l e f i n s  » »  21-23,41,44-46. In the case of the o x i d a t i o n of 2-butenes i n the gas phase, Dobrinskaya and Neiman-  s t u d i e d the c o o l flame o x i d a t i o n  at 290 mm Hg u s i n g equimolar mixtures of oxygen and t h e o l e f i n at 310°C. and  There was an i n d u c t i o n p e r i o d d u r i n g which  peroxides  aldehydes (claimed t o be acdtadehyde and crotonaldehyde)  accumulated a c c o r d i n g t o the expression: C  of the product and 0 was found t o  where C was t h e c o n c e n t r a t i o n be 7 . 2 8 x l 0 was  e"  1 0  2 0 0 0 0 / | l T  A e**  =  : sec' .  Only 1-2% of the i n i t i a l  1  2-butene  consumed d u r i n g the i n d u c t i o n p e r i o d a f t e r which a c o o l flame  commenced.  These authors e x p l a i n e d t h e i r o b s e r v a t i o n by propos-  i n g two o x i d a t i o n (a)  routes:  CH CH=GHCH '.+ 0 3  3  2  _ ^ CH CH-CHCH 3  ^ 2CH CH0  3  3  (73)  0—0 (b)  CH CH=CHCH 3  3  + 0  CH CH=CHCH 00H 3  2  2  —CHCH=CHCH 00H  (74)  2  ^ CH CH=CHCH0 + H 0 3  2  (75)  21  " i :>  B l u n d e l l and Skirrow  i n v e s t i g a t e d the same r e a c t i o n  at 289°C and 385°C, u s i n g 2-butene-oxygen mixtures of v a r i o u s r a t i o s and t o t a l pressure  of 40-90 mm Hg.  Crotonaldehyde was  not found by these authors i n c o n t r a s t t o the r e s u l t s of  66 Dobrinskaya  and Neiman.  R e a c t i o n products at 289°C were  peroxides, formaldehyde,  other aldehydes  (including  acetyl-  dehyde and a c r o l e i n ) , carbon monoxide and methane.  At 385°C,  carbon d i o x i d e , e t h y l e n e and propylene were a l s o found.  Results  and d i s c u s s i o n s i n t h i s study by B l u n d e l l and Skirrow r e v o l v e d around the t o t a l p r e s s u r e change, A P.  A f t e r an i n d u c t i o n  p e r i o d , t h e r e was a s m a l l decrease i n t o t a l p r e s s u r e and then a sudden l a r g e i n c r e a s e as shown i n F i g . 16. ^ f^ dt 1  was at i t s maximum and t h i s value,  At t h i s p o i n t ,  \ dt /max  , was u t i l i z e d  by these authors as a measure of t h e r a t e of r e a c t i o n . the maximum r a t e of oxygen consumption, #d AQ^x ^ /dAP\ ^ /max c o i n c i d e i n time with C ) , as shown i n F i g . 16. ^ ' max d  d  was  However, n o  ^.  t  t  There  a l s o no p r o p o r t i o n a l i t y between these two q u a n t i t i e s , as  g e n e r a l l y i s the case. No d i f f e r e n c e was found by these authors i n e i t h e r or the products formed between u s i n g t h e c i s - or t r a n s dt / max ' o /dAP\ forms of 2-butene as i n i t i a l r e a c t a n t . At 289 C, ( ,. ) \ /max appeared t o go through a maximum when e i t h e r butene p r e s s u r e or  (  iL£i!\  d  oxygen p r e s s u r e was i n c r e a s e d .  o /d ^ P \ At 385 C, ( • )  \  d t  t  increased  Anax  w i t h an i n c r e a s e i n oxygen p r e s s u r e but decreased with an i n c r e a s e i n butene p r e s s u r e .  At both temperatures,  the o v e r a l l  r i s e i n t o t a l p r e s s u r e , AP^ , i n c r e a s e d with an i n c r e a s e i n oxygen p r e s s u r e but decreased on an i n c r e a s e i n butene p r e s s u r e . Inert a d d i t i v e s such as n i t r o g e n and hydrogen had no e f f e c t on t h e course of the r e a c t i o n . dehyde reduced the i n d u c t i o n p e r i o d .  The a d d i t i o n of f o r m a l The a d d i t i o n of a c e t y l -  dehyde t o an amount equal t o t h e maximum q u a n t i t y produced  67  F i g . 16b.  Progress of r e a c t i o n at 385°C ( B l u n d e l l and S k i r r o w ) 2 1  68 e n t i r e l y eliminated, the i n d u c t i o n p e r i o d .  An i n c r e a s e i n s u r f a c e  area lengthened the i n d u c t i o n p e r i o d and decreased the values of both  f ^ ) /max d  v  d  p  and  .  t  These authors proposed the i n i t i a l r e a c t i o n step t o be:CH -CH=CH-CH 3  3  + 0  CH -CH=CH-CH ' + H 0  2  3  2  .J  CH -CH-CH=CH 3  (76)  2  2  though not r u l i n g out the p o s s i b i l i t y of the symmetrical  fission  of the c y c l i c peroxide, r e a c t i o n (73) d i s c u s s e d above, favoured by Dobrinskaya  and N e i m a n . 22  21  B l u n d e l l and Skirrow  c o n s i d e r e d the main products  t o be formed by t h e f o l l o w i n g p r o c e s s e s : CH -CH-CH=CH 3  2  —CH  3  CHO  + CH CH + OH  (17)  2  OOH (A)  CH =CHCHO + OH  + CH  2  The formation of t h e 1-hydroperoxide,  (18)  3  CH CH=CHCH OOH 3  2  (B), was  r u l e d out because crotonaldehyde was not found i n the r e a c t i o n p r o d u c t s . Chain branching was c o n s i d e r e d t o be the r e s u l t of the r e a c t i o n of acetaldehyde with oxygen. 23 N o r r i s h and P o r t e r 2-butenes i n both s t a t i c systems.  s t u d i e d t h e o x i d a t i o n of 1- and  (at 364°C) and flow (at 320-380°C)  The o x i d a t i o n of 2-butenes was s t u d i e d at t o t a l  p r e s s u r e s of 31-62 mm Hg i n mixtures of two p a r t s oxygen t o one o part 2-butene.  The pressure-time curve at 364 C was found t o be  s i m i l a r t o that shown i n F i g . 16b, o b t a i n e d by B l u n d e l l and Skirrow  2 1  at 385°C.  A s m a l l p r e s s u r e decrease was d e t e c t e d  s h o r t l y b e f o r e t h e end of the i n d u c t i o n p e r i o d .  Products were  analysed by gas chromatography and i d e n t i f i e d s o l e l y by t h e i r  69 r e l a t i v e r e t e n t i o n volumes.  Product  formation was  followed  s t a r t i n g s h o r t l y b e f o r e the end of the i n d u c t i o n p e r i o d . I n i t i a l products were found t o be acetaldehyde  and 23  a c r o l e i n , i n the r a t i o of 3 or 4 t o 1. t h e r e f o r e contended  N o r r i s h and P o r t e r  that the "crotonaldehyde" r e p o r t e d by  22 Dobrinskaya  and Neiman  was  probably a c r o l e i n i n r e a l i t y . 23  Major products found by N o r r i s h and P o r t e r p e r i o d were formaldehyde,  a f t e r the  acetaldehyde, propanal,  acrolein,  water, methanol, carbon monoxide and carbon d i o x i d e . aldehyde,  induction  Croton-  e t h a n o l , methane, e t h y l e n e , propylene, 1-butene, t r a n s -  2-butene (with cis-2-butene as i n i t i a l r e a c t a n t ) and hydrogen peroxide were found as minor p r o d u c t s .  Ethylene oxide  and  propylene oxide were found i n t r a c e s . These authors found no d i f f e r e n c e between u s i n g c i s or  trans-2-butene  as the i n i t i a l r e a c t a n t , i n agreement with 21  B l u n d e l l and Skirrow mediates  .  During the i n d u c t i o n p e r i o d , i n t e r -  were found t o accumulate 22  with Dobrinskaya f a c t o r 0 was  and Neiman  e x p o n e n t i a l l y , i n agreement  (see page 65).  The net branching  found t o be 0 - 0.0144P - 0.170  sec"  1  where P i s the t o t a l p r e s s u r e of mixtures i n the: r a t i o  (oxygen/  2-butene) = 2. 21 As i n the study of B l u n d e l l and Skirrow  (see page 6.6}  Norri s h and P r ct te iro n r proposed that the f o l l or w i en g of e x pp r ir oe n the maximum ro ea a t e , measured as the at re es ss su would t thetaken experimental o b s e rof v a tthe ions change,f iwas as a measure o: v e r a l l r a t e of o x i d a t i o n . 23  70 Rate  - k (0„)(2-Butene) 1 z  max  a  n  -  k (2-Butene) , z b  n  where a and b are c o n s t a n t s . These authors found t h a t i n e r t l i t t l e effect  gas ( n i t r o g e n ) had  on t h e maximum r e a c t i o n r a t e , which, however,  i n c r e a s e d with an i n c r e a s e i n r e a c t i o n v e s s e l diameter.  The  maximum r e a c t i o n r a t e was found t o be dependent on the a c e t a l dehyde c o n c e n t r a t i o n as f o l l o w s : Rate  max  = K(Acetaldehyde)P  - C  where P i s t h e t o t a l p r e s s u r e of mixtures  i n the r a t i o  (oxygen/2-butene) = 2. 23 N o r r i s h and P o r t e r  proposed  a complex mechanism i n  which t h e OH r a d i c a l was c o n s i d e r e d t o be t h e main c h a i n c a r r i e r . The  s m a l l p r e s s u r e drop s h o r t l y b e f o r e t h e end of the:.induct i o n  p e r i o d was a t t r i b u t e d t o the f o r m a t i o n of t h e c y c l i c  peroxide  CH3-CH-CH-CH3 0 — 0  first  proposed  by Dobrinskaya  and Neiman  22  .  N o r r i s h and P o r t e r  concluded t h a t acetaldehyde was the main degenerate agent. 0,  branching  The appearance of c o o l flames was e x p l a i n e d i n terms of  t h e net b r a n c h i n g f a c t o r f o r acetaldehyde, changing  p o s i t i v e t o negative as t h e temperature The  from  rose.  homogeneous l i q u i d phase o x i d a t i o n of 1-butene  and cis-2-butene, by B r i l l  23  among other lower o l e f i n s , has been s t u d i e d 82 o  and Barone  as the s o l v e n t .  at 120 C and under p r e s s u r e , with benzene  I n d u c t i o n p e r i o d s of a few minutes f o r c i s - 2 -  butene and about 45 minutes f o r 1-butene preceded a p p r e c i a b l e r e a c t i o n i n 50 mole % s o l u t i o n s .  Products are shown i n T a b l e 10.  T a b l e 10 O x i d a t i o n products o b t a i n e d by B r i l l  Product  Reactant cis-2-Butene +  1-Butene 18,,4 19 .4  Conversion % Epoxide  18.,6 48..2 (19,. 5 c i s 28.,7 t r a n s )  15,.9 10 . 1 7 .6  -,5 34. - .4 10.  3 .6 12 .5 1..5  -2..5  3.,9 1..7  Monoformate Diformate Acetaldehyde Propanal Methylethylketone Crotonaldehyde Acrolein Biacetyl Acetic acid A c r y l i c acid Propionic acid Butyric acid +  and Barone  -9 .9  6,.9 4,.6 6 .9  P r o d u c t q u a n t i t i e s are given i n terms of % of t o t a l product. The r e l a t i v e r a t e c o n s t a n t s , c a l c u l a t e d from the  maximum r a t e of oxygen a b s o r p t i o n and from t h e e x p r e s s i o n d(0 ) —fc—k  2 (olefin) ,  2  give  k  1-butene k  2-butene  =  1.2 4  2  These authors d i d not make much i n v e s t i g a t i o n i n t o the k i n e t i c s of the r e a c t i o n s beyond s t a t i n g that the o n l y reasonably adequate e m p i r i c a l r a t e c o n s t a n t s c o u l d be o b t a i n e d by assumi n g a t h i r d order dependence.  They a l s o s t a t e d that t h e d i f -  ference i n products between 1-butene and 2-butene was incompati b l e with t h e g e n e r a l l y c o n s i d e r e d i n i t i a t i o n step of the a b s t r a c t i o n of ot - hydrogen, because both 1-butene and  2-butene would give t h e same b u t e n y l r a d i c a l s i n resonance. CH CH-CH=CH 3  2  *  >. CH CH=CH-CH 3  and a l l products except those formed on f i r s t the  same.  2  a t t a c k should be  The f o r m a t i o n of epoxide was e x p l a i n e d as  CH CH=CHCH 00 3  2  + CH CH=CHCH 3  — i - * -  3  CH3CH-CHCH3  V  + CH CH=CHCH 0 3  2  (7.9)  A v e r y d e t a i l e d i n v e s t i g a t i o n of the n o n - c a t a l y t i c , l i q u i d phase o x i d a t i o n of 1-butene and c i s - and trans-2-butenes 83-86 has been made by Chauvel and h i s covworkers. Experiments were c a r r i e d out i n benzene s o l u t i o n s , o  a p r e s s u r e of 25 kg/cm .  at 65-140°C,  and under  I n d u c t i o n p e r i o d s of about 60 minutes o  were encountered when temperatures were below 135 C, n e c e s s i t a t i n g t h e use of i n i t i a t o r s .  Azodiisobutyronitrile  used below 90°C and a z o d i c y c l o h e x y l n i t r i l e the  temperature range 90-125°C.  (ADBN) was  (ADCN) was used i n  T h e i r r e s u l t s show that  hydroperoxides were primary p r o d u c t s .  T a b l e 11 shows the  r e s u l t s of experiments w i t h a mixture of 75% c i s - and 25% trans-2-butene. F i g s . 17 and 18 show t h e r e l a t i o n s h i p between oxygen absorbed and hydroperoxide produced as a f u n c t i o n of time f o r 1-butene and 2-butenes  respectively.  73 T a b l e 11 R e s u l t s of experiments u s i n g 75% c i s - and 25' trans-2-butene by Chauvel and h i s co-workers T°C  02 Absorbed  Progress  %  M x 3D'  65  0 .93 2 .41 4 .33 7 .17  0 . 10 0 .29 0 .52 0 .86  0.95 2.50 4.25 6.83  70  2 .25 4 .50 6 . 17 8 .75 10 .25 13 .83  0,.27 0 .54 0 .74 1 .05 1 .23 1 .66  2.42 4. 54 5.67 7.10 7 .98 9.50  80  6 .42 12 .5 18 .0 25 .0 36 .4  0 .77 1..50 2 .16 3 .00 4 .36  M x 10  2  ROOH  2  Epoxides  6.00 9.67 14.08 17 .0 20.9  M X 10  3  Acids  MxlO  2  Epoxides/  ROOH x 10  0 0,.33 2.,58 4..901  0 0 0 .79 , 2 .33  0 1. 33 6.,08 13.,9  1.,06 5,.67 7 .08 , 9,.00 12,.5 17 .5 ,  0 1 .58 2 .42 4,.58 4,.92 6 .33  4,,38 12,.5 12,,5 15,,3 16,.5 18,.4  6,.50 17 .8 , 27 .5 , 37,.5 51,,9  1,.58 5 .92 9 .50 21,.40 33 .75  10,.8 18,.4 19,.5 21,.0 24,. 8  •  The  hydroperoxides  were reduced by L i A l H  c o r r e s p o n d i n g a l c o h o l s and i d e n t i f i e d . r e s u l t s of t h i s  4  t o their  T a b l e 12 shows t h e  analysis. T a b l e 12 Hydroperoxides o b t a i n e d at §5°C by Chauvel and h i s c o - w o r k e r s . 86  A = CH -CH-CH=CH2 3  OOH B = CH -CH=CH-CH OOH 3  Butene 1-butene 2-butenes (75% c i s 25% t r a n s ) trans-2-butene cis-2-butene  2  A%  B%  90 55  10 45  9 1.2  45 47  55 53  0.8 0.9  A/B  F i g s . 17—18.  The r e l a t i o n s h i p between the Oxygen absorbed and the Hydroperoxide produced, obtained by Chauvel et al° .  75 T a b l e 13 shows the r e s u l t s of an a n a l y s i s of geometric isomers i n B. T a b l e 13.  s  A n a l y s i s of geometric isomers of the B hydroperoxide by Chauvel and h i s co-workers I n i t i a l Butene  5  trans%  -cis%  6.1  93.9  B  BxlOO/(A+B)  £rans%  cis%  95  .  52.6  34.2  65.8  54.8  9.6  90.4  These r e s u l t s give the s e l e c t i v i t y  of c i s - B  hydro-  peroxide from cis-2-butene t o be 36.5%, and that of t r a n s - B hydroperoxide from trans-2-butene t o be 91.8%. The p r o d u c t i o n of t h e hydroperoxides was e x p l a i n e d i n t h e mechanism: CHgCHg—CH CHg  CH3CH=CH-CH2  —  -H  -H  (80)  GHgCH "CH—CHg  CHgCHCH—CHg  -  (R)  (R) CH CHCH=CH 3  + 0  2  ->  2  CH CHCH=CH 3  (81)  2  00* C H CH=CHCH 3  CH CHCH=CH 3  2  + 0  2  2  (82)  CH CH=CHCH 00 3  + 1- or 2-butene  2  CH CHCH=CH 3  2  + R  (83)  OOH  00'  (A) CH CH=CHCH 00 3  2  + 1- or 2-butene  CH CH=CHCH 00H + R 3  2  (B)  __.(84)  76  The  o v e r a l l mechanism was  assumed t o f o l l o w the w e l l -  known s t e p s i n d i c a t e d as f o l l o w s : Initiation:  Initiator  Propagation:  R R0  Termination:  0  +  2  +  2  RH  R + R R + R0 R0  2  + R0  2  2  —*~.. R  r a t e = R^  — ^  R0  —*-  ROOH  —>—»-  products-* I r a t e consp r o d u c t s ) t a n t kt  —>.  products'  1  2  +-R)  r  S  a  T  t  A  Under the e x p e r i m e n t a l c o n d i t i o n s ; p e r t a i n i n g , recombination process.  of R 0  2  was  e  N  T  c  o  K  P  n  _  the  c o n s i d e r e d t o be the major t e r m i n a t i o n  S t a t i o n a r y s t a t e c o n s i d e r a t i o n s would g i v e r i s e t o  the e x p r e s s i o n d  which was  <  R 0 0 H  dt  = k k -4RJ p t i  >  found toi:be c o r r e c t .  (RH)  In a u t o x i d a t i o n , t h a t i s ,  o x i d a t i o n i n i t i a t e d by the decomposition  of i t s own  hydro-  p e r o x i d e s , the r a t e of i n i t i a t i o n R ^ i s g i v e n by the e q u a t i o n : -  R  ±  where k  d  = k (R0QH)  2  d  i s the r a t e constant f o r the decomposition  of R O O H .  T a b l e 14 shows the v a l u e s of the r a t e c o n s t a n t s o b t a i n e d by these  authors.  77 T a b l e 14. Rate constants o b t a i n e d by Chauvel and h i s co-workers°° •  Rate Constant k  p t  k  d  k  t  k  p  k  *  l^mole s e c *  4.4xl0  T - l "I 1 mole sec 1 mole sec "'"  SxlO 2xl0  1 mole^sec  1.9xl0  z  !  -1  2-Butenes  1-Butene  -  - 1  3 e  1 1 e  -  -  1  2  6  0  0  0  °/  0  0  0  /  R  R  T  1.2X10  5x10  T  lxlO  7  7 e  -  1  0  0  0  0  /  R  E  1 2 e  -  9  2  8  0  0  0  0  0  0  /  /  R  R  T  T  6  1.2xl0  T  -  3  6  e  9  0  0  0  /  R  T  22  With t h e e x c e p t i o n of Dobrinskaya and Neiman 23 t o a c e r t a i n extent, N o r r i s h  and P o r t e r  and,  , none of the above-  mentioned authors s t u d i e d the k i n e t i c s of the r e a c t i o n between molecular oxygen and 2-butenes d u r i n g the i n d u c t i o n p e r i o d . The quantity ( \ , used by B l u n d e l l and S k i r r o w as a measure V Anax d  A  d  t  P  2 1  of r a t e , probably marked the commencement of o v e r a l l r a t e acceleration. oxidation  T h i s was due t o theVdegenerate branching i n the  of acetaldehyde, a product i n the o x i d a t i o n  butenes, and probably not due t o : t h e o x i d a t i o n  of 2-  of 2-butenes  themselves. The the  present study of t h e o x i d a t i o n  of 2-butenes i n  gas phase was made i n order t o t r y t o e l u c i d a t e the k i n e t i c s  of the r e a c t i o n d u r i n g  the i n d u c t i o n  period,  a l s o the commencement of r a t e a c c e l e r a t i o n .  and t o i n v e s t i g a t e The experiments  were c a r r i e d out i n a c o n v e n t i o n a l s t a t i c system f o l l o w e d by a n a l y s i s w i t h gas chromatography, which was not a v a i l a b l e f o r 21 22 21 23 the e a r l i e r two ' of the t h r e e gas phase s t u d i e d , as the t o o l f o r a n a l y s i s .  78 2. Experimental (i)  Details  Apparatus The  apparatus used i n the present study was  a con-  v e n t i o n a l s t a t i c vacuum system s c h e m a t i c a l l y shown i n F i g . 19. The r e a c t i o n v e s s e l was 1875  cc.  made of Vycor  and had a c a p a c i t y of  A thermocouple w e l l had been i n s e r t e d i n t o the v e s s e l  t o allow an accurate measurement of temperature.  A l l leads  were wrapped w i t h h e a t i n g tape and heated t o about 50°C. The r e a c t i o n v e s s e l was furnace.  The  p l a c e d i n a very w e l l i n s u l a t e d  o u t s i d e of the furnace was  t u b i n g through which c o o l i n g water was winding was  wrapped w i t h  passed.  The  copper  heater  i n two p a r t s , one f o r continuous h e a t i n g and  the  other f o r inte:rmi.ttent h e a t i n g c o n t r o l l e d by a Honeywell Model Y156C18-V(S)H-61 (range 7-17 chromel-alumel  mv)  controller.  thermocouples were used,  Two  p a i r s of  one p l a c e d i n the  thermocouple w e l l of the r e a c t i o n v e s s e l f o r a c t u a l  temperature  measurement, and the other along the h e a t i n g w a l l f o r thermostatic control.  Thermocouple r e a d i n g s were made on a Rubicorn  Model 2700 potentiometer. t r o l l e r r e a d 0.08-Q.09 mv  It was  found t h a t the Honeywell con-  h i g h i n the experimental  The Pyrex s p i r a l gauge was blower i n t h i s Department and was  range.  c o n s t r u c t e d by the  glass-  capable of w i t h s t a n d i n g +1  between the i n s i d e and o u t s i d e of the s p i r a l and was  quick  enough i n response t o detect c o o l flame e x p l o s i o n s .  F i g . 20  shows i t s c a l i b r a t i o n w i t h the l i g h t away.  and s c a l e mounted about 1 m  The s p i r a l gauge showed no v i b r a t i o n s and i t s readings  were h i g h l y r e p r o d u c i b l e and accurate t o about 0.5 scale.  atm  mm  U s u a l l y , o n l y the l i n e a r p a r t of the gauge was  on the used  Fig.  19.  Apparatus f o r the study of the Thermal O x i d a t i o n of 2-Butenes by Molecular Oxygen.  :To manometer  Spiral  Scale  Gauge T o vacuum line and storage  Lamp Thermocouples: measure —  To  g  a s chromatography  system  controf  Reaction vessel Heater  Cooling water  winding Furnace  to  F i g . 20. 14  C a l i b r a t i o n of S p i r a l Gauge. Slope = 0.285 mm Hg/mm d e f l e c t i o n .  Spiral  Gauge  Scale  in  cm  81 and the c a l i b r a t i o n gave 0.285 mm  Hg/mm d e f l e c t i o n of s c a l e .  T a b l e 15 shows the volumes of v a r i o u s p a r t s of the apparatus. Table  15.  Volumes of v a r i o u s p a r t s of the  Part  Volume cc  Reaction v e s s e l  Surface  . in  Volume  „ -l cm m  0.4  1875 31.6  E n c l o s e d by stopcocks (1),(2) & (3)  (ii)  apparatus  E n c l o s e d by stopcocks (3) & (4) i n c l . s p i r a l gauge  21.6  Gas sampling b u r e t t e ( i n gasr chromatography system)  32.4  Materials Cis-  and trans-2-butenes  were P h i l l i p s Research Grade  q u a l i t y and were degassed and b u l b - t o - b u l b d i s t i l l e d b e f o r e The  only i m p u r i t y d e t e c t e d was  geometric  iosmer,  as claimed by the  Oxygen was through  about 0.1  mole % of the wrong  manufacturer.  o b t a i n e d from Canadian L i q u i d A i r Co.,  a dry i c e t r a p and b u l b - t o - b u l b d i s t i l l e d  n i t r o g e n temperature b e f o r e use.  No  i m p u r i t y was  at  liquid  found.  Compounds f o r c a l i b r a t i o n purposes were o b t a i n e d through  normal commercial  channels.  use.  dried  82 (iii)  Analysis The gas chromatography system has been d e s c r i b e d on  pages 28-33.  I d e n t i f i c a t i o n Of products was made by t h e  r e s p e c t i v e e l u t i o n times and by i n f r a r e d spectrophotometry.  The  i n f r a r e d spectrum of a product p r e v i o u s l y trapped out at t h e e x i t of t h e gas chromatography system, was compared w i t h that of a commercially a v a i l a b l e sample which has been p u r i f i e d by t h e same chromatography column and trapped i n t h e same way as t h e product. Quantitative measurements  were made by comparing gas  chromatography peak areas between the product i n q u e s t i o n and t h e 2-butene r e a c t a n t , u s i n g the DNP column and t h e flame i o n i z a t i o n detector.  T h i s method of u s i n g t h e r e a c t a n t as an i n t e r n a l  standard was not dependent on any v a r i a t i o n i n t h e absolute s e n s i t i v i t y of t h e d e t e c t o r .  Since the consumption o f 2-butene  was not allowed beyond 1%, t h i s method of q u a n t i t a t i v e  measure-  ment was i n p r i n c i p l e very a c c u r a t e . The method f o r t h e a n a l y s i s f o r peroxides has been d e s c r i b e d on pages 41-42.  In t h i s case, t h e contents of t h e  r e a c t i o n v e s s e l were i n i t i a l l y condensed i n t h e U-trap i n t h e gas sampling b u r e t t e .  (iv)  Procedure -5 The r e a c t i o n v e s s e l was evacuated t o b e t t e r than 10  measured by a MacLeod gauge i n t h e h i g h vacuum l i n e .  mm,  If this  vacuum was not achieved, r e s u l t s would not have been r e p r o d u c i b l e but would have shown s i g n s of i n h i b i t i o n .  I f an experiment was  83 allowed t o proceed beyond the i n d u c t i o n p e r i o d , a minimum of 3 hours pumping was a.  necessary t o reach t h i s degree of vacuum.  Pressure-time s t u d i e s Predetermined p r e s s u r e s of 2-butene and oxygen were  admitted i n t o the r e a c t i o n v e s s e l . c l o s e d , but  (2) and  (3) were l e f t  Stopcocks open.  (1) and  (4) were  Pressure-time readings  were taken u n t i l the p r e s s u r e l e v e l l e d o f f again a f t e r the commencement of the sudden p r e s s u r e i n c r e a s e .  A sample was  expanded t o the gas sampling b u r e t t e f o r gas  then  chromatographic  analysis. b.  K i n e t i c s t u d i e s d u r i n g the i n d u c t i o n p e r i o d Reactants were admitted i n the p r e v i o u s f a s h i o n .  Stopcock  (2) was  sample was (2) and  then c l o s e d .  allowed t o f i l l  (3).  sample was  the volume e n c l o s e d by stopcocks (1),  T h i s sample was  taken.  T h i s was  At a predetermined time, a  d i s c a r d e d , but, immediately  another  then allowed t o expand i n t o the; gas  sampling b u r e t t e i n the chromatography system.  An a n a l y s i s  was  then made. Since the volume e n c l o s e d by stopcocks (1), (2) and was  very s m a l l compared t o that of the r e a c t i o n v e s s e l ,  such samplings  (3)  two  i n the ;same run c o u l d be made without a p p r e c i a b l y  lowering the p r e s s u r e i n the r e a c t i o n v e s s e l .  A third  sample  c o u l d be taken at the end of the run. When products were t o be s e p a r a t e d and trapped f o r i n f r a r e d spectrophotometry, the whole mixture was  condensed  i n the U-trap i n the sampling b u r e t t e w h i l e pumping through the other end of the b u r e t t e .  84 3. Experimental R e s u l t s (i)  Pressure-time s t u d i e s a.  pQ > Pp_h^t-ftnf>> commencement of c o o l flame 2 A t y p i c a l pressure-time curve f o r an experiment  the r a t i o of pg /P2-butene 2  w  a  g r e a t e r than u n i t y but not very  s  l a r g e and i n which t h e i n i t i a l i s shown i n F i g . 21. at  i n which  t o t a l p r e s s u r e was about 51 mm Hg  I t i s obvious t h a t two c o o l flames o c c u r r e d  the end of the i n d u c t i o n p e r i o d . F i g . 22 shows a t y p i c a l pressure-time curve f o r an i n which the r a t i o of pg /P2-butene large. 2  experiment  w  a  s  v  e  r  v  There was a p o s i t i v e p r e s s u r e change at t h e end of the i n d u c t i o n p e r i o d , but no c o o l flame.  A c l e a r - c u t t r a n s i t i o n p o i n t was not  found between the two modes of p r e s s u r e change at t h e end of the induction period. A very s m a l l p r e s s u r e drop, error  i n t h e order of e x p e r i m e n t a l  (0.15 mm Hg) was observed towards the end of t h e t h e induc-  tion period. b  Pa-hntenp > P Q  -  2  When P 2 - b u t e n e ^ 0  '  p  n  o  m  e  a  s  u  r  a  b  l  e  (0.2 mm Hg) p r e s s u r e  2 change was observed.  A p l o t of ^P/P2-butene>  p r e s s u r e change t o t h e i n i t i a l  *  n  e  r  a  t  i  o  °* t o t a l  2-butene p r e s s u r e , a g a i n s t  ^2-butene * i n i t i a l t o t a l p r e s s u r e s of 51 and 41 mm Hg i s a  shown i n F i g . 23. P2-butene 0 / p  c.  - s 2  It appears  that  A p  /P2-butene~  > :  * 1  T o t a l p r e s s u r e change  AP  A l i n e a r r e l a t i o n s h i p was found between and P2-butene  a  ^ when  t  ^P/P2-butene  an i n i t i a l t o t a l p r e s s u r e of 51 mm Hg, w i t h a  F i g . 21. 64  P r e s s u r e - t i m e study, c o o l flame Run 17 P =51.0 mm  region  i  (Po )i = 37.8 mm 2  ^Bu)  62  T  i  = 13.1 mm = 289°C  60h  ^  e  58  R  £ 56U  54  52  k  501  io  TO Reaction  30  time  in min  40  So  F i g . 22.  P r e s s u r e - t i m e study, slow combustion r e g i o n . Run 18 P -  = 50.3 mm  ±  6o  (P 0 ) 2  ±  = 42.3 mm  ( B u )± = 8.0 mm T = 289°C P  58  561  E  54 I  2? tn  in <o  i.  CL  52  50  48  I  no  )20  130  Reaction  time  in  min  wo  oo  87  F i g . 23.  R e l a t i o n s h i p between t o t a l pressure i n c r e a s e and i n i t i a l 2-butene p r e s s u r e .  88 s l o p e of -0.060 mm"-^  and an i n t e r c e p t of 1.66, as shown i n F i g . 23  From the two values of P/P2-butene A  of  a  t  a  n  i  n  i  t  i  a  total  l  41 mm Hg, i t i s p o s s i b l e t o reach an approximation  pressure relation-  s h i p which i s : * P - b u t e n e - 1.66 - ^ i -  ^-butene  or  AP = 1.66 P -butene - — P  ^-butene)  where  A P = t o t a l i n c r e a s e i n p r e s s u r e , measured a f t e r the t o t a l pressured- had l e v e l l e d o f f a f t e r the sudden p r e s s u r e change at the end of the i n d u c t i o n p e r i o d , i n mm Hg:  P /  2  2  P  = i n i t i a l t o t a l p r e s s u r e i n mm Hg:  ^2-butene  d.  2  i n i t i a l p a r t i a l p r e s s u r e of 2-butene, i n mm Hg.  =  The i n d u c t i o n p e r i o d Fig.  T  24 shows the r e l a t i o n s h i p between t h e i n d u c t i o n  p e r i o d and P2-butene  a  t  t  w  o  i  n  i  t  i  a  l  t o t a l pressures.  It i s clear  that the i n d u c t i o n p e r i o d decreased with an i n c r e a s e i n the p r e s s u r e of 2-butene. The r e l a t i o n s h i p between the i n d u c t i o n p e r i o d , T 1  /(P2_butene^  2  i  s  a  PProximately  , and  l i n e a r as shown i n F i g . 25 and  can be represented, f o r P = 51 mm Hg, i n the f o l l o w i n g way :_  X =  7.55xl0  ( 2-butene) p  Q + 8  3  min  2  where T i s i n minutes and P2-butene 2-butene i n mm Hg.  I t i s important  i  s  i n i t i a l p r e s s u r e of  t o note that the i n t e r c e p t  i s not zero but has a p o s i t i v e v a l u e . A summary of r e s u l t s of pressure-time  studies i s  F i g . 24.  R e l a t i o n s h i p between i n d u c t i o n  .  _ i  •  30  2o  IO P  +rnns-2 -butene  mm He  period  oo  CO  91 i n c l u d e d i n Appendix V I I . ( i i ) Products of the r e a c t i o n a.  Products d u r i n g  and a f t e r the i n d u c t i o n  period  F i g . 26 shows gas chromatography a n a l y s i s r e s u l t s f o r products d u r i n g  and a f t e r the i n d u c t i o n p e r i o d f o r a t y p i c a l  k i n e t i c run, u s i n g the DNP column and the flame i o n i z a t i o n detector.  I t i s obvious that d u r i n g the i n d u c t i o n  acetaldehyde was the main product. t i o n p e r i o d , other  products,  period,  A f t e r t h e end of the induc-  such as methanol and formaldehyde,  appeared i n l a r g e q u a n t i t i e s , i n general r e s u l t s of B l u n d e l l and Skirrow  21  agreement w i t h the  and of N o r r i s h and P o r t e r  During the i n d u c t i o n p e r i o d , products separated the DNP column were t e s t e d f o r peroxide. result.  T o t a l peroxide c o n c e n t r a t i o n  23  on  None gave a p o s i t i v e  was d e t e c t a b l e  only  around t h e end of the i n d u c t i o n p e r i o d and was at a maximum at the commencement  of the sudden pressure  t o about \ of the c o n c e n t r a t i o n  r i s e , but amounted  of the acetaldehyde at that  point. F i g . 27 shows s i m i l a r analyses  as F i g . 26, u s i n g the  HMPA column and the flame i o n i s a t i o n d e t e c t o r .  It i s seen t h a t  only t r a c e amounts of hydrocarbons were produced during the i n d u c t i o n p e r i o d , but these appeared i n large q u a n t i t i e s a f t e r wards.  T y p i c a l q u a n t i t a t i v e values  are shown i n Table 20,  page 110.8. F i g . 28 shows the same a n a l y s i s as i n F i g . 27, but the t h e r m i s t o r  d e t e c t o r was used.  d i o x i d e i s c l e a r l y shown.  The appearance of carbon  During the i n d u c t i o n p e r i o d ,  carbon  92 F i g . 26.  Product a n a l y s i s on the DNP 58°C 5 p . s . i . g . Helium c a r r i e r . Flame I o n i z a t i o n D e t e c t o r . Run 30.  Column <u § «>  a  -p co £~ i Q) -CM  •a  Elution t i m e  i o min  93 F i g . 27.  Product a n a l y s i s on the HMPA Column  c  CQ i I  W  Helium 0"C  carrier  8 p.s.i.g.  Flame I o n i s a t i o n Detector  Run  47  Reaction (a)  time  8-0 min  (<T)  ( b ) 49.0min  (>r)  94 F i g . 28. A n a l y s i s of COg on the HMPA Column,Helium c a r r i e r 0°C 8 p.s.i.g.-Thermal conductivity ddtector.  0) E 0) 4 3  CO CM  I  Run 47.  w  Reaction time: (a)  2 2 . 0 min  ( b)  49 0  min  (<T)  {>T)  Elution  time  10  min  95 d i o x i d e was produced only i n t r a c e q u a n t i t i e s , but was suddenly produced i n l a r g e amounts t h e r e a f t e r . Table 16 shows the analyses the Molecular detector. detected  Sieves  of a t y p i c a l run u s i n g  column and the thermal c o n d u c t i v i t y  Carbon monoxide, carbon d i o x i d e  and methane were not  d u r i n g the i n d u c t i o n p e r i o d but appeared i n l a r g e  q u a n t i t i e s immediately t h e r e a f t e r .  Carbon monoxide and methane  were, however, subsequently consumed.  The maximum i n methane  concentration  i n carbon monoxide  concentration.  appeared l a t e r than that  Carbon d i o x i d e c o n c e n t r a t i o n ,  appeared t o remain  however,  constant.  During the i n d u c t i o n p e r i o d , no crotonaldehyde was 21 i n agreement with B l u n d e l l and Skirrow and w i t h 23 N o r r i s h and P o r t e r but i n c o n t r a s t t o the r e s u l t s of 22 Dobrinskaya and Neiman T a b l e 16 + A n a l y s i s by Molecular Sieves 5A Column at room temperature. Pressure: 8 p . s . i . g . C a r r i e r gas: helium. Flowrate: 220 cc/min. detected,  Run 68. PQ  2  = 24.5 mm Hg, Pg-butene = 25.5 mm  T = 294.5°C t min  0%  CO  P  Induction  m  m  H  g CH4  period  ~ 1 8 min.  CC-2  12 .0  24. 5  15,.0  22.2  -  21 .0  0 .76  0,,67  0 .09  15.75  29 .3  0.39  0 ,33  0 .58  15.95  53 .0  0.44  0 . 10  0 .06  15.39  Hg  •—  -  The molecular s i e v e s had been damaged by t h i s time so that Ng and Og no longer c o u l d be separated and COg was not i r r e v e r s i b l y absorbed.  96 b.  I d e n t i f i c a t i o n of products Hydrocarbons  and COg were i d e n t i f i e d by t h e i r  times on t h e HMPA column.  elution  Inorganic gases were further i d e n t i f i e d  by the f a c t that when both t h e flame i o n i s a t i o n and t h e thermis-* t o r d e t e c t o r s were used, the i n o r g a n i c gas was d e t e c t e d only by the  latter. Pure and l a r g e samples  of acetaldehyde were r e a d i l y  c o l l e c t a b l e from t h e e x i t of the gas chromatography the  DNP column.  system u s i n g  A good i n f r a r e d spectrum of t h e acetaldehyde  product was made and found t o be i d e n t i c a l w i t h one from a commercial product s i m i l a r l y p u r i f i e d on the DNP column. dehyde was f u r t h e r  Acetal-  i d e n t i f i e d by i t s e l u t i o n time on both the  DNP and HMPA columns. P r o p a n a l was i d e n t i f i e d by i t s e l u t i o n time and by i t s i n f r a r e d spectrum.  The e l u t i o n times f o r a c r o l e i n and acetone  were very c l o s e t o .that of p r o p a n a l , but the acetone  infrared  spectrum was v a s t l y d i f f e r e n t from the comparative sample. i n f r a r e d spectrum of a c r o l e i n was s i m i l a r t o with one important e x c e p t i o n .  T h i s peak was t o t a l l y  from t h e i n f r a r e d spectrum o f the product. that very l i t t l e ion period.  acrolein,  that of t h e product,  The highest a b s o r p t i o n peak f o r  a c r o l e i n i s at about 3500 c m . -1  The  absent  I t can be concluded  i f any, was formed d u r i n g the i n d u c t -  T h i s i s i n disagreement w i t h the r e s u l t s of N o r r i s h  23 and P o r t e r  who i d e n t i f i e d a c r o l e i n from t h e r e l a t i v e  retention  volume alone. Isobutanal and butanone-2 were i d e n t i f i e d by t h e i r e l u t i o n times and t h e i r i n f r a r e d s p e c t r a .  Since only s m a l l  samples were c o l l e c t e d , the s p e c t r a were not very c l e a r , but  97 showing u n d i s p u t e d l y C-H  and C=0  p o s i t i v e i d e n t i f i c a t i o n was knowledge of e l u t i o n  stretchings.  Nevertheless,  p o s s i b l e i n c o n j u n c t i o n with the  times.  n-Butanal was  i d e n t i f i e d by e l u t i o n time  alone.  ( i i i ) Kinetic studies a.  During the i n d u c t i o n p e r i o d F i g . 29 shows l o g p ( o b t a i n e d from peak area) against  time curves f o r the f o u r main products i n the same run.  It .  should be noted t h a t the p a r t i a l p r e s s u r e s were c a l c u l a t e d gas chromatography peak areas without tivity  regard to r e l a t i v e  from  sensi-  and t h a t the peaks f o r acetaldehyde, propanal and i s o b u -  t a n a l were sharp w h i l e those f o r n-butanal and butanone-2 were only bumps and c o u l d e a s i l y be  overestimated.  F i g . 30 shows t h r e e t r e n d s of l o g p a g a i n s t t r e l a t i o n s h i p under t h r e e d i f f e r e n t acetaldehyde.  types of experimental c o n d i t i o n s f o r  These t r e n d s were c o r r e s p o n d i n g l y f o l l o w e d by  other products as w e l l . .  There appears t o be a l i n e a r  relation-  s h i p between l o g p and t at very low c o n v e r s i o n s and t h i s can MI- "  r e p r e s e n t e d as  ' •  log p = 0 t . Actually, PCH3CHO  *  a n c i  P2-butene b.  at very low c o n v e r s i o n s , the r e l a t i o n s h i p between  w  e  r  i s  e  l i  n  e  a  r  a  s  shown i n F i g . 31 where both pQg  very s m a l l (the order of 5 mm  E f f e c t of the r a t i o t o t a l pressure  (P g /P2-butene) * a  f°  r  each). constant  2  F i g . 32 shows p l o t s of l o g R log(PQ2-butene)  Hg  i  and  acetaldehyde, where  log 0 against  a  n  d  be  98 F i g . 29.  P r o d u c t i o n of acetaldehyde, propanal, i s o b u t a n a l , n-butanal and butanone-2  Run 4/  x  40  60  80  100  Reaction time in min  120  140  160  101  F i g . 32.  R e l a t i o n s h i p between l o g R^, l Q  g  (POQ/PBU)  f  o  r  l o g 0 and  acetaldehyde  102  3  R^ = ( A p g j j ^ j j Q / A t ) ^ ^ Q =  m  propanal and i s o b u t a n a l . log  i n  F i g . 33  shows s i m i l a r p l o t s f o r  It should be noted t h a t while the  curves are s i m i l a r i n a l l t h r e e cases, the maxima i n the  l o g 0 curves do not occur at the same POg/P^ butene ''- ' va  ^  ue  o r  t h i s maximum occurs at about l o g (Po P2-butene^  acetaldehyde,  //  =  0  °'  but f o r ; p r o p a n a l and i s o b u t a n a l , the maxima occur at the value of about  0.2.  c.  Reaction order F i g . 34  (P2-butene)  shows p l o t s of l o g 0 and l o g R i against l o g  constant PQ  a t  2  s l o p e of the l o g R  26.8  mm  Hg f o r acetaldehyde.  The  l i n e g i v e s the order of r e a c t i o n with r e s -  i  pect t o 2-butene.  =  The  order of r e a c t i o n with r e s p e c t t o 2-  butene f o r propanal and i s o b u t a n a l were o b t a i n e d from s l o p e s of similar plots.  It should be noted t h a t the v a l u e s of  sented a maximum of 1.5% measures of i n i t i a l The  consumption of 2-butene and were t r u e  rate.  orders of r e a c t i o n with respect t o oxygen were  o b t a i n e d from s l o p e s of p l o t s of l o g R• * ( 2-butene^ ) with t o t a l p r e s s u r e s of 51-52  acetaldehyde  repre-  and l o g  R ^ <P2-butene)  for  f o r propanal against l o g  p  (PQ  2  i n F i g . 35.  mm  Hg.  These p l o t s are shown  The values f o r i s o b u t a n a l s c a t t e r e d too much t o  allow a l i n e t o be drawn. The  r e a c t i o n orders f o r acetaldehyde,  i s o b u t a n a l p r o d u c t i o n are summarized i n Table  propanal 17.  and  -0-4  O  - 0 3. l o  9  ^  0.2  /Pi-Butene )  0.4  06  0-6  104  —i  08  1 lo  1 1.4-  1  12  '°9  ^trans-2-Bufene  1  1 1.6  i_  1.8  F i g . 35.  105 Determination of r e a c t i b h o o r d e E wj:th:iiiespect t o oxygen f o r acetaldehyde and p-ropanal production.  106 Table 17 R e a c t i o n orders f o r acetaldehyde, propanal and isobutanal productions.  Product  Order w i t h respect t o 2-butene 3.01+0.17  Acetaldehyde  Order with respect t o 2-butene  0.  1.95+0.32  1.02  Propanal  3.58  2.16  2.1  Isobutanal  2.16  -  2.06  The v a l u e s f o r the c a l c u l a t i o n of 0 r e a c t i o n order with r e s p e c t t o 0g were t o o s c a t t e r e d t o allow a reasonable l i n e t o be drawn. It i s obvious from Table 17 t h a t 0 i s not a measure o f t h e reaction rate. Rate e x p r e s s i o n s f o r the f o r m a t i o n of products can now be w r i t t e n d(Acetaldehyde)  ^^.g^ene)3 ^ 2  =  d(Propanal) — dt d( isobut anal) dt  , , _ . \3.5 v2 = k (2^Butene) (0 ) " , utene) (0 ) . * / r t  n  2  2  =  k  ( 2  ?  2  B  1  A summary of the r e s u l t s of k i n e t i c s t u d i e s i s i n c l u d e d i n Appendix VITI. d.  O v e r a l l a c t i v a t i o n energy ( E ) and frequency f a c t o r (A) f o r k &  a  The value of k , the o v e r a l l r a t e constant f o r t h e a  p r o d u c t i o n of acetaldehyde, was determined  over s i x temperatures  107 i n the range of 289-357°C f o r both c i s - and trans-2-butenes. F i g . 36 shows p l o t s of l o g k  a  against l / T .  The values of E  &  and A, c a l c u l a t e d by the l e a s t - s q u a r e method, are shown i n Table 18. Table 18 E„ and A values f o r c i s - and trans-2-Butene. a — E  a  ——  2-Butene  Quantity kcal/mole  cis trans Overall ; .52.6*3.35 .5217*1.5' .53.4±2.4  log A ( l m o l e ~ s e c ) 4  4  _ 1  27.2±0.1  27.4±0.6  27.6+0.9  It s h o u l d be noted t h a t the d i f f e r e n c e s i n E  a  and A  between c i s - and t r a n s - forms of 2-butene are much l e s s than the experimental e r r o r .  This observation i s i n general  agree-  21 ment w i t h the r e s u l t s of B l u n d e l l and Skirrow  and of N o r r i s h  23 and P o r t e r  . A summary of the various. k  ponding temperatures e.  &  v a l u e s and t h e i r c o r r e s -  i s shown i n Appendix IX.  Thermal I s o m e r i z a t i o n of cis-2-butene t o isobutene 24.8 mm Hg cis-2-butene was heated  r e a c t i o n v e s s e l at 291°C.  Samples were withdrawn at i n t e r v a l s  and analyzed on the HMPA column. was observed.  alone i n the  I s o m e r i z a t i o n t o isobutene  R e s u l t s are shown i n Table 19.  109 Table  19  Thermal I s o m e r i z a t i o n of cis-2-butene t o isobutene at 291°C.  Hydrocarbon  8.5  % Product at t min 21.6 50.0  Isobutene  0.00822  0.0143  0 .0253  trans-2-butene  0.131  0.0910  0.0777  Isobutene + trans-2-butene  0 . 139  0 . 105  0.103  It should be noted that the o r i g i n a l c i s - 2 - b u t e n e r c o n t a i n e d no isobutene but about 0.1% only i m p u r i t y .  of trans-2-butene  as the  T a b l e 19 shows t h a t isobutene i n c r e a s e d with  time but trans-2-butene  decreased w i t h time.  isobutene and trans-2-butene,  The  however, decreased  ning but seemed t o l e v e l o f f l a t e r .  sum  of  at the b e g i n -  T a b l e 19, however, shows  no evidence of thermal c i s - t r a n s i s o m e r i z a t i o n .  f.  Cis-trans isomerization 25.0  mm  Hg of cis-2-butene and 26.8  mm  were admitted t o the r e a c t i o n v e s s e l at 289.5°C.  Hg of oxygen Analyses  the HMPA column showed both i s o m e r i z a t i o n t o isobutene catalyzed cis-trans isomerization. Table 20 .  and  R e s u l t s are shown i n  on  110 T a b l e 20 Cis-2-butene i s o m e r i z a t i o n t o trans-2-butene and isobutene at 289.5°C. % at t min  Hydrocarbon  22.00  8.P  49 .0(>T )  Isobutene  0 .0091  0 .026  0 .356  trans-2-Butene  0 . 101  0 .286  4 .54  cis-2-Butene  99 .8  99 .4  31 . 1  Acetaldehyde  0 .064  0 .327  0 . 184  Methane,  -  •-  1 . 19  Propane  0 .0003  0 .0004  4 .06  Propylene  0 .0007  0 .0003  0 .010  Isobutane  0 .0015  0 .0048  1 .06  Acetylene  0 .0009  0 .0009  0 .036  ethane  4.  Discussion  (i)  General The  appearance of c o o l flames, shown i n F i g . 21,  not observed by B l u n d e l l and Skirrow at the same temperature  whose pressure-time  i s shown i n F i g . 16a.  From the  was curves  observa-  t i o n s made i n the present study, the experimental c o n d i t i o n s i n which F i g . 16a was  obtained, namely, (P02 2-butene) //p  give pressure peaks as shown i n F i g . 21. s m a l l decrease  On the other hand, the  i n t o t a l pressure s h o r t l y p r e c e d i n g the sudden  r i s e i n t o t a l pressure observed by these authors absent  i n the present The  S-shape ias Porter p  was  0 2  2 3  ^' should  =  (Fig.16 a)  was  study.  pressure-time curve shown i n F i g . 22 i s of a simple  observed by B l u n d e l l and Skirrow* at a much higher temperature  much l a r g e r than  P _ 2  b u t e n e  and by N o r r i s h and  ( F i g . 16b).  In both cases,  -  There i s c o n s i d e r a b l e d i f f e r e n c e i n the v a l u e s of  AP,  the o v e r a l l i n c r e a s e i n t o t a l p r e s s u r e , between the present  study  21 and the work of B l u n d e l l and Skirrow the p l o t of (^P/P2-butene>  A P is calculated  against P2-butene ( g Fi  experimental c o n d i t i o n s and compared with the  >  A P found  B l u n d e l l and S k i r r o w ^ under the same experimental 1  These are shown i n Table  23  f  o  r  from t  w  o  by  conditions.  21. Table  21  Comparison of A P v a l u e s between the present work and the study by B l u n d e l l and S k i r r o w . T = 289°C. 2 1  P<3  m  2  m  P2-butene  Present work ( AP/p _butene) 2  30  22  0.345  37  15  0.76  Blundell & ^ P mm  7 .6  mm 4,.0  11,.4  8 .5  Skirrow  112 It i s seen that the A P values obtained by B l u n d e l l 21 and Skirrow  are lower than the present study.  No a p p r e c i a b l e  (0.15 mm Hg) pressure drop b e f o r e the end of t h e i n d u c t i o n p e r i o d has been observed, B l u n d e l l and S k i r r o w  2 1  i n c o n t r a s t w i t h the r e s u l t s of  and of N o r r i s h and P o r t e r  2 3  .  The d i f f e r -  ences i n ^ . P and pressure drop values can be e x p l a i n e d by the higher s u r f a c e t o volume r a t i o and much s m a l l e r (ten times) 21  volume used by these authBdrs. a c t u a l l y found  B l u n d e l l and Skirrow  have  an i n h i b i t i o n e f f e c t on i n c r e a s i n g the s u r f a c e t o O Q  volume r a t i o and N o r r i s h and P o r t e r  have observed  an i n c r e a s e  i n maximum r e a c t i o n r a t e with an i n c r e a s e i n r e a c t i o n . v e s s e l 21 diameter.  The s u r f a c e t o volume r a t i o i n B l u n d e l l and Skirrow's  system i n t h e i r unpacked c e l l was 1.75 c m the present  - 1  but was 0.4 c m  - 1  in  study.  The i n h i b i t i o n e f f e c t of 2-butene on A P observed by 21 23 B l u n d e l l and Skirrow and by N o r r i s h and P o r t e r has been confirmed sure,  i n t h e present work.  At constant  i n i t i a l t o t a l pres^.i •  A P -*. 0 as P2_butene becomes l a r g e r than P02-  Blundell  and Skirrow expressed t h e i r r e s u l t s i n p l o t s of A P against t h e p a r t i a l pressure of one r e a c t a n t at constant p r e s s u r e s of the other:/reactant.  Nevertheless,  i t i s p o s s i b l e t o determine  t h e i r v a l u e s of pQg and P2-butene summarised i n Table 22.  w  h  e  n  A  p  -*" '0 •  These are  I t appears that agreement i s good  between t h e r e s u l t s of the present work and t h e those of B l u n d e l l 21 and Skirrow i n t h i s aspect. 91 28 B l u n d e l l and Skirrow and others have c o n s i d e r e d that the i n d u c t i o n p e r i o d f o r the r e a c t i o n ends when a c e r t a i n minimum c o n c e n t r a t i o n of acetaldehyde has accumulated. It i s  113 p o s s i b l e t o determine the i n d u c t i o n p e r i o d T 2-butene p r e s s u r e , P2-butene>  from the  initial  t o t a l p r e s s u r e s of 51 mm  a t  Hg  from the f o l l o w i n g e x p r e s s i o n o b t a i n e d from F i g . 25 and page 90: ~  The  =  ;  7.55x10 (P  2-butene  _ . 8 min.  3  )  n  +  r a t e of p r o d u c t i o n of acetaldehyde  P  C  H  3  C  H  °  =  dt  k  a  has been determined  ( -butene) ... P 2  Table  3  (P  0 o  )  t o be  (PU06)  2  z  22  Comparison of C o n d i t i o n s when P 0 PO2 i n i t i a l oxygen p r e s s u r e i n mm Hg P g = i n i t i a l 2-butene p r e s s u r e i n mm Hg =  u  ______ PO  2  PBu  ______  P0 ^ PjBu 2  24  28  0.86  10 18 20 26 48 36 30 15  15 30 36 48 57 57 57 28  0 .67 0.60 0 .56 0 .54 0.84 0.63 0.53 0.54  P0  PBu  2  P0  / p 2  Bu present work  -  -  10 16 23 .7 31.9 57 . 5  16.3 23.7 35.1 63 70 97  0 .43 0 .42 0 .44 0 .38 0 .46 0.59  Blundell & Skirrow  2 1  and at 289°C, log  k  = £1  , . . . where k i s i n mm a  -9.8  (page 107 )  -4.-1 mm  During the i n d u c t i o n p e r i o d , i t has been found t h a t at most 1.5%  of the i n i t i a l  2-butene i s consumed.  and P Q ^ are e s s e n t i a l l y c o n s t a n t s .  On  Thus P2-butene  integration,  114 3 Pacet aldehyde  =  k  (Po ^  ( 2-butene^ p  a  Table 23 shows P e t a l d e h y d e  a  aC  2 T  -  2  * several T values c a l c u l a t e d  from  the above e x p r e s s i o n . Table 23 Calculated p ™ T log k  a  =  =  at s e v e r a l T v a l u e s T o t a l p r e s s u r e P = 51 mm Hg  289°C -4  -9.8 ( k  T min  i n mm  a  v  l/(p )  2  B u  20 50 80 120  mm  0.162xl0" 0.560 " 0.960 " 1.485  cm  -2  PBii  =  PAc  =  pressure of  PBu mm  P  A p l o t of P c e t a l d e h y d e i  s  n  o  t  the i n d u c t i o n p e r i o d at one temperature  acetaldehyde  log p  mm  A c  -1.45 -1.54 -1.63 -1.69  against T  a  It i s obvious that Pacetaldehyde  0 2  27 .1 38.6 41.8 43.8  24 .9 13 .4 10 .2 8 .2  2  2-butene p r e s s u r e  initial  PAc  m  m  0 .0354 0 .0288 0.0234 0.0204  i s shown i n F i g . 37.  constant at the end of and t o t a l p r e s s u r e .  23 N o r r i s h and P o r t e r  have a c t u a l l y found that  1.7 times the  c o n c e n t r a t i o n of acetaldehyde found at the end of the i n d u c t i o n p e r i o d would be necessary t o e l i m i n a t e the i n d u c t i o n p e r i o d completely. The  Semenov t h e o r y ^ (page 4 ) assumes that branching 1  occurs from the very b e g i n n i n g of the r e a c t i o n . t i o n of the degenerate branching agent e x p o n e n t i a l curve w i t h time.  The c o n c e n t r a -  i s p r e d i c t e d t o f o l l o w an  In the case of the 2-butene  o x i d a t i o n by molecular oxygen, (X)  =  (Acetaldehyde)  =  — e k 0 n  (  0  t  ~ . . . (3) (page. 5 ) X)  115  Fig. 37. r  20  C a l c u l a t e d Acetaldehyde  h  I  O  i 2o  i AO  Induction  1  i 60  1 IOO  80  Period  T  in  min  1—  120  116 Moreover, i f  _L__  i s a measure of the o v e r a l l  rate  dt of r e a c t i o n ,  _P  should  a l s o f o l l o w an e x p o n e n t i a l  =  eft ——Tj 02  curve (S-shape)  w i t h time: B  AP The  e  (6)  VZ  f a c t that equation (3) has  not  (page 5)  been found t o be c l o s e l y  obeyed and that the S-shape pressure-time curve has been found t o a r i s e o n l y a f t e r the  induction period  ( F i g . 22,  page  86)  i n d i c a t e s that c h a i n branching probably takes p l a c e only end  of the  induction period.  T h i s phenomenon has oo  1n  been observed i n s e v e r a l other -cases From the r e s u l t s obtained  at  the  previously  OQ  - »- . i n the present  study  and  from the d i s c u s s i o n so f a r , i t i s seen t h a t the maximum r a t e of 21 pressure  i n c r e a s e , used by B l u n d e l l and  Skirrow  and by  Norrish  23 and P o r t e r  as a measure of the r a t e of o x i d a t i o n , cannot be  genuine measure of the r a t e of r e a c t i o n between 2-butene oxygen.  T h i s i s f u r t h e r evidenced by the value  energy obtained. the value  Though B l u n d e l l and  Skirrow have not  The  value  of 51 mm  at 289°C and of the  work i s 52.7 The  period T  given  of a c t i v a t i o n energy i n t h e i r r e p o r t , i t i s p o s s i b l e ;  i n c r e a s e values  present  and  of a c t i v a t i o n  t o estimate t h i s q u a n t i t y from the maximum r a t e of  mole.  a  T h i s value  i s about 75 k c a l /  a c t i v a t i o n energy obtained  + 115  n a s  from the  kcal/mole.  r e l a t i o n s h i p between the  and P2-butene Hg:  385°C.  pressure  length of the  been found t o be,  induction  at a t o t a l  pressure  117 x 10 3 = 15— + 8 2" <P2-butene) 7.55  T  min  (page 88) .  T h i s e x p r e s s i o n bears some s i m i l a r i t y with that o b t a i n e d by 22 Dobrinskaya ture  and Neiman  who  have found t h a t , at a constant mix-  ratio: (p_P )2.1 -20000/T o  where P  Q  e  =  c  o  n  s  t  a  n  t,  i s the minimum t o t a l p r e s s u r e at which a c o o l flame i s  observed. The  r e l a t i o n s h i p of the i n d u c t i o n p e r i o d T  with  r e a c t a n t p r e s s u r e found i n the present study i s a l s o i n q u a l i t a t i v e agreement w i t h the r e s u l t s found by Mulcahy and R i d g e ^ i n 8  a study of the i n d u c t i o n p e r i o d of the o x i d a t i o n of propylene. These authors o b t a i n e d the f o l l o w i n g e x p r e s s i o n : £ - * + /B - g ( C H ) ( Q ) 2  3  6  2  ( C +  3 6 H  ( 0 ) [( 0 2 )+ 2  r (C H )  T  3  where (M^)  +(0 H  2  a n t  3  * ^M-  a  r  *  e  n e  r  e  i P  c  r  o  c  i n t e r d i f f u s i o n of an a c t i v e p a r t i c l e  and are r e l a t i v e t o J Q ^ Fig.  30  (C3Hg) + H6  a  gas and g, a l  s  w  and r are  °f the c o e f f i c i e n t s  and the a p p r o p r i a t e gas,  =1.  (page 99)  between l o g Pacetaldehyde  j  2  6  i s the c o n c e n t r a t i o n of i n e r t  c o n s t a n t s , Jrj H6 of  ) 2  a  shows t h r e e types of r e l a t i o n s h i p n  d  appears that the  r t  relation-  ship l o  S  Pacetaldehyde  =  0  t  found by Dobrinskaya and N e i m a n  +  22  C  ' and by N o r r i s h and P o r t e r 3 2  118 d u r i n g the  i n d u c t i o n p e r i o d , holds only a f t e r the r e a c t i o n  proceeded somewhat f o r ( p / p i. ) > 1 or at i n i t i a l ^2 2-butene n  0  has  stages  r  when t h i s r a t i o i s l e s s than u n i t y . apparently  Both above groups of authors  c a r r i e d out t h e i r i n d u c t i o n p e r i o d s t u d i e s i n the  former c a t e g o r y .  Thus 0 cannot be  a measure of r a t e  constant.  119  ( i i ) Mechanism of t h e thermal o x i d a t i o n o f 2-butenes by molecular  oxygen  ThAtf- mechanism of t h e o x i d a t i o n of 2-butenes  proposed  22  by Dobrinskaya CH CH=CHCH 3  and Neiman  f o r t h e p r o d u c t i o n of acetaldehyde  + 0 —*-CH CH-j-CHCH  3  2  3  *~2CH CHO  3  3  (73)  0 - 0  i s i n c o m p a t i b l e with a l l a v a i l a b l e data which i n d i c a t e t h a t t h e r e ;are c l o s e s i m i l a r i t i e s between p a r a f f i n and o l e f i n o x i d a t i o n s and t h a t i n both cases, t h e i n i t i a l step i n v o l v e s t h e a b s t r a c t i o n o f a hydrogen and does not involve the d i r e c t  addition  of oxygen t o t h e double bond. 21  The mechanism proposed  by B l u n d e l l and Skirrow  v o l v e s t h e f o r m a t i o n o f hydroperoxides subsequent  in-  as i n t e r m e d i a t e s and t h e i r  decomposition:  CH CH-CH=CH 3  (A) + 2-Butene — ^ C H C H - C H = C H  2  3  CO"  + R"  OOH  CH CH|CH=CH 3  2  ^CH CH0  2  3  + CH =CH 2  (83)  + OH  0-j-OH  (77)  CH fcHCH=CH —>CH 3  2  3  + CH =CHCH0 2  + OH  A+OH  (78)  1 Reaction  (77) p r e d i c t s t h e r a t e o f f o r m a t i o n of t h e  CH =CH" r a d i c a l t o be i d e n t i c a l w i t h t h e r a t e of p r o d u c t i o n o f 2  acetaldehyde.  The r e a c t i o n between the C H = C H * 2  molecular oxygen i s k n o w n ' 1 2  1 3  r a d i c a l and  t o produce formaldehyde.  During  the i n d u c t i o n p e r i o d i n t h e o x i d a t i o n o f 2-butenes by molecular oxygen, no formaldehyde has been d e t e c t e d . i s u n l i k e l y t o be important  Thus r e a c t i o n (77)  during the induction period.  120 R e a c t i o n (78) p r e d i c t s the f o r m a t i o n of a c r o l e i n .  During the  i n d u c t i o n p e r i o d , however, no a c r o l e i n has been d e t e c t e d . Therefore, reaction  (78) i s probably unimportant  also.  Norrish  23 and P o r t e r  r e p o r t e d a c r o l e i n , but t h e i r i d e n t i f i c a t i o n depended  on the r e l a t i v e r e t e n t i o n volume alone. A more probable path f o r the decomposition of the b u t e n y l hydroperoxide i s one s i m i l a r t o the homogeneous decompo89 s i t i o n of methyl ides ^ 2  , ethyl,  i s o p r o p y l and t e r t - b u t y l  i n v e s t i g a t e d by K i r k and K i r k and Knox, who  hydroperoxhave found  the decomposition; process t o be ROOH  ^ RO + OH  (85)  w i t h an a c t i v a t i o n energy of about of about  10  1 4  sec  - 1  .  39 kcal/mole and an A - f a c t o r  These authors have a l s o concluded that  hydroperoxides are u n l i k e l y t o p l a y a major r o l e i n c h a i n branchi n g of the o x i d a t i o n of hydrocarbons  above 300°C.  In e x p l a i n i n g the f o r m a t i o n of products i n the o x i d a nt  t i o n of 2-butenes,  N o r r i s h and P o r t e r  have proposed a mechanism 7  i n v o l v i n g the OH r a d i c a l as the main c h a i n c a r r i e r .  The Knox  mechanism makes the same s u g g e s t i o n and i n c l u d e s a c o n v e r s i o n of HO2 t o OH.  Both p r o p o s a l s can e x p l a i n s a t i s f a c t o r i l y the  forma-  t i o n of p r o d u c t s , but would g i v e the f o l l o w i n g e x p r e s s i o n : d(Acetaldehyde) , ,~ „ . — i ' = k ( 0 ) (2-Butene) dt N  f  n  N  2  i n disagreement  with present e x p e r i m e n t a l o b s e r v a t i o n .  It i s p o s s i b l e t o d e r i v e a c h e m i c a l l y reasonable mechanism f o r the p r o d u c t i o n of acetaldehyde d u r i n g the i n d u c t i o n period.  A l l a v a i l a b l e data p o i n t t o the f a c t that the  step i s probably as f o l l o w s :  initiation  121 CH CH=CHCH 3  + 0  3  >- CH CH=CHCH  2  3  (R) + H 0  2  2  (76)  . \ CH CH-CH=CH (R) 3  2  90 Ingold. has found  , i n the l i q u i d phase, t h a t t h i s  reaction 35  i n v o l v e s an a c t i v a t i o n energy has ISiiwH^that r e a c t i o n  of about 30-35 kcal/mole. S a l o o j a  (76) i s h i g h l y  endothermic.  The b u t e n y l r a d i c a l R probably r e a c t s very r a p i d l y w i t h oxygen t o form a peroxy r a d i c a l . i n e i t h e r of the f o l l o w i n g ways: CH CH-CH=CH  + 0  2  CH CH=CHCH " + 0  2  3  3  2  2  Sleppy  T h i s r e a c t i o n may proceed  >- CH CH-CH=CH 6-0' 3  2  (A)  (81)  CH CH=CHCH 00 * (B) 3  (82)  2  and C a l v e r t , i n t h e i r f l a s h p h o t o l y s i s study of  the r e a c t i o n between methyl r a d i c a l s and oxygen  , has found the  r e a c t i o n t o be a t h i r d order one: CH  3  + 0  The value of k  g g  2  + M  CH 00' + M  (86)  3  at 25°C was found t o be 3.6 x 1 0  1 0  l mole~ sec 2  2  _ 1  92 Combining with t h e data of Hoey and Kutschke k  g 6  , an estimate of  is k  8 6  = 4.3 x 1 0  1 1 e  ~  1  4  6  0  /  R  T  l mole- sec , 2  2  - 1  It i s q u e s t i o n a b l e whether t h e b u t e n y l r a d i c a l  reaction  with oxygen i s a l s o t h i r d order, s i n c e t h e b u t e n y l r a d i c a l i s much l a r g e r than t h e methyl r a d i c a l . of t h e a c t i v a t i o n energy  In any case, t h e low value  f o r t h e methyl r a d i c a l r e a c t i o n w i t h  oxygen i n d i c a t e s t h a t the a c t i v a t i o n energy and  f o r r e a c t i o n s (81)  (82) would a l s o be very s m a l l . The  disappearance  of t h e b u t e n y l peroxy  radicals  122 probably proceeds i n one or both o f two ways: (a) R 0  2  Decomposition >- products  (87)  Abstraction (b) R0„  *- ROOH  (83)-(84)  from RH ROOH Decomposition  p r o  ducts  Norikov and Byumberg i n a study of t h e n-butane o x i d a t i o n at 250°C u s i n g an i s o t o p i c t r a c e r m e t h o d  38  have found that more  than 50% o f t h e s t a b l e r e a c t i o n products are d e r i v e d from t h e decomposition route ( a ) .  In a study of t h e mercury p h o t o s e n s i 39  t i s e d o x i d a t i o n of methane at 360°C, Kleimenov  and Nalbandyan  ,  a l s o u s i n g an i s o t o p i c t r a c e r method, have found that 90% of t h e formaldehyde  produced  i s d e r i v e d d i r e c t l y from t h e methyl  r a d i c a l and only 10% from the decomposition of methyl  peroxy  hydroper-  oxide. Thus i t i s reasonable t o p o s t u l a t e that i n the o x i d a t i o n of 2-butenes i n t h e temperature  range 289-357°C, r e a c t i o n  products are predominantly d e r i v e d from t h e decomposition route (a).  Acetaldehyde  and subsequent  i s probably produced through the i s o m e r i s a t i o n  decomposition o f t h e b u t e n y l peroxy r a d i c a l A:  CH CH-CH=CH 3  2  0-0^ CH -CHiCHCH 3  (A)  ^ CH CH-CHCH  2  (88)  ^ CH CH0 + CHgCHO  (89)  3  0—6 2  3  04-0 T h i s i s o m e r i s a t i o n - d e c o m p o s i t i o n path i s c o n s i d e r e d very t a n t by Semenov ^ and by S h t e r n . 1  1  impor-  R e a c t i o n (88) i n v o l v e s t h e  7 2 s c i s s i o n of a double bond (~ 55 kcal/mole ' *) and t h e f o r m a t i o n  of a C-0 bond (~84 kcal/mole  7  c ) and i s t h e r e f o r e exothermic.  123 R e a c t i o n (89) i n v o l v e s the breakage of a C-C bond (~80 k c a l / m o l e ) and an 0 - 0 bond (~ 40 k c a l / m o l e ) 7 5  and the f o r m a t i o n of  75  two C=0 bonds ( ~~ 2x86 k c a l / m o l e ) 94  and i s t h e r e f o r e a l s o exo-  thermic. Chauvel and h i s co-workers have shown t h a t t h e A and B b u t e n y l hydroperoxides (see page 7 3 ) .  are produced  i n equal quantities^**  Thus the c o r r e s p o n d i n g A and B b u t e n y l peroxy  r a d i c a l s must a l s o e x i s t  i n equal c o n c e n t r a t i o n s .  If the B  r a d i c a l undergoes the same i s o m e r i s a t i o n and decomposition as i n r e a c t i o n s (88) and (89), formaldehyde CH CH=CHCH 3  (B)  2  - CH CHCH-CH  2  (90)  >- HCHO + CHgCHCHO  (91)  3  0-6  0—0  CH CHCH|CH ^ O-t-0 3  would be produced:  2  If these r e a c t i o n s are important, the c o n c e n t r a t i o n s of f o r m a l dehyde and p r o p a n a l would be n e a r l y equal and would be about h a l f of the acetaldehyde c o n c e n t r a t i o n .  No formaldehyde has  been d e t e c t e d d u r i n g the i n d u c t i o n p e r i o d and propanal has appeared  i n a much s m a l l e r c o n c e n t r a t i o n than  acetaldehyde.  Under the present experimental c o n d i t i o n s , t h e B b u t e n y l peroxy r a d i c a l i s t h e r e f o r e l i k e l y t o undergo an i s o m e r i s a t i o n t o t h e A form: CH CH=CHCH 3  (B)  2  0—0 CH CH-CH-CH 3  ^O-O^"  2  ^ CH CH-CH-CH 0—0 3  =v. CH CHCH=CH 3  2  2  (A)  (92) (93)  0-0 •  The CHgCHO r a d i c a l produced  i n reaction  a b s t r a c t s a hydrogen from 2-butene t o form another  (89) probably acetaldehyde  124 molecule: CH CHO + CH CH=CHCH 2  The  3  »- CHgCHO + R  3  (94)  a c t i v a t i o n energy f o r t h i s r e a c t i o n should be s i m i l a r t o  that of t h e e t h y l r a d i c a l a b s t r a c t i o n of «• -hydrogen from an 47  o l e f i n , that  i s , about 9 kcal/mole  . Propanal i s probably  produced when the CHgCHO r a d i c a l r e a c t s with a methyl r a d i c a l , the f o r m a t i o n o f which w i l l be d i s c u s s e d i CH  3  + CH CHO  later:  *- CH CH CHO  2  3  (95)  2  In a d d i t i o n t o r e a c t i n g w i t h oxygen, t h e b u t e n y l r a d i c a l i s a l s o capable of a b s t r a c t i o n of ^-hydrogen from 2-butene and of a d d i t i o n t o t h e double bond of 2-butene: R + CH CH=CHCH  3  R + CH CH=CHCH  3  3  3  ^ 2-butene + R  (96)  ^ CHgCH-CHCHg  (97)  R In a study of the r e a c t i o n s between the CD and  butene isomers, McNesby! and Gordon  resonance s t a b i l i s e d b u t e n y l  3  gation, r e a c t i o n reaction  radical  have shown that t h e  r a d i c a l R i s reluctant t o abstract  hydrogen at 375°C but does so r e a d i l y at 500°C. the experimental c o n d i t i o n s  3  Thus, under  (289-357°C) i n t h e present  (96) i s probably unimportant.  investi-  However,  (97) i s u n l i k e l y t o be important e i t h e r due t o t h e  lack of evidence f o r p o l y m e r i s a t i o n . r a d i c a l produced i n r e a c t i o n CH fCH-CH-CH 3  3  (97) CH  However, t h e o c t e n y l  i s l i k e l y t o undergo s c i s s i o n : 3  + R-CH=CHCH  3  (98)  R T h i s r a d i c a l can a l s o r e a c t w i t h oxygen t o give products i n the same ways as t h e i n i t i a l b u t e n y l  radical.  125 Peroxy r a d i c a l s are known t o be able t o add t o o l e f i n i c 48  double bonds i n the l i q u i d phase  and can be expected t o do t h e  same i n t h e gas phase: R0  + CH CH=CHCH  2  3  CH -CH-CHCH 3  ^CH CH-CHCH 00R  3  3  (99)  3  CHg + ROOCH=CHCH  3  (100)  3  OCR Reactions (96)-(100) are probably unimportant during t h e i n d u c t i o n p e r i o d s i n c e no peroxide or methanol  (from the methyl  r a d i c a l r e a c t i o n w i t h oxygen) was detected. The methyl r a d i c a l s produced i n r e a c t i o n s (100) can undergo r e a c t i o n s s i m i l a r t o r e a c t i o n s CH  3  + CH CH=CHCH  CH  3  +. CH CH=CHCH  3  3  ^ CH  3  4  (98)  (96)and (97):  + R  (101)  >• 3^CH-CHCH CH  (102)  CH  3  and  3  3  Reaction and S t e a c i e k  (101) has been s t u d i e d by Trotman-Dickenson  who have found t h a t  7 6  = 7.6xl0  1 Q 1  6 e  -  7  7  0  0  /  R  1  T  aole-W . 1  The r a t e constant f o r t h e methyl r a d i c a l a b s t r a c t i o n of -hydrogen from propylene, found by t h e same authors'> ' , u  3.0xl0 T^ 6  600°K).  e  "  7  7  0  0  /  R  T  1 mole~ sec" (= 1  1  1.3xl0  5  is  1 m o l e " s e c ~ at 1  1  The methyl r a d i c a l a d d i t i o n t o propylene has been 93  s t u d i e d by Mandelcorn and S t e a c i e  . T h e i r r e s u l t s can be i n t e r -  p r e t e d t o give the r a t e constant t o be 1.8xl0 T2 ~6000/RT 5  e  1 mole" sec~ (= 1  1  1.2xl0  5  1 mole  r a d i c a l r e a c t i o n s w i t h 2-butene reaction  _ 1  sec  - 1  at 600°K).  Thus i f methyl  and propylene are s i m i l a r ,  (102) s h o u l d proceed as f a s t  as r e a c t i o n (101) . In  126 f a c t , only t r a c e amounts of methane have been found d u r i n g t h e i n d u c t i o n p e r i o d i n the present  study.  Therefore,  the methyl r a d i c a l a d d i t i o n t o 2-butene, should McNesby and G o r d o n  4 9  + CHoCH=CHCH„ 3  3  be unimportant.  have found that t h e f o l l o w i n g  displacement r e a c t i o n process i s very  CDo  r e a c t i o n (102),  important  at about  400°C:  CH ^ ^CH-CH-CHo CD ^ 3  3  '  CH  r  + Butene isomers  (103)  —*  The  decomposition of the p e n t a n y l  (102)  r a d i c a l produced i n r e a c t i o n  would give r i s e t o butene isomers as p r e d i c t e d by r e a c t i o n  (103) : CHo , ^CH-CH-CH CH  ^ CHg + CH CH=CHCH  3  3  3  (cis-trans  CH_ ^s.. . ^CH-CH-tCH  ^ CH  +  (104)  3  isomerisation)  CHo ^C=CH  (105)  2  In f a c t , both c i s - t r a n s i s o m e r i s a t i o n and i s o m e r i s a t i o n t o isobutene: have been observed i n t h e present The  pentanyl  study.  r a d i c a l produced i n r e a c t i o n (102)  is  l i k e l y t o r e a c t q u i c k l y w i t h oxygen:  CH  . ^CH-CHCH + 0  3  3  C H  3  2  3  ^CH-CHCH 3 0-0  CHq >"CH  6-6  3 3  C H  CHq ^CH-CHCHo C H  CH ^  C H /  CHCH„  ^0-0'  7 5  is therefore s l i g h t l y  (107)  6  T h i s r e a c t i o n i n v o l v e s t h e s c i s s i o n o f a C-C bond (—80 m o l e ) and t h e formation  (106)  kcal/  of a C-0 bond ( ~ 84 k c a l / m o l e ) and  endothernriic.  7 5  127 The r a d i c a l produced  i n reaction  (104) i s probably  capable o f undergoing decomposition t o g i v e a methyl  radical  and two acetaldehyde molecules: CRo CH-O-O-CHCHo  x  >• CHo + 2CHoCH0 3 3  3  CH ^ 3  (108)  T h i s r e a c t i o n i n v o l v e s t h e s c i s s i o n of a C-C bond ( ~* 81 k c a l / mole ^) and an 0-0 bond ( — 84 k c a l / m o l e ^ ) 7  7  two G=0 bonds (-~- 2x86 k c a l / m o l e ) 94  The produced  and the formation of  and i s s l i g h t l y  i s o m e r i s a t i o n of t h e 2-pentanyl peroxy  i n r e a c t i o n (103) can take a d i f f e r e n t  CHo CH 3  exothermic. radical  route:  CHo ^CH-CH-CHo  C H  I  3-  CW  t  0 -0'  Utl  CHo i ^CH-CH-0|0-CH CH i 3  Reaction (110)  ^CH-CH-0-O-CHo  (109)  3 CH_ ^ ^CHCH0 + CH 0' ^^3  (110)  J  3  3  i s exothermic t o the extent of 88 k c a l / m o l e . 1  Shtern^" has p o s t u l a t e d t h a t r e a c t i o n s (102), (106)-(110) be important i n the gas phase o x i d a t i o n o f o l e f i n s . shown i n the present study, at l e a s t  would  I t has been  d u r i n g the i n d u c t i o n p e r i o d ,  that t h i s i s not so. The r o l e of acetaldehyde i n c h a i n branching i n the 17-20 o x i d a t i o n of propylene, has been w e l l demonstrated . Blundell 21 23 and Skirrow and N o r r i s h and P o r t e r have shown the same r o l e f o r acetaldehyde i n the o x i d a t i o n of 2-butene.  In the present  study, acetaldehyde has been found t o be the major product d u r i n g the i n d u c t i o n p e r i o d .  Thus t h e f a c t that acetaldehyde i s  r e s p o n s i b l e f o r c h a i n branching i n the o x i d a t i o n o f 2-butenes is clearly established.  However, i t has been shown i n F i g . 37  128 (page 115) that the i n d u c t i o n p e r i o d does not t e r m i n a t e when a c e r t a i n minimum c o n c e n t r a t i o n lated.  On the other  hand, t h e r e  simply  of acetaldehyde i s accumu-  i s a p o s s i b i l i t y that the rate  law which governs the p r o d u c t i o n  of acetaldehyde at the very  i n i t i a l stages of the o x i d a t i o n of 2-butene does not apply towards the end of t h e i n d u c t i o n p e r i o d , but changes i n such a way t h a t at t h e end of the i n d u c t i o n p e r i o d , concentration  a c e r t a i n minimum  of acetaldehyde i s n e v e r t h e l e s s  is difficult  accumulated.  It  t o determine whether t h i s i s t h e a c t u a l s i t u a t i o n .  In any case, t h e mechanism of the o x i d a t i o n of a c e t a l dehyde has been w e l l e l u c i d a t e d , mainly by a s e r i e s of i n v e s t i g a t i o n s by McDowell and h i s co-workers.  T h i s has been e s t a b l i s h -  26 ed  t o be as f o l l o w s : CHgCHO + 0  2  ^CH CQ + H 0  2  >CH C  3  (10)  2  0  + 0  CH CO 3  (11)  3  0 0  x  ^0  CH C  :  3  x  x  + CH3CHO-  X  ^CH C 3  0 0 H  0  .  3  + OH  V  (13)  . 0 '  ^0  2CH C^  (12)  OOH  x  3  + CH3CO  3  00>  CH C^  o  >- CH C '  ^ 0  ^CH C—0-0-C 3  CH  3  + 0  2  (14)  00  In the case o f c h a i n b r a n c h i n g d u r i n g the o x i d a t i o n of 2-butenes, the  i n i t i a t i o n step of the o x i d a t i o n of acetaldehyde probably  includes the f o l l o w i n g r e a c t i o n : CH3CHO + R a d i c a l  a- C H 3 C O  (111)  Moreover, the a b s t r a c t i o n of hydrogen by t h e p e r a c e t y l r a d i c a l ,  129 reaction  (12), may be made from the parent 2-butene. The p r e s e n t l y proposed mechanism f o r the p r o d u c t i o n  of acetaldehyde d u r i n g the i n d u c t i o n p e r i o d i n the o x i d a t i o n of 2-butenes i n v o l v e s r e a c t i o n (91)-(93)  (76) , (81), (82), (87), (88)  and  l i s t e d below:  CH CH=CHCH 3  + 0  3  CH CH=CHCH (R)  -  2  3  2  .1  CH CH-CH=CH  2  (R)  CH CH-CH=CH  2  (A)  3  CH CH-CH=CH 3  +  2  0  3  2  +  H0  (76)  2  (81)  00" CH CH=CHCH 3  CH CH-CH=CH 3  0- 0  + 0  2  2  -5- C H C H = C H C H 0 0  -  3  (87)  0—0  :  |,'l  (88)  CH CH0 + CH CH0  CHoCH+CHCHo 3  (82)  (B)  CHqCH-CH-CHo  (A) -  2  2  2  3  2  o-i-o C H o C H = C H C H  f  J  |  0  •  -^CHoCHCHCH  (B)  \ / 0-0  0-0  CH CH-CH=CH  CHqCH—CH—CHo  3  \  (92)  2  oo-  0—0 CH CH0 + C H C H - C H C H 3  2  (91)  9  (93)  •*» CH CH0 + R 3  3  T h i s scheme must be incomplete because  t h e r a t e law d e r i v e d  from t h i s mechanism, employing t h e s t a t i o n a r y s t a t e  treatment,  is d(Acetaldehyde) dt which  constant x  i s i n disagreement d(Acetaldehyde) dt  (2-Butene)(0 ) 2  with the experimental observation  = k  a  (2-Butene)  (0 ) o  a  (110)  130 If i t i s assumed t h a t the acetaldehyde s o l e l y through the hydroperoxide  route  i s derived  (page 122), which i s  21  favoured by B l u n d e l l and Skirrow  , the r a t e law f o r  acetaldehyde  f o r m a t i o n would be as f o l l o w s : d(Acetaldehyde) —dt  , , _, . v ~l\ . i constant x (2-Butene) ( 0 ) /  =  N  tr  o  which i s again i n disagreement t i o n , e q u a t i o n (110)  0  w i t h the experimental  observa-  above.  If r e a c t i o n s (98) and (99) are c o n s i d e r e d t o be the propagation s t e p s R0  2  + CH CH=CHCH 3  3  ^ CH CH-CHCH 3  (98)  3  OOR CH -CH-CH-CH 3  ^CH  3  3  + ROOCH=CHCH  (99)  3  OOR the d e r i v e d r a t e law would be as f o l l o w s : d(Acetaldehyde) — — dt  , . _ , 2, = constant x (2-Butene) ( 0 ) • «  S e v e r a l other hypotheses  /  0  N  A N  o  have been attempted  but, as above, the  d e r i v e d r a t e laws do not agree with the experimental  observa-  tion;. There i s a p o s s i b i l i t y t h a t the experimental r a t e law, e x p r e s s i o n (110) above, may c o n s i s t of a term a t h i r d body c o n c e n t r a t i o n . it  With data a v a i l a b l e at p r e s e n t ,  i s not p o s s i b l e t o v e r i f y t h i s p o s s i b i l i t y .  investigations w i l l certainly  involving  Further  be needed i n order t o e s t a b l i s h  the primary c h a i n process r e s p o n s i b l e f o r t h e p r o d u c t i o n of acetaldehyde  (and, f o r t h a t matter,  degenerate  c h a i n branching  131 agents i n other  o x i d a t i o n systems) d u r i n g the i n d u c t i o n  i n the o x i d a t i o n of 2-butenes.  period  132 REFERENCES 1.  V. Y a . S h t e r n , The Gas Phase O x i d a t i o n of .Hydrocarbons, t r a n s l a t e d by B.P. M u l l i n s , Pergamon, 1964.  2.  G. J . Minkoff and C. F. H. T i p p e r . Chemistry of Combustion Reactions, Butterworths, 1962.  3.  B. 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Chem., 43, 2236 (1965). 90.  K. U. Ingold, J . I n s t . P e t r o l . , 45, 244 (1959).  91.  W. C. Sleppy and J . G. C a l v e r t , J . Am. Chem. S o c , 81, 769 (1959).  92.  G. R. Hoey and K. 0. Kutschke, Can. J . Chem., 33, 496 (1953).  93.  L. Mandelcorn  94.  L. P a u l i n g , the Nature of the Chemical Bond, 3 r d ed., C o r n e l l U n i v e r s i t y P r e s s , 1960.  and E. W. R. S t e a c i e , i b i d . ,  32, 474 (1954).  137 APPENDIX I R e s u l t s of the R e a c t i o n Between 0-atomsj and  cjs-2-butene  Nomenclature .1. 2. 3. .4. 5. 6. 7. 8. 9  -  Run No . N flowrate i n umole/min. 0-atom f l o w r a t e = NO f l o w r a t e i n umole/min. 2-Butene f l o w r a t e i n /Amole/min. T o t a l p r e s s u r e i n mm Hg. L i n e a r v e l o c i t y i n cm/sec. (0)^ i n gm-atom/1 (2-Butene)i i n mole/1. 2  ( 0 ) i  /(2-Butene)i  x 100  10.  A % ( ( ) (2-Butene)i  11. 12. 13. 14. 15. 16. 17. 18. 19. 20. 21. 22. 23. 24. 25. 26. 27. 28. 29.  A % of Propane. A % of Isobutane. A % of 2-Butene. A % of X 4 . 2 A % of acetaldehyde. A % of X . A % of P r o p a n a l . A % of cis-2,3-butene o x i d e . A.% of acetone. A% of trans-2,3-butene o x i d e . A % of I s o b u t a n a l . A % of Butanone. A % of B i a c e t y l . A % of X 3 3 A % of X A % of T o t a l p e r o x i d e s . A % of c i s - t r a n s i s o m e r i s a t i o n . A % of carbon d i o x i d e . A.% o f oxygenated p r o d u c t s .  P r o d u c t  6  3 8  0  x  1 0  0)  of methane, ethane,  ethylene.  138  Item  Run  1. 31 38 32 34 36 33 35 37 2. 336 375 340 360 368 369 345 362 1 .7 3. 2 .6 2 .5 3 .0 2 .8 2 .8 2 .5 2 .5 4. 36 .2 5 .0 7 .0 15 36 25 .5 10 7,.3 1 .09 0,.97 1 .01 5. 0 .85 0 .95 . 0 .93 , 0 .82 0 !95 6. 57 .4 54 .5 56 ,5 56 .0 54 .4 56 .0 55,.2 57 .2 8. 5 .53 1 .35 1,,97 1 .04 2,.31 3 . 15 4 .7 42,.9 18,,7 7 .2 10 9. 50 28 34 .2 1 .08 1,.38 1,.4 1,.51 10 . 3 .6 3. 1 0 .49 12 .3 3 .32 1,.92 1,.8 2,.56 1 .09 11. 4 .2 4 .9 10 .6 0 .90 12. 1 .2 0 .60 , 0 .80 , 4 .9 0 .83 0 .37 2 .3 13. -14,.7 -6 .50 -26 .4 - 9 .9 - 9 .44 - 3 .64 -10 .38 -43 .5 15. 1,,04 0 .75 0,.26 1 .87 0 .89 , 3 .2 0 .39 0 .034 16. 0 .26 0,.25 1 .20 0,.30 0 .36 0,.65 0 .55 17 . 0 .93 1,.43 1 .36 1,.07 0 .98 0 .42 0,.59 4 .16 0 .068 18. 0 . 10 0 .077 0,. 18 0 ., 11 0 .27 0, 28 0 . 19 0 .33 19. 0 .33 , 1,.0 0 .36 0 . 15 0 .60 0 .71 0 .60 , 0 . 14 20. 0 .68 1 .16 1,.40 0 . 10 0 .057 0 .22 2 .34 1 .37 21. 1 . 13 0 .80 0 .36 0 .527 0 . 14 0 .960 1 .20 2 .07 0 .90 0 .414 22. C O .750 0 .263 0 .950 0 .057 23. 0 .0033 0 .015 0 .016 0 .097 24. 0 .0155 0 .010 C O . 100 0 .928 0,,059 0 .335 0 .236 25. 0 ., 14 1,.00 0 .0147 0 .018 2 .67 4 .8 29. 4 .2 1 .7 5,,0 2 .3 14 .9 5 .6 15 . 1  139  Item  Run  1. 39 41 46 40 43 45 42 44 337 367 360 2. 360 375 392 360 309 3. 1 .8 1 .6 1 .8 1 .6 2 .0 1 .9 1,.9 2 .0 4. 51 36 115 196 370 35 78 300 5. 1 . 10 1 . 13 1,.33 1 .59 1 . 16 1 .48 1 .00 1 .05 6. 51 .2 56.,0 51 ,9 57 .6 57 .8 56 .4 60 .7 55 .0 ^8. 7 .31 4,,72 11 . 1 14 .7 24 .9 44 .8 39 .1 4 .68 9. 3 .5 2 .6 1 .7 0 .82 0 .43 5 .3 0 .60 5 .4 00 . 18 10. 0 .37 0 .88 0 .54 0,,87 0 .79 0 .52 0 .57 1 .3 2 .7 2 .3 11. 1 .0 2 .4 1 .64 1 .06 1 .41 1. 1 0 .95 12. 0 .58 1 .0 0 .67 0 .54 0 .018 0 .51 13. -5 .06 -8,.04 -5,.08 -7 .36 -3 . 11 -3 .17 -4 .22 -8 .52 15. 0 .083 0 .052 0 .071 0 .083 , 0 .041 0 .0078 0 .028 16. 0 .011 0 .020 0 .23 0 .19 0 .097 0 .013 0 .23 0,.38 17 . CO .441 0 .634 0 .708 0 .59 0 .23 0 .34 0 .479 0 .849 18. 0 .017 0 .012 0 . 19 0 0 .064 0,.014 0 .725 19. 0 . 17 0 .26 0,. 16 0 .075 0 . 11 0 . 148 0,.40 20. 1 .54 0 . 14 1 .31 0,. 14 0 .068 0 .016 0 .257 1,. 13 21. 0..91 1,.01 10 .37 0 .17 1 .02 0 .548 0 ,92 0 .280 0 .391 0,.836 22. 0,.626 0 . 13 23. 0,.085 0 .29 .0186 0C0633 0 .0539 24. 0 .0292 , 0.,034 0 .0206 0 .0369 0 0 .018 25. 0.,058 0, 030 0 .0467 0 .0382 0 .0942 0 .0310 0,. 160 0,.0791 29. 4 .0 2 .6 2..7 1 .0 1 .5 2 .3 0 .92 3,.6  140  Item  Run  1. 47 48 2. 386 290 3. 1 .9 2.,0 4. 101 22 5. 1 . 10 0. 98 6. 60 .7 57 .8  49 400 2. 7 10 0 .93 60 .8  50 386 2 .8 15 0 .90 61.5  51 380 2. 4 19 0 .93 58.4  77 .  8. 9. 10 . 11. 12. 13. 15. 16. 17 . 18. 19. 20. 21. 22. 23. 24. 25. 29.  1. 3 12 .2 2. 8 1 .9 27 9. 1 0 .86 3. 16 0 .61 2 .9 3. 0 3. 61 1 .4 1.6 0. 24 -8 . 13 -10. 83 -15. 43 0 .014 2. 81 0 .19 0. 200 0. 26 1. 53 1.35 0 .77 0. 017 0. 173 0 .40 . 0. 431 0. 53 1.06 0..735 1.66 1. 47 0,.841 1. 24 0. 944 0 .020 0. 11 0 ,0286 . 0 .084 0. 136 0..0496 0. 346 0 .111 2 .8 8. 2 5.4  1 .8 2. 4 18 :-6, 12. 6 1 .62 1. 17 1. 59 2 .52 0 .29 0 .19 -8 .76 -10. 21 0 .51 2. 27 0 .27 0 .049 1. I 1. 11 0 .067 0. 067 0 .530 0. 42 0 .792 0. 40 1.08 0 .787 1. 10 0 . 136 0. 26 0 .0864 0 .253 0 .220 0. 560 4. 1 7 .2  66 64 65 692 1030 1332 4 .2 5 .0 17 . 24 40 42 1.. 10 0 .80 0 .95 126 174 152 0..24 0 .24 0 .72 . 1.. 16 1..69 2..4 42..5 10 21 1..2 1..6 2 .0 2 .0 2 .8 2 .7 1.. 1 0 .78 1.. 2 -5..63 -7 .86 , -8..51 0 .40 . 0 .25 . 0 .37 . 0 .19 0., 15 0..018 0 .54 0 .60 . 0 .98 . 0 . 11 0 .035 0 .073 , 0 .17 , 0., 15 0,. 13 0,.13 0.. 16 0..230 0 .057 . 0..21 0..222 0 .388 0..017 0..014 0.. 13 0 .073 . 0,.093 0 . 109 0. , 128 0 . 168 0.. 186 1..5 1..7 2., 1  141  Item  Run  68 69 1. 67 70 73 74 75 72 2. 1690 1360 1057 538 900 747 952 757 3 . 16 .3 15 .4 12 . 1 6 .0 8 .9 11 .4 9 .2 7. 1 4. 45 45 40 40 42 50 49 35 5. 1 .28 1 . 15 0 .99 0 .90 0 .85 0 .67 0 .65 0 .56 6. 188 170 154 144 129 208 172 143 7. 0 .64 0 .67 0 .58 0 .31 0 .51 0 .39 0 .39 0 .37 8. 1 .8 1,.9 1 .9 2 .0 2 .4 1 .8 1 .8 9. 36 34 30 15 21 23 19 20 10 . 2 .5 1..3 2 .7 1 .9 1 .8 1..5 2 .0 2 .3 11. 3 .4 2 .0 3 .2 2. 5 3 .0 4 .0 3 .0 2 .9 1 .4 12. 0..81 0 .86 1. 1 1 .2 0 .73 0 .78 0 .53 13 . -10 .70 -6..96 -10 .85 -8 .76 -8 .24 -8..08 -7 .52 -10 .26 15. 0 .67 1,.3 0..36 0.,53 0 .61 0 .40 0,.40 0 .21 16. 0 .074 , 0 .29 0 .16 17 . 1.. 14 0,,68 1 .18 0.,839 0,.589 1 .01 0 .41 0 .799 18. 0 ., 14 0.,075 \ .058 0,,39 0 .082 0 . 12 0 .049 0 .090 19. 0 .29 , 0., 18 \ 0,.38 0 ,21 , 0 . 18 0 . 12 0 .22 0 .21 -20. 0 .0076 . 0.,27 0 ., 15 0 .13 . 0,. 18 0,.057 0..238 0..252 21. 0.. 16 0 .278 , 22. 0.,415 0. 557 0 .496 0 ,380 . 0 .321 , 0 .338 0 .285 . 0 . 186 23. 0 .016 . 0.022 0..052 0 .016 , 0.,017 0..016 0 .029 . 0..033 24. 0 ,. 159 0. 186 0.. 129 0., 124 0..045 0..030 0 . 105 0 .072 . 25. 0 .247 . 0 ,298 . 0..302 0.,240 0,.078 0.. 163 0.. 114 0,.044 29. 3. 3 2.9 4., 1 2..9 2,,6 2 .6 2..4 2..8 0  142  Item 1. 2. 3. 4. 5. 6. 7. 8. 9. 10 . 11. 12. 13 . 15. 16. 17 . 18. 19. 20. 21. 22. 23. 24. 25. 29.  Run 76 76A 77 78 79 82 80 347 336 250 179 146 148 141 4 .2 4 .2 1. 1 2 .5 1 .0 1. 1 2. 1 38 39 42 33 39 36 40 0 .41 0 .40 0 .40 0 .29 0 .27 0 .24 0 .39 130 130 101 109 106 66 .2 84 .0 0 .24 0 . 24 0 . 18 0 . 14 0 .069 0 . 12 0 .096 2. 1 2 .2 3 .0 2 .2 2 .7 11 11 6 .0 6 .4 2 .8 3. 1 2 .6 1 .3 1. 1 1 .5 1.2 1 .3 : . i : ^5 1..4 2 .8 2 .3 1 .8 2. 1 2. 1 1 .9 2 .0 0 .34 0..35 0 .21 0 .18 , 0 . 13 0 .18 0 .20 -5 .86 -4 .70 -6 .30 -4 .61 -4 .94 -3 .97 -4 .92 0 .58 0 .35 0 .29 0 .21 0..30 0 . 17 0 .48 0 . 11 0 . 19 0 .09 0 .070 0 . 14 0 .072 0 .36 0 .35 0 .41 6 .20 0 . 19 0 . 19 0 . 18 0 . 19 0 .092 0 .076 0 .049 .088 .063 .048 0 .046 0 0 6. 0 . 15 0 .087 0 . 11 . 116 . 16 0 .041 0 0 .033 6. 0 .070 0 .088 0 .059 0 .206 0..242 0 . 13 0 .0875 0 . 13 0 .089 0 . 12 0 .228 0 .258 0 .166 0,. 183 0 . 146 0 . 197 0 . 131 0 .011 0 .012 0 .019 0 .0085 0..016 0 .020 0 .029 0 .026 0,.024 0 .018 0 .015 0,,021 0 .032 0 .019 0 .0529 0,.0520 0 .031 0 .0504 0 .059 0.0347 0.0290 1 .6 1 .0 1.,0 1. 1 0 .82 1..6 2 .2  83 96 1 .0 40 0,. 19 98 .8 0 .074 2 .5 1,. 1 2 .8 0 .28 , -5..00 0 .084 0 . 16 0 . 142 0 .051 0 .018 0 .051 0 .083 0.. 139 0 .0069 0 .018 0 .054 0 .66  143  Item 1. 2. 3. 4. 5. 6. 7 . 9. 10. 11. 12. 13. 15. 16. 17 . 18. 19. 20. 21. 22. 23. 24. 25. 29.  Run 84 34 1 38 0 67 0 2 2 4 0 -8 0 0 0 0 0 0 0 0 0 0 1  . 15 . 1 . 11 .6 .3 .5 .29 .26 .36 . 15 .113 .038 .16  85 62 0 40 0 93 0 1 2 5 0 -8 0 0 0 0 0  .088 . 163 .025 .017 .034 .0  0 0 0 0 0 0  .0  .6 . 15 .4 .047 .5 . 1 . 1 .41 .53 . 18 . 13 . 12 .023 .096 .047 .134 .0068 .016 .048 .78  86 105 0 49 0 111 0 0 1 2 0 -4 0 0 0 0 0  87 162 .4 0 35 . 19 0 112 .027 0 2 .82 1 . 1 .8 2 0 .20 -4 .85 0 .23 0 .039 .14 0 .062 0 .090 0 0 0 .064 0 0 . 114 0 0 0 .013 0 .015 0 0 0 .026 0 .56 0  88 89 107 200 .70 1..0 0 .5 39 35 .24 0 .. 2 7 0 .18 119 100 .046 0 ,. 0 6 8 0 .037 1 .3 .0 2 .9 .2 1 .3 1..4 . 1 2 .4 3 . 1 . 19 0 .25 0 .31 .33 -6 . 1 1 - 5 .. 4 5 .23 0 ,. 4 4 0 .34 .046 0 .065 0 .062 0 .24 . 150 0.. 2 6 .070 0 .086 0 .093 .027 0 .. 1 4 0 0 . 16 .049 0 . 12 .093 0 . 115 . 119 0 .218 0.. 2 0 4 .014 0 .041 0 .025 .015 0 ,. 0 2 8 0 .035 .024 0 .051 0 .063 1 .3 .82 1..4  91 154 .1,.0 35 0 .22 118 0 .062 2 .9 1 . 1 2 . 1 0 ,. 1 8 -4 .49 0 .24 0 .089 0 .210 0 .095 0 .029 0 .084 0 . 119 0 . 118 0 . 163 0 . 126 0 .018 0 .015 0 .020 0 .014 0T044 0 .030 1 .0 0 .83  90 130 0,.4 34 0 .. 2 0 112 0 .026 1,.2 1 .3 2 .9 0.. 1 8 - 5 .24 0 .25 0 .054 0.. 1 5 0.. 0 8 0 0.. 0 3 0  144  cis-trans  Item 1. 2. 3. 4. 5. 6. 7. 8. 9. 27 .  Isomerisation  Run 158 159 865 1170 16 25 59 56 0. .66 0 .69 194 247 0..61 0 .75 2. 3 1..7 27 45 0..446% 1,.02  161 452 10 40 0. .40 171 0..41 1.,7 25 0..525  162 163 125 2160 4 .0 33 .3 40 80 0 .20 1..02 115 302 0 .24 0 .81 2 .0 2..4 10 42 0..360 .479 0,  164 270 6 .3 50 .32 0. 138 0. 33 2.,6 13 0, .699  APPENDIX II Dependence Run  log(0)  on (O) ± f o r the Reaction Between O-ratoms and cis-2-butene l o g (_.%)  i  . c i s - . CH4,C2Hg i»- A c e t a l ^ cisAcetone & Butene and C 2 H 4 Propane Butane dehyde Propanal oxide Acetone t r a n s - o x i d e 82 80 78 77 76A 76 75 74 73 72 70 69 67 68 66 65 64  -7 .016 -6 .914 -6 .848 -6 .740 -6 .625 -6 .625 -6 .436 -6 .406 -6 .414 -6..295 -6 .514 -6 .238 -6.. 196 -6.. 177 -6.. 144 -6..618 -6 .612  Order (n)  Note:  0 .599 0 .692 0 .694 0 .672 0 .768 0 .800 0 .808 0 .916 1 .011 0 .876 0 .943 1 .036 1 .030 0 .843 0 .930 0 .896 0 .750  0 .030 0 . 114 0 . 162 0 . 100 0 . 132 0 . 163 0 . 173 0 .250 0 .369 0 .276 0 .308 0 .431 0 .389 0 .099 0 .306 0 . 198 0 .060  0 .260 0 .286 0 .320 0 .326 0 .370 0 .442 0 .467 0 .478 0 .604 0 .405 0..483 0..501 0.. 534 0 .291 0..430 0..454 0..308  -0 .745 -0 .710 -0 .742 -0 .670 -0 .451 -0 .474 -0 . 176 -0 .108 0 .078 -0 . 140 P .031 -0 .066 "0 . 155 -0 .092 CO .022 0 .064 -0 . 110  -0 .682 -0 .322 -0 .523 -0 .538 -0 .457 -0 .235 -0 .684 -0 .396 -0 .398 -0 .214 -0 .274  -0 .745 -0 .726 -0 .695 -0 .724 -0 .385 -0 .458 -0 .386 -0 .098 0 .005 -0 .230 -0 .076 — 0 .072 -0 . 174 0 .056 -0 .441 -0 .168 -0 .398 0 .008 -0 .427 -0 .226 -0 .604 -0 .269  -1 .337 -1..324 -1 .056 -1,.308 -1 . 118 -1..036 -1,.045 -1,.310 -0 .910 , -1,.084 -1..411 -1..235 -0 .845 , -1.. 123 -0 .947 , -1.. 136 -1..456  -1..386 —  -1..477 —  -1..062 •— — —  -0..750 — —  -0..534 —  -0. 883 —  -  -0 .006 -0 .808 -0 .916 -0 .949 -0 .806 -0 .831 -0 .921 -0 .674 -0 .654 -0 .577 -0 .676 -0 .415 -0 .523 -0 .750 -0 .530 -0 .833 -0 .780  0 .22+0.08 0 .33+0.15 0 . 50+0 .10 0.41+0. 07 0 .25+0.14 0.31+0.08 0.98+0.17 0.96+0.13 0.92+0.21 l o g ( A % ) = log( ^ (2-Butene)i r  o  d  u  c  t  J  x  100)  146 log ( A % ) Run  logCO)-^  82 80 78 77 76A 76 75 74 73 72 70 69 67 68 66 65 64  -7 .016 . -6 .914 -6 .848 -6 .740 -6 .625 -6 .625 -6 .436 -6 .406 -6 .414 -6 .295 -6 .514 -6 .238 -6 . 196 -6 .177 -6:.144 -6 .618 -6..612  0 Order  transOxide  IsoBut anb u t a n a l one  -1..229  -1 .058 -0 .922 -0 .892 -0 .882 -0 .616 -0 .686 -0 .745 -0 .599 -0 .623 -0 .556 -0 .886 -0 .820 -0 .800 -0 .562 -0 .638 -1 .244 -0 :886  _  -1 .056 —  -1 . 157 — — —  _  -1 .245 —  _ — —  -0 .785 _ —  -0 .883 -0 .706 -0 .738 -0 .780 -0 .588 -0 :642 -0 .730 -0 .545 -0 .471 -0 .494 -0 .420 -0 .304 -0 .382 -0 .254 -0 .412 -0 .654 -0 .674  Biacetyl  -2. 066 -1. 548 -1. 8^10 -1. 728 -1. 906 -1. 955 -1. 793 -1. 482 -1. 542 -1. 807 -1. 667 -1. 286 -1. 807 -i: 650 - l . 873 - l . 860 - l . 782  X  x 3 5  -1 .812 -1 .714 -1 .680 -1 .750 -1 .618 -1 .578 -1 .524 -1 . 141 -0 .981 -1 .352 -0 .906 -0 .888 -0 .800 -0 .730 -0 .962 -1 .032 -1 . 134  38  -1..538 -1..460 -1..298 -1,. 506 --1,.284 -1..276 -1 .355 -0 .941 -0 .787 -1 . 106 -0 .620 -0 .520 -0 .607 -0 .526 -0 .730 -0 .775 -0 .891  1.15+0.21 0.27+0.25 0.59+0.08 1.06±0.22 " 0.42+0.14 " 0.25+0.18  APPENDIX I I I Dependence on ( c i s - 2 - b u t e n e ) ^ f o r the Reaction Between 0-atoms and c i s - 2 - b u t e n e  log Run 51 50 49 48 47 46 45 44 43 42 41 40 39 38 37 36 35 34 33  log(c-Bu)  i  1 .010 0 .943 1 . 189 1 .035 0 .910 0 .905 0 .931 0 .625 0 .502 0 .493 0 .867 0 .706 0 .705 1 .016 0 .561 0 .975 1 .752 1 .004 1 .422  -5 .622 -5 .747 -5,.896 -5 .553 -4..914 -4..956 -5..326 -5,.330 -4..349 -4..408 - 4 . .604 - 4 . .833 -5 . 136 -5,.257 -5 .502 -5,.636 -6 .000 -5..706 -5..870 Order  cisButene-2  4' 2 6 and C2H4  Propane  0 .068 0 .210 0 .560 -0.218 -070677 -0.104 -0.063 -a. 240 -0.264 -0.284 -0 .054 -0 .745 -0.432 CO.033 -0.312 0 .179 1.090 0 .152 0 .497  0 .201 0 .401 0 .558 0 .471 0 .464 0 .365 0 .440 0 . 150 0 .024 0 .215 0 .373 0 .004 0 . 120 0 .521 , 0 .036 0 .408 1,.026 0 .253 0 .688  C H  C  H  (n) (a) 0 . 7 1 ± 0 . 0 8 0.99+0.11 (b)-0.74+0.36  Note  (a) (b)  -  0 .356 -0 .292 0 .448  —  0 . 190 0 . 132 -0 .023 0 .029 -0 .290 -0 .264 —  -0 : 176 0 .013 -0 .236 -0 .046 -0 .427 -0 .081 —  -0 .097 —  Xg Q  -0 -0 -0 -0  —  -1 .854 —  -1 .084 -1 .146 -1 :556 -2 . 108 -1 .286 -1 .390 -1 .081 -0 .125  -0 -0  .409 .505 .050 .272  cisOxide  Acetone  -1. 174 0 .045 -1.. 174 .567 0 .040 .587 0 . 130 -0. 762 — 0 . 185 .699 — • .717 -0 . 113 — -1. 767 -0 . 150 — .420 -0 .072 .634 -0 .320 - - 1 . 194 — -0 .473 -0:646: — .014 -0:.'232r: .712 -0 :i98.. -1. 854 -1. 921 .642 -0 :355: .578 -0 :032.: - 1 . 168 — -1. 114 -0 .372 .444 -0 .008 " -1. 000 .264 -0. 568 .523 0 ;o3o: -0. 959 — -0. 722 0 .134  —  -1 -0 -0 -0  —  -0 0 -0 0  Pnopanal  -0 -0 -0  -0 .380 —  -0 .276 -0 .366  ^0 -1 -0 -0 -0 -0  :970 . 123 .588 .796 .782 .479  -0 0 -0 -0  .448 .000 .222 . 148  -  0 . 89±0 .10 0.96±0.13  10~ - mole -5 5 ( B u t e n e ) i < 10 5  taAcetButane aldehyde  —  -0.48±0.34 0.31+0.25  (Butene), >  (*%)  5  l  -  r  1  -0.44_Q119 0.63±0.07 0.47±0.07 .0/67+0708 -0.07±0.13  log(A%)  - (Product) (2-Butene)  x  ±  1  Q  0  Acetone & t-Oxide 51 50 49 48 47 46 45 44 43 42 41 40 39 38 37 36 35 34 33  -5.622 -5.747 -5C896 -5.553 -4.914 -4.956 -5/326 -5.330 -4.349 -4.408 34.604 -4.833 -5.136 -5.257 -5.502 -5.636 -6.000 -5.706 -5.870  Order  -0.094 -0.276 0 .201 0 .060 -0.400 —  -0.400 -0.830 -0.909 -0 .843 —  -0 .517 -0.518 -0.324 ^•0.686 -0 .340 — —  -0.060  trans-Oxide -0.399 • —  0 .025 -0.145 — —  -1.793  -1.177 —  -0.842 -0.860 -0.851 — . —  0 .369 —  Isobutanal 0 .034 -0 . 100 01.68 0 .220 -0 .134 0 . 188 0 .053  -  -0 .118  0 .004 -0 .041 -0 .136 —  -0 .096 0 .053 0 . 146  —  0.16+0.15  0.90+0.08  Butanone 0.041 -0.104 -0.025 0 .095 -0.074 0.006 -0.077 -0.408 -0.553 —  -0 .036 -0.203 -0.261 -0 .018 -0.383 -0.046  IXoc  X„„  «°  38  —  -1..064 -1..076 -0..866 -1..544 -1..269 ^1 .199 —  -1,.433 -1,.686 -1,.468 -1 .750 -1,.534 -1..000  -  —  —  —  -0.022 0.0 80  -1 .232  0 .80+0 .09  -0.252 -0.658 —  -0.461 -1.304 -1.101 -0.796  -  -1.026 -1.418 -1.330 -1.523 -1.236 -0.627  —  0 .000 -0.854  —  0.60±Q.11 • 0.28+0  149 APPENDIX IV. Trans-2-Butene Reactions w i t h O-Atoms Nomenclature  1. 2. 3." 4. 5. 6. 7. 8. 910.  Run No. N f l o w r a t e i n M-mole/mih O^atom f l o w r a t e = No f l o w r a t e i n jxmole/min 2-Butene f l o w r a t e i n U-mole/min T o t a l p r e s s u r e i n mm Hg' L i n e a r v e l o c i t y i n cm/sec ( 0 ) i i n gm-atom/1 (2-Butene)± i n mole/1 ((0) /(2-Butene) ) x 100 A%( ( ) ) methane, ethane, ethylene (2-Butene) 2  i  ±  P r o d u c t  x  100  o  f  ±  11... 12. 13.  14 . 15.  16.  17.. 18. 19. 20. 21. 22. 23.  24. 25. 26. 27. 28. 29.  A% A % A % A% A% A %  A % A % A % A % A% A % A% A% A% A % A% A % A %  of Propane of Isobutane of 2-Butene of X 4 2 of acetaldehyde of X 6 o of Propanal of cis-2,3-butene oxide of acetone of trans-2,3-butene oxide of I s o b u t a n a l of Butanone of B i a c e t y l of X 3 3 of X 3 8 of T o t a l peroxides of c i s - t r a n s i s o m e r i s a t i o n of carbon d i o x i d e of oxygenated products  150 Item 1 2 3. 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 29  Run 92 93 94 96 95 157 220 288 0 .7 0 .5 1 .0 2 .5 40 32 35 46 0 .23 0 .23 0 .27 0 .27 80 .4 112 129 171 0 .064 0 .033 0 .057 0 . 11 1 .7 0 .94 ' 2 .8 1.. 1 -5 .96 0 .38 . 0 .041 0,.136 0 .0603 0 .045 , 0.. 126 0 .201 , 0 .038 0 .015 , 0 .038 1.. 1  1 .6 1 .3 2 .2 1..2 -5 .86 0 .44 , 0 .023 0 ., 171 0 .085 , 0 .044 0 ., 164 0 . 184 0 .025 . 0 .019 . 0 .027 . 1..2  2 .9 1 .0 2. 1 1,.8 -6 . 10 0 .394 , 0 .068 , 0 ., 170 0 .0854 0 .059 0 .048 , 0 . 117 0 .216 , 0 .019 . 0 .025 . 0 .0496 . 1.. 1  5 .4 0 .88 1 .7 1..4 -5,.59 0 .35 0 .098 , 0 .263 , 0 .079 . 0 . 16 0 . 190 0 .304 . 0 .024 , 0 .043 , 0 .086 . 1..5  97 98: 99 100 396 439 581 722 4 .7 7 .. 1 6. 1 12. 1 40 44 41 48 0 .30 0 .36 . 0 .42 0 .49 202 188 205 220 0 . 17 0 ,. 28 0 . 22 0 ,40 1..5 1..7 1,. 5 1. 6 12 .0 16.,0 15,.0 25. 0 1..4 1.,7 0..93 1. 5 2 .4 2. 8 1..6 2. 6 1..3 1. 6 1..4 1. 9 -6,.9 -8. 65 -5,.90 -8. 66 0 .0029 , 0 ,0091 . 0 .40 0 .039 0 .44 . 0 .40 0 . 12 0 .24 0 .078 . 0 .15 0 .333 , 0 .530 0 .370 , o: 710 0..084 0 .12 0 . 10 o. 14 0 . 188 0 .13 0 ., 14 o. 28 0 .095 0 ,071 , 0 .210 , 0 .339 0 .230 . o. 320 0 .319 , 0 .456 0 .366 , 0. 456 0 .021 , 0 .016 0 .015 . o. 037 0 .047 . 0 .052 0 .066 . o. 093 0 .081 , 0 .093 0 .087 . o. 12 1,.7 2. 3 2..0 2. 6 1  CO  O  rH  CD CO |> T}< Ol ^ CO <H O O © O  00  00OCNO©O©CN©©r-liHC0 rH © Tt* CN |  m oo 00 ©o  m © © t> 011>- © r> CO CO O O r-l o rH r-l O O O CO CM  O O O O O  CO 00 CO O 00 Tt* ©inoir>oocMrHoort*Tt* l O H H O H C O O O H N I D  O rH CN © CO CM i-H CM  l f l O t » O O O O H 0 0 r i H H ( C O O H N N Tt ' C I CD I rH t> CM  O O O O O O  I  O O O O O O O O O O O  1  0 01  t> r—I r—I Ol CO C0t>rH00OC0r-H00CM<N01Tt* COO!©COCM|>CMrHCMCOrHrHCOOrHCO  00 COIN  tooNBoooHmnrfntooooHoooooooo o oo Tt* in  I-H  m  rH CM  CO  CO  m t>  r>  I-H I  m rH CDt> 00f>OCN0000rH COaiCMC101©©r>0©CMTF01 moco*#o©ooocMCMocoinorHrH  rH Ol © 00  m Omt>OTf*OO00CMC0CMrHoOOOOOOOO O O o o Ol CM CO o © rH CO rH m 1 rH  t>  o l>  oi co © m © oo t> m co t> oi Tt* co o oo co Tt* rH Ol Ol o > n t ^ o o o ^ o © r H i M c o t o o o  © © CO  Tt* co m m o in O rH O C N C M r H O O O O O O O O m i O O CM TF 00 CM rH CO rH  © ©  00  CM  rH in  o  o Tl* CM  rH  CO  ©  o  o oo o  CO (N  CM rt* © O CO  Tfimincocor>©i>-Tt*cMCMoico 0 ) Q O O O O O ^ r H ( D H N o N ^ O O H CO  Ol CO rH  m  o  O m © rH 00 Tl* r> CO © o o © o i m o o c i © t> CM O Ol 01©00t>O^OmrHrHfN CO o o o  oo in  M i O N N O N O H N H N H O O O O O O O O O o co CM m t> Tt* i r H CM CM  CN O TP (N o CO rH rH Tf< o m CM rH o rH  COO o  Tt* Tf  in CM  CO Tfi CO O Ol © CM Ol rHTtfC0Omm©©C0C0rH©r> mC0©T]*OC0rHTt*rHrHOCMC0OOO  r - H 0 1 C O © 0 0 0 0 ' - ! t > r H C M r H r > © 0 0 0 0 0 0 0 0 0 0 0 O © rH CO TF CO I rH 00 CM  CM  iHCMcort*in©t*ooo^orHc<ico^in©r^oooior-icMco'*in©ai Hrlr-IHHHHHHHNNNCMNNMN  Item  1. 2.  3 . 4 . 5.  6.' — 8. 9. 10 . 11. 12. 13 . 14. 15. 16 . 17 . 18. 19 . 20 . 21. 22. 23 . 24. 25. 26. 29.  Run  119 69 0 .9 40 0 . 15 99 .7 0 .067 3 .0 2 .3 1 .3 3 .7 2 .6 =•9..06 0..091 0 .23 0..081 0 ,0064 , 0,.0306 0 .,092 0..056 0..295 0.,0024 0..021 0 .,0925 0 ..082 1..3  120 877 5 .0 45 0 . 54 234 0 . 16 1 .4 11 2.1 2 .7 1..4 - 8 . .85 0 ..0054 0 ,.836 0 ..028 0 ..535 0.. 195 0.. 13 0., 12 0.,084 0 .,375 0 .,021 0 . 132 0 .,244 0 .,044 2.,8  121 960 15 .2 40 0 . 56 246 0 .45 1 .2 38 1..2 1 .8 1..3 - 5 .61 0 ,.11 0 .22  0- ..345 0 .. 102 0 ..066  0., 114 0 .222 , 0 . 013 0..045 0 ..052 0 .. 122 1..5  122 2660 47 59 1.10 342 1.0 1.3 80 1.8 2.2 2.1 -9.20 0 .14 0 .31  - .850 0 0.24 0.38 0 .10 0.253 0 .523 0.015 0.12 0 .082 "0.284 2.6  123 1740 11 .2 10 .5 0 .85 297 0 .28 2 .6 11 1 .2 2..0 2 .3 -9 .00 0..630 0.. 12 0..857 0 ..18 0..23 0.,22 0..628 0.,029 0..20 0 ..346 0..0236 3..5  124 1620 10 66 0 .83 272 0 .27 1 .8 15 1 .0 2 .8 3 .1 - 8 , .99 0..23 0,.20 0.,26 0..453 0 . 12 0.. 14 0..071 0 .24 , -  0 ..086 0 ..14 0..011 1.,7  125 126 1760 1610 14 27 125 136 0 .88 0 .88 293 284 0 .35 0 .70 3.1 3 .5 11 20 1..3 0 .70 , 1..9 0 ,.85 1 .6 1..2 - 7 . .36 - 4 , .30 0 .062 . 0 ,46 0 ., 16 0..066 0..675 0 ..405 0 . 12 0 .. 12 0.. 17 0., 16 0. 093 0. 053 0..097 0., 172 0.,387 0 ., 281 0.,0095 0.,0013 0. 139 0 .,069 0 ,244 . 0 .,065 0 .,344 2. 5 : 2.,2  Item 1. 2. 3. 4. 5. 6. 7 . 8. 9. 10 . 11. 12. 13. 14. 15. 16. 17 . 18. 19. 20. 21. 22. 23 . 24. 25. 26. 28. 29.  Run 127 128 1640 1610 15 .6 20 .5 46 27 0 .84 0 .84 276 265 0 .42 0 .56 1 .2 0 .74 34 76 2. 1 3 .0 3 .4 4 .0 2 .8 2 .5 -13 .4 -12 .35 0 . 18 0 . 19 0 .61 0 .69 0 .020 0 .072 1 . 11 1 .01 0 .24 0 .29 0 .29 0 .28 0 .079 0 .27 • • 0 . 19 0 .57 0 .643 0 .0077 0 . 18 0 . 19 0 .287 0 .22 0 .043 4. 1  4 .0  129 1770 33 .4 22 0 .82 302 0 .81 0 .54 152 4 .5 4,.8 4..0 -19 .0 0..31 0..804 0 .026 1..65 0..41 0..42 0 .. 15 0..38 0..960 0..042 0. 27 0..31 5..8  130 1840 29 15 0 .85 302 0 .71 0 .37 193 6 .4 7 .7 6 .2 -28 .6 0..46 1,.19 0 .14 2 .54 0..52 0.62 0 .21 . 0 .46 1..28 0..050 0..307 0.,423 8 .2  132 1900 29 46 0..89 302 0..71 1,.1 63  133 1920 20 98 0..89 312 0 .47 2..3 20  134 1920 37 60 0.92 298 0..91 1..5 62  135 1920 34 24 0 .89 302 0. 83 0 .59 142  1.54  1.99  -  1.38  0..630  m  m  CM  <N  O  C J rH  CO  N O H 0 0 H d O H r > ( C co Tt< -r< co co rH ^ CM  CO  m  _>  CO  t>  t> o  Ttf  m  r H r H C l O O O r H O r H C O C O C J CM CO f> rH ^ CM rH  t>  rfi  CO CO  CO CD rH  ^  m  O r H C M O O C O O r H l O ^ ^ c o CM TJ< m in r-H r H CM  oo  m m  TJ< CM  to  CM  CJCMCOCOOCOOrHCOCO CO O rH CO CO CO rH 00 CM  CD  co -<tf  o CM ^  m CM  O O C O m C J O C D O ' - H ^ C M CO O CO O rH rH CD CM  m CM m co 1> ^ O CO O (O CO O CO 00 r-i rjt rH  i>  o CM rH o co m co O H rl rl  ^  rH  oo CM  m o co  o  c o o m c j o c o o o m c D CO CO CO rH C J  rH CO  OJ rH CO  rHCMCOTPmCDOCOCJOO CM  APPENDIX V Dependence on (O)j f o r the "Reaction Between 0-atoms and trans-2-butene  Run  lggCOi  l o g (A%) transButene  122 121 120 119 118 116 115 106 105 104 103 102 101 100 99 98 97 96 94 93 92 Order  -5 .996 -6 .343 -6 .802 -7 . 178 -6 .780 -6 .165 -6 .211 -6 .054 -6 .214 -6 .179 -6 .235 -6 .399 -6 .409 -6 .394 -6 .662 -6 .556 -6 .767 -6 .968 -7 .244 -7 .485 -7 . 192 (n)  0.964 0 .749 0.947 0.958 0.600 0.792 0.874 1,212 1.058 0.948 0.943 0.956 0.870 0 .938 0 .771 0 .937 0 .840 0 .748 0 .786 0 .768 0.776 0 .15+0 ,06  CH ,C H & C H 4  2  2  6  4  0.252 0.090 0.316 0.106 -0.090 0.076 0.190 0.518 0.405 0.299 0 .283 0 .270 0. 176 0.176 -0.032 0.219 0.148 -0.054: 0.007 0.116 -0:028"  Propane 0.344 0.248 0.431 0.600 0.136 0.190 0.294 0.688 0.480 0.405 0.415 0.447 0.358 0.410 0.201 0.449 0.378 0 .228 0.316 0 .332 0.442  i«-But ane 0 .328 0.125 0.133 0.410 0.057 0.123 0.188 0.550 0.356 0.225 0.258 0.255 0.190 0.267 0.140 0 .216 0.110 0.146 0.243 0.085 0.058  0.03+0.07. 0.22+0.07  0.12+0.06  X . 4  2  -0.848 -0.975 -2.265 — •  Acetaldehyde  Propanal  -0 .506 -0 .668 -0 .078  -0 .070 -0 .462 -0 .272  - —  • —  —  —  —  -0.962 -1.009 -0.663 -1.041 -1.001 -1.097 -1.236 -1.367  -0 .615 -0 .346 -0 .110 -0 .208 -0 .354 -0 .336 -0 .348 -0 .487 -0 .394 -0 .358 -0 .406 -0 .398 -0 .456 -0 .404 -0 .354 -0 .418  •—  -2.042 -2.539  --  -  2 23+0:22  J  -0 .248 -0 . 196 . 0 .072 -0 .047 -0 .218 -0 .254 -0 .200 -0 .342 -0 . 148 -0 .432 -0 .276 -0 .478 -0 . 580 -0 .770 -0 .767 -0 .866  ..0.54+0.06 -0.01+0.,08 - •  log ( A % ) Run  log(0)i  c i s - O x i d e Acetone  122 121 120 119 118 116 115 106 105 104 103 102 101 100 99 98 97 96 94 93 92  -5 .996 -6 .343 -6 .802 -7 . 178 -6 .780 -6 . 165 -6 .211 -6 .054 -6 .214 -6 . 179 -6 .235 -6 .399 -6 .409 -6 .394 -6 .662 -6 .556 -6 .767 -6 .968 -7 .244 -7 .485 -7 . 192  -0 .616 -0 .992 -0 .709  Order  (n)  —  -1 .328 -0 .833 -0 .786 -0 .692 -0 .585 -0 .738 -0 .742 -0 .778 -0 .821 -0 .857 -0 .996 -0 .936 -1 .077 -1 .100 -1 .069 -1 .072 -1 .220  -0 .422 —  -0 .896 -1 .514 —  -0 .730 -0 .777 -0 .485 -0 .572 •—  -0 .712 -0 .706 -0 .790 —  -0 .842 -0 .889  transOxide -0 .983 —  -0 .939 -1 .038 —  -1 . 134 -1 .268 -0 .960 -1 . 114 • — —  -1 .143 -1 .200 —  -1 . 149 -1 .020  —  —  —  • -  -1 .231 -1 .362 -1 .350  -1 .322 — —  0.36+0.07 0.07+0.09 ~ 0.65+0.06  Isobutanal Butanone -0 .596 -0 .942 -1 .075  —  -0 .726 -0 .772 -0 .733 -0,. 523 -0 .484 -0 .583 -0 .612 -0 .635 -0 .495 -0 .638 -0 .470 -0,.678 -0 .721 -0 .930 -0 .786 -0 .898 .19+0.08  -0 .281 -0 .654 -0 .426 -0 .530 -—  -0 .490 -0 .406 -0 .206 -0 .250 -0 .348 -0 .422 -0 .370 -0 .470 -0 .340 -0 .436 -0 .341 -0 .496 -0 .517 -0 .666 -0 .735 -0 .697  Biacetyl  X35  x  -1 .810 -1 .896 -1 .684  -0.918 -1.348 -0.880 -1.686 -2.119 -1.096 -0.943 -0.701 -0.830 -1.022 -1.113 -1.032 -1.208 -1.032 -1.180 -1.283 -1.326 -1.366 -1.609 -1.728 -1.836  -1 .096 -1 .288 -0 .613 -1 .034 -1 .796 -0 .830 -0 .812 -0 .464 -0 .719 -1 .031 -1 .032 -0 .886 -1 . 102 -0 .920 -1 .060 -1 .032 -1 .092 -1 .064 -1 .304 -1 .572 -1 .404  -2 .022 -1 .788 -1 .920 -1 .678 -1 .545 -1 .770 -1 .620 -1 .700 -1 .796 -1 .638 -1 .824 -1 .798 -1 .674 -1 .614 -1 .722 -1 .611 -1 .422  38  0.65+0. 12 0.26+0.05 ~ -rO. 11+0.07 ~ 0.40+0.13  cn  Peroxide from t r a n s Run  log (0)i  Log A  116 119 120 121 122 127  -6.165 -7.178 -6.802 -6.343 -5.996 -6.379  -0.61 -1.09 -1.36 -0.91 -0.55 -1.37  n =  1  C O 2 from t r a n s 137 138 139 140 141 142  -7.709 -6.699 -6.360 -6.202 -6.108 -6.037  n = 0.50+0.12  0.117 0.352 0.514 0.657 0.550 0.801  APPENDIX VI Dependence on (trans-2-butene)i Reaction Between 0-atoms and trans-2-butene  log Run 130 129 128 127 126 125 124 123  log  (t-Butene)^ t-Butene -6..436 -6 .272 -6,. 130 -5 .910 -5,.452 -5..503 -5 .754 -5 .584  Order (n)  1.457 1.278 1.126 1.092 0 .634 0 .868 0.954 0 .954 0.35+0.09  CH4,C H $ C2H4 2  6  Propane  (A %)  i»-Butane  Acetaldehyde  cis-oxide  0 .806 0 .652 0 .474 0 .330 -0 .158 0 . 114 0 .007 0 .094  0.884 0.678 0.598 0.532 -0.070 0.272 0.450 0.292  0.13+0.11  0.40+0.22 0.41+0.05 0.36+OJ ~~ 0.47+0.11 0.36+0.15  0 .790 0 . 597 0 .391 0 .450^ •0 .086 0 .210 0 .494 0 .354  0.076 -0.095 -0.159 -0.21S -0.796 -0:336 -0.706 -0.200  Propanal 0 .405 0 .218 0 .004 0 .045 -0 .392 -0 . 170 -0 .344 -0 .067  -0.287 -0.387 -0.534 -0.612 -0.917 -0.917 -0.924 -0.752  Run  log ( t - B u t e n e ) i Acetone -6 -6 -6 -5 -5 -5 -5 -5  130 129 128 127 126 125 124 123  436 272 130 910 452 503 754 584  Order (n)  -0.208 -0 .378 -0.561 -0.542 -0.798 -0.762 -0.866 -0.638 0.47+0.11  Run 132 133 134 135 136 Order  CO -5.950 -5.635 -5.829 -6.233 -6.674  0.141 -0.201 0.187 0.299 1.205  (n) -0.24+0.22  transoxide -0 676 -0 833 —  -1 102 -1 273 -1 034 —  -  0.53+0.14  Isobutanal Butanone -0.340 -0.422 -0.576 -0.733 -0.764 -1.013 -1.147 -0.658 0.45+0.20  0 -0 -0 -0 -0 -0 -0 -0  109 018 192 244 551 412 612 202  0.45+0.16  Biacetyl  X35  %3a  -1.298 -1.377  -0 .512 -0 575 -0 730 -0 .756 -1 163 -0 857 -1 065 -0 706  -0.373 -0.503 -0.651 -0.542 -1.184 -0.613 -0.870 -0.461  :—  -2.114 -2.883 -2.022 •-  -1.538  -0.03+0.50 0.58+0.23 ~ 0.53+0.16  APPENDIX VII R e s u l t s of P r e s s u r e - t i m e Studies f o r the O x i d a t i o n of 2-butenes By Molecular Oxygen at 289°C Run, p _Butene ^ p mm P mm T°C 2  0 o  10 2  6  1  2  27.6 53.7 289 t min P mm 0 5 .0 7 .0 13 .0 17 .0 19 .0 19 .3 19 .5 19 .8 20 .3 21 .6 24 .7 29 .0 33 .6 36 .7  53 .4 53 .5 53 .5 53 . 5 53 .5 53 .9 58 .6 55 . 1 56 . 1 57 .2 57 .4 57 .7 58 . 1 58 .5 58 .6  11* • 27.4 53.3 289 5  9  13 1  6  14  0  1  2  24.8 40.7 289  1  5  P  t  P  t  0 5.0 10 .0 15. 0 20. 0 23. 0 24. 8 25. 1 25. 2 25. 5 25. 7 25. 8 26. 0 26. 4  53. 3 53. 3 53 .3 53 .3 53 .1 53. 0 53 .4 58. 9 57 .2 58. 6 54. 5 56. 5 57 .0 51. 2  0 35..0 37 . .0 40.,0 42.,6 42..8 43. 0 43.A 43..5 43.,7 44'.,-oc 44. 2 42.,7 45. 6 46. 0 50. 0  40 .7 40 .7 40 .9 40 .9 46,.0 46 .0 42 .0 42 .9 43 .5 44,.0 44,.9 45 .5 45,.6 45,.9 46 .0 46,.4  0 30 40 48.,0 60. 0 66. 1 65. 3 65. 7 66. 2 66. 4 67 .0 67 .6 68. 0 70. 0 71. 5 73. 0  P  16  9  28.4 40.9 288.5  t  *Insufficient  15  5  1  35.0 50.9 288.5 t  40..9 0 40 ,9 , 9.,0 40 . ,7 19. 0 40.,6 22. 3 40,,6 30 , .0 46,.5 39. 2 42.,4 39. 4 42.,7 39. 45 44,,4 39. 9 44.,9 40. 0 46. 3 40. 3 47 ,4 . 40 ,5 . 47 , .7 '40. 8 48.,4 41. 0 48.,7 41. 5 48. 8 41. 7 41. 9 42. 2 42. 4 45. 2 50. 7 55. 0 e v a c u a t i o n p r i o r t o run (see page 83 )  2  • 5  41.4 53.9 288.5  P  t  P  51 .0 51 . 1 51 .1 51 .0 51 .0 51 .4 52 .0 59 .3 53 .1 56 .3 54,.9 55,.6 57 .3 57 .6 59 .1 59 .4 59,.9 60,.3 60,.5 61,.4 62,,1 62,.6  0 17 .3 30. 0 46. 0 47 .0 47 .5 48. 0 48. 4 49. 2 53. 0  53. 9 54. 1 54. 0 54. 1 61. 7 62. 4 62. 9 63. 1 63. 6 64. 8  (35 O  Run p Butene p mm P mm T °C  17 • 37.8 50.9 289 1  2  n  2  3  18  1  8  24*  0  2  42.3 50.3 28975  tram  Pmm  0 5.8 10.5 30 .0 39.1 39.4 39.5 39.7 40.0 40 .2 40.3 40 .4 40 .6 41.1 41.4 41.7 42.1 44.0  50 .9 0 51 .0 2 .0 51 .1 13 .7 51 .0 42 .7 51 .3 63 .0 51 .6 89 .3 58 .3 120 53 .0 124 .6 53 .3 125 .0 53 .7 125 .2 63 .4 125 .4 55 .4 125 .6 55 .6 125 .75 56 .5 126 .0 57 .4 126 .7 58 . 1 127 . 1 58 .9 127..5 60 .0 128 .0 128 .3 130 .0 135 .0  vt  P 50 .3 50 .4 50 .6 50 :6 50 .4 50 .3 50 . 1 50 .4 50 .6 50 .7 51 .0 51 .4 51 .7 52 . 1 53 . 1 53 .7 54 . 1 54 .4 54 .5 55 . 1 56 .0  5  4  25 2  0  26.2 51.6 289 :;t 0 5,.8 35..0 40..0 40.. 1 40,.4 40..9 41 .2 43 .0 46 .8  P 51..6 51,.9 51,.9 56,,9 53,. 1 54,.4 55.. 1 55..3 55 .6 55..9  •  4  26 1  0  31.0 51.4 289  •i 0 5,.0 12..0 15,.5 19 .0 26 .7 37 .8 40 .0 49 .0 57 .4  P 51 .4 51..6 51..6 51..6 51..6 51..6 58.,3 58..5 59..1 59,.5  •  5  27 2  9  41.4 51.9 289.5  :t 0 38 65..0 74..0 80 82 87 .3 . 96  P 51..9 52. 3 52..1 52. 1 58..0 58.,5 60.,4 61.,9  -  5  :;t 0 2 .0 7 .0 , 12 .0 15 .0 18 .0 21 .0 25 .0 28 .0 28 .6 28 .9 35 .0 48 .8  21.8 51.3 289 P 51 .3 51 .4 51 .6 51,.9 51 .9 52 .0 52 .0 52 .0 53 . 1 53 .2 53 .4 53 .9 54 .3  (Si  Run P2-Butene o P T p  2  mm mm mm  28 36.4 15.7  29 40.5 11.5  52.1 289.5  52.0 289.5  t min P mm 0 4 .0 11 .6 19 .0 40 .0 47 .3 50 .0 51 .0 53 .0 60 .0 65 .0 71 .5 76 .0  tmin  P mm  52 . 1 0 52,, 1 6 .0 52 . 1 20 .0 52 .3 45,.0 52 . 1 81,.0 52,.1 90 .0 52,.0 205 52.. 1 52.,4 52..4 52 .6 52,.7 52 .6  52 .0 52.,0 52..0 51 .9 51,.3 51..3 51..7  163  APPENDIX V I I I R e s u l t s of K i n e t i c S t u d i e s f o r the O x i d a t i o n o f 2-butenes By Molecular Oxygen at 289°C 1. P r e l i m i n a r y R e s u l t s Run mm Hg Pbutene-2 • p 0.56 Ptotal 108 T°€ 283°C 0  5 2  0  48 158 620  Note:  -4 1.53x10 -5 4.06x10 305 9.5 xlO -3 1078 1405 1430 p  2 0.58 0 . 52 1.10 283°C  3 0.54 mm 0.62 1.16 284.5°C  2.66x10-4 1.13xlO 3.44x10-4 4.58xl0~ 4  1394 1410  4.4x10 -4 4.40x10 -4  pp = p r e s s u r e of propanal p^ = pressure of i s o b u t a n a l P _B  = pressure of n-butanal  P  = p r e s s u r e of butanone  t  B o  5.4 15.5 25.7  -,:5  = p r e s s u r e of acetaldehyde  n  4 21.2 16.4 37 .6 284°C  = r e a c t i o n time i n min.  i n mm Hg M  It  II  8.15x10 6.4 xlO  164  Run  8  Pbutene mm Hg O P Jftotal T°C p  5 27 4 42  10 .4 9.83  10.4 8.55  9.55 8.70  9.69  20 .2  18.95  18.25  290.5  290 °C  288°C  2  .120 209 252 489 1468 Ri  289°C  -4 5.96x10 1.48x10 -3  1.50SX10"  3.96x10-3 1.19xl0~  7.6xl0"  2  6  3  11.5 24.4 48.4 77 124 195  mm/min  3.72x10 -3 3.71x10 -3 7 .27x10-3 2.09x10 -2 4.17x10 -2 1.52xl0~ : 4  12.7 1.1x10 -3 32.5 ( 8 . 6 9 x l 0 ) 51.8 2.78xl0-3  3  162 281  2.18x10 1.092 1.40x10 -4  -2 284 316  2.45x10 -2  5.6x10 -5  2. Run Ptrans-2-Butene P0 s Ptotal T°C 1,1111  H  2  t  Pa  9.2 12.0 20 .3 24.7 36.3  2 6 4 3 3  T o t a l Pressure Constant  30-31 20 .1 31. 5-31.8 51.6-51.9  32-33 24.6-25.1 26.6-27.0  289°C  289.5°C.  51.6-51.7  _£  -2 02x10 23x10 -2 20x10 -2 09x10 -1 1  3 .4 xlO -3 1 96x10 -2 1 13x10 -2 9 2 xlO -2 2 .84  -4 1.04x10 -3 2 01x10 -2 1. 13x10 -2 2 33x10  7.9 12.0 22.0 25.0  1.34xl0~ 4.29xl0 1.23x10 -1 1.70x10 -1 2  - 2  1.50x10 -3 5.36x10-3 8.34x10-3 1.02xl02  1.33xl0" 4.22xl0 1.40x10 -2 1.16xl03  - 3  2  log Ri  -2 67  -3 52  -3 .82  -2.54  -3.31  -3.60  log 0  -1 55  -1 28  -1.09  -1.34  •1.68  -1.27  34 10.0 mm 41.7  35 6.0 45.3  Ptotal  51.7  51.3  T°C  289°C  289.5°C  Run Ptrans-Butene P0  2  £i 21.0 40.9 62.9  1.02xl0 2 2.12x10-2 3.92xl0-  2  3 61x10 -4 4 10x10 -4 4 66x10 -4  1.38x10 -3 3.14 10 -3 4.66 10 -3  18.0 36.2 59.0  1.19 10 -3 2.19 10-3 1.38-10-2  log Ri  -3.12  ; 4.47  -4.15  -4.01  log 0  -1.85  .1 -2.58  -1.75  -1.84  _  1.0 10 1.09 10 9.0 10 " -5.00  3.37xl0" 1.02x10-3 1.65 10 4  4 5  -4.82 -1.62  05  3. Run Ptrans Butene Pfj Ptotal 2  T°c  36-37 38.4 13.6 52.0  1 7 2 3  5.70x10 -2 1.38x10 -1 3.15x10 -1 1.57 mm  290°C  02 85 .85 67  02  39 16.2 26.6 42.8 289.5 Pi  IE 21 30 50 74  Constant p  10~ 10 10~ 10"  2  - 2 2 1  8.84 1.44 4.11 5.38  : Pi  Pa 10 -3 10 -2 10 -2 10 -2  21.0 41.2 60.0 80 .1  1.72x10 -2 5.12xl0~ 1.40 l O 0.513 2  - 1  9 11x10 -4 1 09x10 -3 3. 07x10 -3 7 , 60x10 -2  2.78x10"^ 8.01x10-3 1.69 1 0 4.72 10 -2 - 2  log Ri  -2.48  •3.30  -3.31  -3.04  -4.09  -3.74  log 0  -1.575  -1.55  -1.64  -1.614  -2.398  -1.697  o>  40 10.25 27 .0 37 .25 289°C  Run Ptrans-2-Butene PO2  Ptotal  41 6.13 26.8 32.93 289°C Pp  20.2 40 .0 64.6 90 .2  2.98x10 -3 8.69x10 -3 1.53x10 -2 2.52xl0 - 2  7.16xl0" 1.95x10-4 2.59x10 3.15xl04  4  -3 1.34x10 9.76x10 -4 -3 1.57x10 2.55xl0~ 3  40.0 83.2 124.0 160.0  6.49x10 -4 2.13x10 -3 -3 7.90x10 1.235xl0-  log R i  -3.87  -4.81  -4.26  -4.54  log 0  -2.02  -2.381  -2.078  -1.89  Pn-B 40.0 64.6 90.2 log R i  1.41x10 3.27 10 -3 4.60 10 -3 -4.81  Pn-B  PBo 8.69 1 0 ~ 2.14 10~3 2.67 10 -3 4  -5.08  83.2 124 160  -3 1. 55x10 1 975 10" 2 47 10 -3 -4.02  Pi  1.30xl0~ 8.87x10-^ 7.40xl0~ 1.235::10"4 4  5  2  2.48 4.22 7.90 8.27  -4.78  -4.72  -2.300 PBo 6.65 10"4 7.40 10-4 1.24 1 0 - 3  -4.48  10~ 10~ 10" 10"  4 4 4 4  42 40.0 27 .4 57 .4  Run Ptrans-Butene P0 Ptotal T°C 2  44 61.9 27 .1 89.0  43 40.0 28.9 58.9 290.0  290. 5°C  290 .5 Pa  5.3 10 .3 15.0 21.5  2.74 I O 8.43xl0 2.25 l O 2.24  - 2 - 2 - 1  8.56 10 -3 1.74 10" 3.62 I O 2.28 2  - 2  1.51 10 -3 1.13 10"~ 1.53 I O 8.55xl0 - 2  5.0 11.0 16.0  1.075x10":; 3.55 1 0 , 6.65 1 0 _ 1  2. 40x10 -2 -2 7 .65 10 3.02 10"  1  4.20xl0" 1.87 1 0 " 2.82 I O "  3  _ 1  log R i  -2.10  -2.78  -3.02  -1.52  -2.16  -2.80  log  • 1.026  -1.190  -0.900  -1.143  -1.00  -0.448  0  Pn-B 21.5 15.0 log R i  0.518 1.72 l O -2.12  PBo - 1  0.180 -2 7.15x10  -2.47  Pn-B 5.0 11.0 16.0  PBo  1.175 10 -2 4.70 I O 8.50 I O - 2 - 2  -2.41  3.78 IO , 1.74 10"^ 3.48 10~ -3  Z  r-2.84  2 2  Run Pcis-Bu P0 Ptotal 2  T°c  47 25.05 26.8 51.8  50 24.8 27 .6 52.4  289.5  291°C  Pt rans 8.0 22.0 49.0 0 log  PJ  2.51x10 6.49 1 0 ~ 1.14 2.92x10 -2  2  Ri  c i s  log Ritrans  9.0 20.0 30 .0  2.13 1 0 ~ 8.05 10"? 1.98 10 -1 2  -2.61 -2.54  170  4.  Run  R e a c t i o n Order f o r Acetaldehydes Ri  log p  B u  log Ri  log ( p ) r log a  3  PBu>  (  32-33  1.395  -2.46  29  1.210  -3.04  40  1.011  -3.87  41  0.788  -4.54  42-43  1.602  -2.10  44  1.792  -1.52  36-37  1.134  -7.23  35  1.657  -6.34  34  1.620  -6.12  32-33  1.428  -6.73  30-31  1.502  -6.59  Order  3.01+0.17  1.95+0.32  APPENDIX IX Determination of the Gaiem3ration~oi A c t i v a t i o n Energy of the O x i d a t i o n of 2-butenes by Molecular Oxygen, 289-357°C 1. T°C 10 / o Run PBu (Bu>i o (0 )i total 3  T  p  2  2  p  log R i log  k  Note:  a  K  trans-2-Butene  289.5  302.7  315.7  1.778 32-33 24.6-25.1 7 .05xl0~ 26.6-27.0  1.734 53 25.3 7 .05xl0" 27 .6  7 .60xl0~ 51.6:^:51.7  7.68xl0~ 53.0  1.699 55 19.8 5.36x10 -4 29.8 8.06x10 -4  -7.09  -6.576 9.110  4  4  8.604 Pg  u  a  345.2  346.3  356 .3  1.648 58 20.4 5.39 26.6  1.618 60 14.8 3.85 15.7  1.617 62 17 .1 4.45 15.7  1.589 63 18.4 4.66 18.7  7 .04 47 .0  4.07 30.5  4.08 32.8  4.74 37 .1  -6.541  -6.096  -6.501  -6.414  -5.855  9.455  10 .012  10.521  10.420  10 .786  49.6  = i n i t i a l p r e s s u r e of 2-butene i n mm Hg.  (Bu)initial :  4  4  333.7  c o n c e n t r a t i o n of 2-butene i n moles 1 -1  = o v e r a l l r a t e constant f o r the p r o d u c t i o n of acetaldehyde a d u r i n g the i n d u c t i o n p e r i o d , i n 1 m o l e m i n - 4  - 1  2. T°C 10 / o Rune Bu (Bu^ M T  k  p  PQ  2  (0 ) M Ptotal 2  i  log Ri l o g ka  291.0 1.773 50 ' 7.05xl0~ 27.6 7.84xl0 2  4  8  2 4  - 4  5  2  4  -7.16 8.508  303.5 1.732 54 • 7.13 28.2 7.84  5  5  3  6  9  316 1 1.699 56 ' 5.40 19.9 5.40 1  3  9  9  9  8  1  3  9  cis-2-Butene  315.3 1.700 57 • 5.29 20.2 5.49 5  9  7  333.7 1.648 59 1  9  345.1 357.7 1.618 1.582 61 64 16.4 14 . 1 4.26 3.56 14.3 15.4 3.70 3.91  5  5.15 20.4 5.38 3  9  9  3  0  7  2  9  5  4  309.0 1.718 65 20 . 5 5.66 20.8 5.74 1  3  -6.855  -6.948  - 7.094  -6.356  -6.872  -6.389  -7.006  8.797  9.392  9.256  110.046  10.102  10.735  9.216  

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