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UBC Theses and Dissertations

A. The anodic oxidation of Benzene. B. The effect of certain chemicals on the hydrolytic activity of… Archibald, Reginald MacGregor 1932

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UlB.C.  A. THE AHODIC OXIDATION OF BENZENE. B.  THE EFFECT OF CERTAIN CHEMICALS OU THE HYDROLYTIC ACTIVITY OF RICINUS AID PORK PANCREAS LIPASE.  BY  Reginald MacGregor A r c h i b a l d  A Thesis submitted f o r the Degree of MASTER O F ARTS  i n the Department of CHEMISTRY  The U n i r e r s t i y of B r i t i s h Columbia  LIBRARY *  A.  THE  ANODIC OXIDATION OF HENZEHE.  CONTENTS. I  #  Introduction  «1  Purpose  .. .1  Summation of factors to "be considered  1  Means of moderating the intensity of oxidation 1. concentration, s o l u b i l i t y and solvent.....6 2. decrease overvoltage (a) AC on DC  ...8  ( D ) intermittent....10 3. choice of anode material.................11 4. c a t a l y s t s , etc.  ...14  5. cathode cooperation, diaphragm, e t c .  14  6. size of anode, current density, etc  15  7. power f a c t o r  16  8. other factors  17  Suggestions  18  Pros, and Cone, of Electrochemical manufacture..19 I I . Previous Work Mechanism o f Electro-oxidation I I I . Experimental.  21 21 ...24  Method  24  Apparatus} c e l l and e l e c t r i c a l hook-up  25  Phenol t e s t s .  26  R e c t i f i e d Current  .28  Types of current used.  ,29  CONTENTS cont'd.  Page IT.  Results Decomposition p o t e n t i a l s . By-products Phenol y i e l d s  .30 30 ,31 33  V.  D i s c u s s i o n of R e s u l t w .  35  VI.  Summary  36  V I I . Bibliography  38  Figures and Graphs.  Figure 1 to face page 24. Figure 2 to face page 2 5 . Figure 3 to face page 2 5 . Figure 4 to face page 29.  Graph I to face page 30. Graph II to face Graph I. Graph I I I to face fraph I I .  THE ANODIC OXIDATION OF BENZENE.  I.  Introduction*  Purposes The investigation was carried on with a view to f i n d i n g ( l ) whether or not there i s truth i n the predictions of several organic electrochemists, that on e l e c t r o l y t i c oxidation ofbenzene the product f i r s t formed i s phenol, and i f t h i s be true, then to discover (2) what factors influence the y i e l d of t h i s product, thereby determining by what means the y i e l d can be increased. Summation of factors to be considered: Of the two reactions encountered i n organic e l e c t r o chemistry, v i z . oxidation and reduction,^ the former i s the least developed.  The greater d i f f i c u l t y experienced  in c o n t r o l l i n g the factors which influence the reactions of organic electro-oxidation have l e d , i n the past, to i n t r i c a t e courses of reactions, r e s u l t i n g i n low y i e l d s and disappointment.  Hence electro-organic chemistry has not  been regarded as a very f r u i t f u l f i e l d f o r commercial manufacture.  E s p e c i a l l y i s t h i s true i n the case of  aromatic compounds.  For, the f a t t y compounds, being, as a  rule, the more readily oxidized, break up i n stages t i l l 1.  Trans. Am. Electrochem.  S o c , 40, 109, (1921).  2. f i n a l l y , they are converted into carbon dioxide and water, whereas the aromatic compounds form phenolic condensation products of a resinous nature.  Though d i f f i c u l t i e s have been  many, and the r e s u l t s , as a rule, disappointing, nevertheless, experiments i n t h i s f i e l d have been numerous and some, expecially those involving the use of c a t a l y s t s , have l e d to i n t e r e s t i n g r e s u l t s .  I t has long been known  that anodic oxygen oxidizes aromatic compounds by the introduction of hydroxy! groups.  If the reaction at the  anode could be s u f f i c i e n t l y controlled, benzene could be converted into the r e l a t i v e l y more valuable commercial product, phenol. F i c h t e r and other elctro-organic chemists believe that phenol i s the f i r s t Brockraan  1  oxidation product of benzene.  refers to a work of F i c h t e r and Uhl  2  i n which  these l a s t , using benzene with a twice normal solution of sulphuric acid at 60° i n an atmosphere of carbon dioxide, obtained at a platinum anode, a small quantity of phenol. In a l a t e r work F i c h t e r  states that he was unable to  prove that phenol i s the f i r s t oxidation product of benzene. A search of the available l i t e r a t u r e has brought to l i g h t no other cases where phenol has been obtained e l c t r o l y t i c a l l y 1. "Electro-organic Chemistry 2. Helv. ChiBi. Acta, 3, 22,  H  (1926).  (1920).  3. Trans. Am. Electrochem. S o c , 4j5 112, f  (1924).  3. from M n z « n e  itself.  However, Hoppe-Seyler  1  o b t a i n e d from benzene, w a t e r ,  and p a l l a d i u m h y d r i d e sponge i n t h e p r e s e n c e o f a i r , s u f f i c i e n t phenol t o detect q u a l i t a t i v e l y .  Leeds ^  observed t h a t i n t i m e , a v e r y d i l u t e s o l u t i o n o f hydrogen p e r o x i d e c o n v e r t e d benzene d i r e c t l y t o p h e n o l .  Nencki  3  f ound t h a t oxygen o f t h e a i r i n t h e p r e s e n c e o f sodium h y d r o x i d e c o n v e r t e d benzene t o p h e n o l . Heiberg,  C r o s s , Bevan and  by u s i n g f e r r o u s s u l p h a t e w i t h two m o l e c u l a r  w e i g h t s of hydrogen p e r o x i d e t o one o f benzene, o x i d i z e d 10 g. o f benzene o b t a i n i n g 1.5 g. o f p h e n o l . t h i s i n d i c a t e s that phenol i s the f i r s t ,  Undoubtedly  ( o r a t l e a s t one  of t h e f i r s t ) , p r o d u c t s o f o x i d a t i o n o f benzene.  The f a c t  t h a t o x i d a t i o n w i t h hydrogen p e r o x i d e y i e l d s , v e r y o f t e n the same p r o d u c t s as does a n o d i c oxygen, t o g e t h e r w i t h t h e f a c t t h a t hydrogen p e r o x i d e o x i d i z e s benzene t o p h e n o l , would l e a d one t o expect t o f i n d p h e n o l as one of t h e p r o d u c t s o f e l e c t r o - o x i d a t i o n o f benzene. There a r e s e v e r a l reasons f o r t h e f a c t t h a t under o r d i n a r y c o n d i t i o n s p h e n o l has n o t been d e t e c t e d as a product of e l e c t r o l y s i s .  F i r s t , the process of e l e c t r o l y t i c  1. B e r . 12, 1552. 2. B e r , 14, 975. 3. B e r . 14, 1144. 4. B e r . d D e u t . Chem. Ges. 3 3 , 2017.  4. oxidation i s so hard to control that the reaction proceeds past the phenol stage, and higher oxidation products are formed.  Second, "benzene i s highly resistant to oxidation  being oxidized appreciably only by ozone, hydrogen peroxide, mono persulphuric a c i d , and by the most e f f e c t i v e of a l l oxidizing agents, anodic oxygen. hand i s r e l a t i v e l y more easy to oxidize.  Phenol, on the other The more the  benzene nucleus i s saturated with oxygen, the more r e a d i l y decomposition into oxalic a c i d , carbon dioxide,etc., takes place.  Hence phenol, as soon as i t i s formed, being a  better depolarizer than benzene, i s almost completely oxidized to higher products before more benzene i s converted into phenol.  Or, i n other words, with respect to c e r t a i n  compounds, there i s an equilibrium set up i n which the concentration of phenol i s very low.  Third, benzene i n most  e l e c t r o l y t e s * i s much less soluble that phenol.  Hence a  s u f f i c i e n t concentration of reactant cannot be obtained to act as a good depolarizer. i s slow and incomplete.  As a r e s u l t , the anode reaction  The product phenol, however, being  quite soluble i n the e l e c t r o l y t e , takes the place of the benzene as a depolarizer and i s oxidized to a higher state. Fourth, as a r e s u l t of the i n s o l u b i l i t y of benzene, i t i s impossible to regulate closely the voltage to the oxidation p o t e n t i a l , i . e . , to the voltage $ust s u f f i c i e n t to oxidize "benzene to i t s f i r s t stage of oxidation.  F a i l u r e to  overcome these d i f f i c u l t i e s has led experimenters to obtain  5. from benzene the following products, p-p' diphenol quinone <- hydroquinone  1  o-p* diphenol ————-quinol  with diaphragm  and catechol  *  butyric  maleic acid and p-benzoquinone  formaldehyde  racemic acid and formic and  oxalic  t a r t a r i c acids and  or withdiaphragm  carbon dioxide and C  4 4°5 H  a  n  d  C  succinic  fumaric  7 6 4 ffl»P«93 H  G  Also n-valeric and malonic acids, o-hydroxyphenol,ethers, diphenyltetrahydroxydiphenol, dihydroxydiphenol ester, phenolic resins, e t c . There appear to be two possible ways of stopping the oxidation as soon as i t reaches the phenol stage.  First  by removing the phenol from the e l e c t r o l y t e as soon as i t i s formed and second, by moderating the i n t e n s i t y of the e l e c t r o l y t i c oxidation. been accomplished.  So f a r , the f i r s t step has not  D i s t i l l a t i o n of phenol even from a  solution of a stronger acid does not take place (unless the l a t t e r has a higher b o i l i n g p o i n t ) , since the concentration of the phenol i s so very small.  P r e c i p i t a t i o n of the  phenol, or some compound of phenol from the e l e c t r o l y t e would s h i f t the reaction equilibrium i n the desired d i r e c t i o n and would prevent further oxidation, since the phenol could no longer act as a depolarizer.  But a l l known means  of p r e c i p i t a t i o n are either too expensive, or else interfere  6. w i t h t h e d e s i r e d r e a c t i o n or e l e c t r o l y s i s .  So f a r , no  means of washing out the p h e n o l f r o m the e l e c t r o l y t e by the use o f a n o t h e r l i q u i d immiscable w i t h the a n o l y t e , w h i c h i s s u i t a b l e t o t h i s p a r t i c u l a r p r o c e s s have been The  devised.  second e x p e d i e n t , v i z . t h a t of m o d e r a t i n g the  i n t e n s i t y of e l e c t r o l y t i c o x i d a t i o n seems most u s e f u l .  T&ere  a r e many ways of d o i n g t h i s , and the most of t h e s e depend on the r e g u l a t i o n of the v o l t a g e used,--hence a l s o of e f f e c t i v e pressure The  and c o n c e n t r a t i o n  f i r s t and most o b v i o u s way  concentration  the  of a n o d i c oxygen. i s to increase  the  of t h e benzene i n t;he e l e c t r o l y t e so  that  benzene r a t h e r t h a n p h e n o l w i l l a c t as the d e p o l a r i z e r . In the p a s t , t h e e l e c t r o l y s i s of benzene has been c a r r i e d on i n d i l u t e s u l p h u r i c a c i d s o l u t i o n s in w h i c h benzene i s insoluble*  I t i s probable.' t h a t the p r i m a r y p r o d u c t s are  the same w i t h a l k a l i n e s o l u t i o n s as w i t h s u l p h u r i c a c i d s o l u t i o n s except t h a t new  complications  s e t i n owing t o  t h e i n s t a b i l i t y of quinone i n a l k a l i n e s o l u t i o n s . Unfortunately  most e l e c t r i c a l l y c o n d u c t i v e  solvents  aqueous e l e c t r o l y t e s do not d i s s o l v e benzene, and t o F i c h t e r , even t h e f i n e e m u l s i o n s produced by  and according  vigourous  s t i r r i n g a r e f a r f r o m b e i n g as e f f e c t i v e as t r u e s o l u t i o n s . However BrockmanI s a y s t h a t a s o l u b l e c a t a l y s t i s s u f f i c i e n t t o make up f o r a p o o r s o l v e n t .  Sodium a c e t a t e  1. " E l e c t r o - o r g a n i c C h e m i s t r y , " p 15. 2. J . Chem. I n d . Japan, 24,  567  (1921),  (1926).  and  7. alcohol  have "been used t o i n c r e a s e  1  r e a c t a n t , hut and  the s o l u b i l i t y of  the f i r s t substance does so o n l y  slightly  the l a t t e r becomes i t s e l f , the d e p o l a r i z e r .  The  t h e n , i s t o f i n d a n o t h e r more s u i t a b l e s o l v e n t .  problem  I t i s to  be e x p e c t e d t h a t the p r o d u c t w i l l v a r y w i t h the s o l v e n t The  the  used.  i d e a l s o l v e n t f o r t h i s r e a c t i o n would (1) d i s s o l v e l a r g e q u a n t i t i e s of benzene, (2) have a low s p e c i f i c  resistance,  (3) be not  too  (4) be  i n which phenol i s i n s o l u b l e , ( since i t s  one  volatile,  removal f r o m the s o l u t i o n p r e v e n t s f u r t h e r (5) be a t t a c k e d  o n l y s l i g h t l y by the e l e c t r i c  (6) be m i s c i b l e  i n a l l proportions  (7)  i f p o s s i b l e , be  oxidation). current.  w i t h water,  and  inexpensive.  P y r i d i n e , e s p e c i a l l y w i t h a r o m a t i c compounds, has  a tendancy  t o f o r m t a r r y s u b s t a n c e s which r e s u l t i n l o s s of o  material.  G l a c i a l a c e t i c a c i d t o w h i c h has been added  a s m a l l amount of w a t e r f u l f i l l s . a l l the above r e q u i r e m e n t s except (2) and current  (4).  appreciably,  w a t e r w i t h a few  T h i s w i l l not conduct the  electric  (not n e a r l y as w e l l as w i l l a l i t e r of  c c . of a c e t i c a c i d } . But  i f i n s t e a d of w a t e r ,  a few c c . of c o n c e n t r a t e d sodium h y d r o x i d e s o l u t i o n are added, the s o l u t i o n becomes a good c o n d u c t o r of and  the benzene i s s t i l l s o l u b l e .  1. B e r . 2. H. D.  m_p Law,  1942,  The  acetic acid is  (1894).  J . Chem. Soc.,  89, 1437,  electricity  (1906).  8. only s l i g h t l y attacked.  Bourgoin  1  found that of a l l the  acids t r i e d , acetic was the hardest to e l e c t r o l y z e , - - e s p e c i a l l y •when concentrated.  The g l a c i a l acid d i l u t e d with an  equal volume of water gave 29.7% of oxygen and 2.3% of carbon dioxide.  Hopfgartner  2  using anhydrous sodium  acetate i n g l a c i a l acetic acid with platinum electrodes got 49.28% carton dioxide, 1.17% ethylene, .16% of oxygen, 21.06% of ethane and 27.85% of hydrogen  ("by volume).  Warming and the presence of a l k a l i decreased the y i e l d of ethane.  Other products are carbon dioxide, methyl acetate,  methyl carbonate, methyl formate and formic a c i d . The second means of moderating the intensity of oxidation i s by decreasing the overvoltage of oxygen at the anode and the oxidation p o t e n t i a l of the electrodes. The o x i d i z i n g power of an anode depends, i n part, on the p o t e n t i a l difference between the anode and the solution. The decrease i n oxygen overvoltage can be accomplished, to some extent, by the superimposition of a l t e r n a t i n g on d i r e c t current,  Goodwin and Knobel  have studied the  effect of a l t e r n a t i n g current on overvoltage, at platinum, copper, and lead electrodes.  By the use of a variable frequency  generator which gave a sinusoidal current wave, they experimented over the range of 2 to 100 cycles per, sec.  1. Ann. Chim et P&ys. (4) 14, 157, (1868). 2. HOnatsch 32, 523-61. Chem Abst. 5_, 3438. (1911). 3. Trans. Am Electrochem, Soc. 3*7, 617, (1920).  They found that the decrease in overvoltage was of the ration a l t e r n a t i n g current d i r e c t current  and was  a function  independent of  the material of the electrodes and of the current density. They state that the effect i s n e g l i g i b l e when the r a t i o i s l e s s than .7 and reaches a maximum when the r a t i o i s 3.2. There i s , however, some difference of opinion as to whether or not there i s a minumum value which must be exceeded before an appreciable e f f e c t i s produced.  The  effect  increased s l i g h t l y , (50mv. over the range studied), as the frequency  was diminished.  The power f a c t o r has a small  influence , the change from 0 lead to .5 lag giving a difference of 30 mv.  The decrease of i r r e v e r s i b i l i t y of  the d i r e c t current electrode process i s said by Cooper to produce remarkable effects at frequencies below 10 cycles per sec.  1  By the superimposition of a l t e r n a t i n g an direct  current, the retardation phenomenon and p a s s i v i t y in anodic metal s o l u t i o n can be eliminated and the l i m i t i n g current density at which metal solution ceases can be r a i s e d ,  2  Though most of the work has been concerned with the effect of overvoltage of hydrogen at the cathode, Grube and 3 Dulk observed that a high r a t i o of a l t e r n a t i n g current d i r e c t current lowered considerably the overvoltage of oxygen at platinum anodes.  Oxygen was  obtained at a p o t e n t i a l less p o s i t i v e  1. Trans. Farad, S o c ,  18, 102,  (1922).  2. Marsh, P r o c Roy. S o c , A. 97. 124, 3. Z e i t . Elektrocheat., 24_, 237,  (1918).  (1920).  10. than the r e v e r s i b l e value.  Marie  1  f o u n d t h a t when o x i d i z i n g  a l c o h o l t h e v o l t a g e a t a p l a t i n u m anode i n an a c i d medium r o s e f r o m .7 t o 1.1. He c o u l d c a r r y on t h e o x i d a t i o n a t the l o w e r v o l t a g e by u s i n g an i n t e r m i t t e n t c u r r e n t . simply prevented p o l a r i z a t i o n .  Reitlinger,  2  This  by u s i n g  a l t e r n a t i n g c u r r e n t superimposed on d i r e c t c u r r e n t , was a b l e t o reduce t h e p o l a r i z a t i o n t o such an e x t e n t t h a t an a l c o h o l gave t h e c o r r e s p o n d i n g  aldehyde r a t h e r than the  a c i d w h i c h r e s u l t e d when d i r e c t c u r r e n t o n l y * was u s e d . That i s , by t h e use o f a l t e r n a t i n g on d i r e c t c u r r e n t , t h e e f f e c t i v e v o l t a g e o r o x i d a t i o n p o t e n t i a l i s l o w e r e d so that products  c a n be o b t a i n e d w h i c h a r e i n t e r m e d i a t e between  t h e r e a c t a n t s and t h e p r o d u c t s alone.  obtained w i t h d i r e c t  current  These phenomena a l l p o i n t t o t h e p o s s i b i l i t y o f  r e g u l a t i n g t h e i n t e n s i t y o f o x i d a t i o n by t h e s u p e r i m p o s i t i o n of a l t e r n a t i n g on d i r e c t c u r r e n t , t h i s expedient  had t h e d i s a d v a n t a g e  b u t w i t h p l a t i n u m anodes of causing  excessive  c o r r o s i o n of the e l e c t r o d e s . An e x p e d i e n t  c l o s e l y a s s o c i a t e d w i t h t h i s i s t h e use  of an i n t e r m i t t e n t , (though n o t a l t e r n a t i n g ) , c u r r e n t . In t h e f o l l o w i n g e x p e r i m e n t s such a c u r r e n t has been o b t a i n e d by t h e use o f t a n t a l u m  electrodes i n acid solution.  The a l t e r n a t i n g c u r r e n t o f t h e d e s i r e d v o l t a g e was a p p l i e d . 1. C h e l O b s t . , 3 2 , 4345^. Compt Rend, 2. Z e i t . f Phys. Chem., 44, 8 1 , (1903). 3. See a l s o T r a n s . Am.Electrochem. S o c . , 4 1 , 151, ( 1 9 2 2 ) .  11.  The  tantalum e l e c t r o d e almost completely r e c t i f i e d  this  current. The  t h i r d means of m o d e r a t i n g the  i n t e n s i t y of  the  e l e c t r o l y t i o o x i d a t i o n , r e l a t e d i n some ways t o the i s i n the c h o i c e  of p r o p e r anode m a t e r i a l .  The  second,  choice  of c o n d u c t o r s f o r an anode i s r a t h e r l i m i t e d , - - m u c h more l i m i t e d t h a n i n t h e c a s e of the c a t h o d e , - - s i n c e many m e t a l s s u i t a b l e f o r cathodes are attacked  a t the anode.  choice f o r a l k a l i n e s o l u t i o n s i s l i m i t e d to palladium,  i r i d i u m c a r b o n , i r o n , and  absence of ammonium s a l t s ) . use  c a r b o n i n t h e f o r m of  The  platinum,  n i c k e l , ( i n the  In a c i d s o l u t i o n s we  Acheson g r a p h i t e  can  ( i n solutions  c o n t a i n i n g C I " ) , p l a t i n u m ( i n absence of h a l i d e s ) , and  lead or lead peroxide ( i n sulphuric a c i d solutions  s p e c i f i c g r a v i t y up t o 1.6, concentrations  or s o l u t i o n s w i t h anjr  of p h o s p h o r i c a c i d , n e u t r a l  p h o s p h a t e s , c a r b o n a t e s and  chromates).  sulphates,  Carbon has  d i s a d v a n t a g e of d i s i n t e g r a t i n g m e c h a n i c a l l y and has  t o o low a c o n d u c t i v i t y .  Oxidation  i s slowly attacked  I r o n and  1  and  deposited  Next t o these a r e  n i c k e l ( e s p e c i a l l y spongy  n i c k e l ) anodes have the l o w e s t o v e r v o l t a g e 1. F i c h t e r , T r a n s . Am.  magnetite  i s s a i d t o p r o c e e d most  v i o l e n t l y a t smooth p l a t i n u m anodes. l e a d d i o x i d e anodes.  the  Copper i s a s u i t a b l e anode  f o r moderate o x i d a t i o n s , but on the c a t h o d e .  with  E l e c t r o c h e m . Soc.,  as shown by 4j5, 110,  the  (1924).  12. following table. Electrode STetal  P. D.  Electrode Metal  An Pt (smooth)  1.75 1.67 1.53 i* ?  Pt (platinized) go Ni (smooth) Ni (smooth)  4  P. D. 1.47 1.36 1.35 1.28  The oxygen-hydrogen c e l l voltage i s 1.22 As mentioned above, F i c h t e r considers oxidation nore v i o l e n t at smooth platinum electrodes than at lead dioxide anodes.  However, i t i s to be noted that i n c e r t a i n cases  t h i s i s true only as regards the nucleus, the reverse being true of the side chain.  For, Elbs  1  found that at  smooth platinum anodes p-nitrotoluene oxidized to p-nitrobenzyl a l c o h o l and p-nitrocresol, while lead dioxide anodes y i e l d p-nitroben?oic a c i d .  This probably has some-  thing to do with the difference in the tendency to form molecular oxygen at the two anodes.  At the anode where  molecular oxygen i s most e a s i l y formed, the oxidation of the side chain would be expected to be most energetic, while the oxygen at the other anode would attack c h i e f l y the nuclear hydrogens.  For F i c h t e r and Stocker  that anodic, (supposedly  atomic), oxygen attacks the  nucleus before the side chain. the case with halogens.  This i s also known to be  It i s well to remember, when  1. Z. f . Elektrochem., 2, 522, ( 1 8 9 6 ) . 2. Ber. 4 7 , 2003, ( 1 9 1 4 ) .  have found  13. choosing anodes f o r use with a l t e r n a t i n g current, that the greatest e f f e c t of the superimposed current i s noticed when the metal electrode i s covered with i t s insoluble salt.  It i s to be expected that the products which can  be obtained at d i f f e r e n t kinds of anodes w i l l vary somewhat due to the difference i n overvoltage  of various  electrodes  and also due to the c a t a l y t i c e f f e c t s of c e r t a i n materials.  Which of these two  anode  influences i s the most  important i s a subject of debate.  The r e l a t i v e effect of  each f a c t o r v a r i e s , probably, f o r each new  set of conditions.  Iron and n i c k e l anodes i n a l k a l i n e solutions are good f o r oxidations only at high current d e n s i t i e s . l It i s to be remembered too, that electrodes of platinum in p a r t i c u l a r , do not always behave as they are expected to. The nature of the surface, whether smooth or spongy,— whether or not the electrodes have been anodically or c a t h o d i c a l l y p o l a r i z e d , and the past h i s t o r y of the electrodes arw- f a c t o r s which have decided £he e l e c t r o l y t i c processes.  2  influence on the course of  Prepolarization seems to  Convert the electrode into a very l a b i l e and active condition which i s not, as yet, understood.  One would expect the  mildest oxidation from an electrode which had never been used as a cathode. 1. D.I.P. 297019,(1900), and 141343 (1902). 2. Brockman's "Electro-organic Chemistry," p37.  (1926).  14. The  f o u r t h e x p e d i e n t i s the use  of s a l t s of  multivalent  m e t a l s s u c h as vanadium, c e r i u m , manganese and,  (with  diaphragm o n l y ) , chromium, w h i c h a c t as c a r r i e r s o r 1  catalysts.  These speed up a b s o r p t i o n  d e p o l a r i z e r and  increase  expedient, according  of oxygen by  the  the e l e c t r i c a l e f f i c i e n c y .  Ihis  to Brockman, i s most u s e f u l where the  d e p o l a r i z e r i s i n s o l u b l e i n the e l e c t r o l y t e . The  oxidation  i s thought t o p r o c e e d q u i t e e a s i l y w i t h o u t the c a t a l y s t s where t h e d e p o l a r i z e r i s s o l u b l e . A f i f t h means of c o n t r o l l i n g the o x i d a t i o n i s the c o o p e r a t i o n o m i s s i o n of a diaphragm.  i n t e n s i t y of  of the c a t h o d e , - - i . e . ,  the the  Some o x i d a t i o n p r o d u c t s from  anode a r e reduced p a r t i a l l y , a t the c a t h o d e . I f  initial  reduction  the  of the d e p o l a r i z e r a t the c a t h o d e , and  of a diaphragm a r e u n d e s i r a b l e , can be a v o i d e d by the use  excessive  of a cathode of s m a l l  by h a v i n g a l a r g e c a t h o d e c u r r e n t most of the c a t h o d i c form.  Or,  use reduction  area,i.e.  d e n s i t y which causes  hydrogen t o eacape i n the m o l e c u l a r  i n s t e a d , one may  c h l o r i d e or c a l c i u m  cathodic  the  add  s m a l l amounts of  calcium  s a l t s of r e s i n a c i d s , o r , ( i n the case  of n e u t r a l or s l i g h t l y a c i d s o l u t i o n s ) , s o l u b l e chrornate.  2  T h i s l a s t forms a t h i n s k i n of chromic o x i d e over the cathode s u r f a c e a c t i n g as a diaphragm and p r e v e n t i n g reduction  of the anode p r o d u c t s .  1. T r a n s . Am.  E l e k t r o e h e m . , Soc.,  2. Z. E l e k t r o e h e m . , 9, 583,  cathodic  An a l k a l i n e s o l u t i o n 4jD, 123,  (1903).  (1921).  15. makes r e d u c t i o n more d i f f i c u l t and hence checks the e f f e c t of the c a t h o d e .  The  a d v i s a b i l i t y of the use  diaphragm seems t o be a p o i n t of d e b a t e .  1  of a  The  mechanical  d i f f i c u l t i e s of c l o g g i n g , h a r d e n i n g , d e c o m p o s i t i o n , and  incress&d  r e s i s t a n c e w h i c h a t f i r s t made the diaphragm  seem an u n m i t i g a t e d  n u i s a n c e , have been overcome, even i n  t h e p r e s e n c e of t a r r y b y p r o d u c t s , by the use filtros." for  use  heating  of the " E l e c t r o -  T h i s t y p e of diaphragm, however, i s not s u i t a b l e  i n strong a l k a l i n e solutions.  I t i s the  opinion  of T h a c h t e r t h a t f a i l u r e t o use a diaphragm has been the cause of much t r o u b l e . A s i x t h means of c h e c k i n g  o x i d a t i o n i s t o keep the  c u r r e n t d e n s i t y below one ampere p e r . s q . the use  of l a r g e anodes.  Electrodes  dm.,--i.e. by  i n the f o r m of  concentric  c y l i n d e r s p e r m i t the most even d i s t r i b u t i o n of c u r r e n t p r e v e n t most c o m p l e t e l y  excessive  o x i d a t i o n w h i c h would  r e s u l t f r o m the p i l i n g up of c u r r e n t on c e r t a i n p a r t s the e l e c t r o d e s .  The  e f f i c i e n c y when u s i n g l a r g e c u r r e n t s .  The  a n o d i c oxygen.  The  the  l a r g e anode  p e r m i t s a g r e a t e r q u a n t i t y of d e p o l a r i z e r t o be  of d e p o l a r i z e r , ( u p  of  l a r g e r the anode, the l e s s oxygen  escapes as m o l e c u l a r oxygen, and hence the g r e a t e r  w i t h the evolved  and  g r e a t e r the  i n contact concentration  to a c e r t a i n p o i n t ) , the greater i s  the  c u r r e n t d e n s i t y w h i c h can be used w i t h o u t e v o l u t i o n of  gas.  1. D i s c u s s i o n T r a n s . Am.  (1924).  Electrochem. S o c ,  45, p 104,  16. The weaker t h e d e p o l a r i z e r , ( n o t o n l y a s r e g a r d s "but a l s o a s r e g a r d s i t s r e d u c i n g nust be t h e c u r r e n t d e n s i t y .  concentration,  p r o p e r t i e s ) , the less  Current concentration, i . e .  ampers p e r . l i t r e o f s o l u t i o n , a l s o p l a y s an i m p o r t a n t r6\le. A s e v e n t h means o f c h a n g i n g o r r e g u l a t i n g t h e p r o d u c t s of a l t e r n a t i n g c u r r e n t e l e c t r o l y s i s has been s u g g e s t e d .  1  This i s t h e s e l e c t i o n o f t h e most s u i t a b l e power f a c t o r . The f a c t t h a t t h e appearance o f c e r t a i n l i n e s i n an a r c s p e c t r u m depended upon t h e r e l a t i o n o f c a p a c i t y and i n d u c t i o n i n t h e c i r c u i t , I . e . , whether o r n o t t h e E.M.F. was i n s t e p w i t h t h e c u r r e n t , l e d P a t t e n  to the conclusion  t h a t t h e p e r c e n t a g e of a l t e r n a t i n g c u r r e n t a v a i l a b l e f o r d o i n g work may i n f l u e n c e t h e p r o d u c t s formed. O t h e r f a c t o r s w h i c h i n f l u e n c e t h e n a t u r e and c o u r s e of e l e c t r o l y s i s  i n g e n e r a l , and w h i c h s h o u l d be  i n t h i s research a r e s t i r r i n g , temperature* e t c . and  others consider  s t i r r i n g an a b s o l u t e  successful p r o s e c u t i o n  considered Brockman  necessity f o r the  o f an e l e c t r o l y s i s .  In cases  where a n e m u l s i o n o f t h e d e p o l a r i z e r i s m a i n t a i n e d , t h i s f a c t o r i s a u t o m a t i c a l l y a t t e n d e d t o . B u t even where t h e d e p o l a r i z e r i s i n t r u e s o l u t i o n t h e r a t e of e l e c t r o l y t i c r e a c t i o n i s u s u a l l y g r e a t e r t h a n t h e r a t e of d i f f u s i o n . Hence, u n l e s s f r e s h q u a n t i t i e s o f t h e d e p o l a r i z e r a r e mechanically c i r c u l a t e d t o t h e anode s u r f a c e , e i t h e r 1. T r a n s . Am. E l e c t rochem. S o c , 2 9 , 313, ( 1 9 1 6 ) .  17. excessive o x i d a t i o n w i t h l o s s of m a t e r i a l o r undesired e v o l u t i o n o f oxygen w i t h decrease w i l l take p l a c e .  i n current efficiency  Temperature must be r e g u l a t e d i f t o o  v i g o r o u s o x i d a t i o n i s t o be prevented.  F o r each  o x i d a t i o n r e a c t i o n t h e r e i s an optimum c o n c e n t r a t i o n of d e p o l a r i z e r f o r each v a l u e o f c u r r e n t d e n s i t y and concentration. A n o t h e r p o i n t t o be c o n s i d e r e d i s t h a t e x c e s s i v e and u n d e s i r e d d e c o m p o s i t i o n  of the organic  starting  m a t e r i a l may be due t o t h e f o r m a t i o n of i n t e r m e d i a t e peroxides.  1  I f f a c t o r s which discourage or prevent the  f o r m a t i o n o f peroxides, c a n be d i s c o v e r e d , i t may be p o s s i b l e t o exclude peroxides from the s o l u t i o n to c o n t r o l the extent of o x i d a t i o n .  thereby  Such f a c t o r s as  t h e s e have y e t t o be d i s c o v e r e d . p  I t h a s been shown by B i r c h e r and H a r k i n s t h a t o v e r v o l t a g e i n c r e a s e s w i t h decrease  and o t h e r s  i n pressure.  It  might be e x p e c t e d , t h e n t h a t by u s i n g l a r g e p r e s s u r e s , t h e o v e r v o l t a g e might be reduced  t o t h e e x t e n t t h a t t h e degree  of o x i d a t i o n c o u l d be c o n t r o l l e d .  However, t h e e f f e c t of  p r e s s u r e i s most e f f e c t i v e a t l o w p r e s s u r e s and Newbery ^ has shown t h a t w i t h oxygen t h e o v e r v o l t a g e i s p r a c t i c a l l y c o n s t a n t over a range o f 1-10.0 atmospheres. 1. T r a n s . Am. S l e c t r o c h e m . S o c , 4 5 , 154 (1924). 2. J . Am. Chem. S o c , 4 5 , 2890 (1923). 3. J . Chem. S o c , 105, 2419, (1914).  18. C e r t a i n groups ( s u c h as the m e t h y l g r o u p ) , when p r e s e n t as a s u h s t i t u e n t i n the benzene n u c l e u s a r e known to  d i r e c t new  groups towards the p a r a (and o r t h o ) p o s i t i o n .  E l e c t r o l y t i c i n t r o d u c t i o n of a s i n g l e h y d r o x y l group c o u l d be e f f e c t e d , p r o b a b l y more e a s i l y i n t o a compound w i t h some such s u b s t i t u e n t t h a n i n t o benzene If this substituent remain.  itself.  c o u l d be removed t h e n , p h e n o l would  T h i s , however, does not appear t o be a v e r y  u s e f u l method. When T o n o l i  1  o x i d i z e d benzene s u l p h o n i c a c i d w i t h  a v e r y h i g h c u r r e n t d e n s i t y a t a p l a t i n u m anode, he p h e n o l and s u l p h u r i c a c i d . experiment  2  obtained  I n F i c h t e r ' s r e p o r t of t h i s  the v a l u e g i v e n f o r the c u r r e n t d e n s i t y used  i s 5 amps, p e r s q . cm. 500 amps p e r s q . dm.  T h i s seems e x c e e d i n g l y h i g h , b e i n g S t o c k e r found t h a t u s i n g l e a d  p e r o x i d e anodes and  .04 amps p e r s q . cm.  y i e l d e d no p h e n o l .  I t appears t h e n t h a t t h e r e i s a  the same compound  p o s s i b i l i t y of o b t a i n i n g p h e n o l e l e c t r o l y t i c a l l y perhaps on a c o m m e r c i a l s c a l e , f r o m benzene.  and  I f the  p r o c e s s were c a r r i e d on near a s u l p h u r i c a c i d p l a n t , the e l e c t r o l y t i c p r o c e s s would be c h e a p e s t . be t r e a t e d w i t h oleum;  Benzene c o u l d  the r e s u l t i n g s o l u t i o n of  benzene s u l p h o n i c a c i d d i l u t e d would be the a n o l y t e from w h i c h p h e n o l and s u l p h u r i c a c i d would be produced. 1. Rend. Soc. Chim. I t a l . F a s c a 2 2. T r a n s . Am.  Electrochem. S o c ,  (1912). 45, p 153.  (1924).  After  19. r e m o v a l of the p h e n o l , t h e r e s u l t i n g s u l p h u r i c a c i d c o u l d he used t o d i l u t e oleum, the m i x t u r e b e i n g pure enough, p r o b a b l y , f o r making f e r t i l i z e r s . E l e c t r o c h e m i c a l p r o d u c t i o n of compounds has advantage  1  t h a t mere o x i d a t i o n i s a c c o m p l i s h e d  the  more  e c o n o m i c a l l y by e l e c t r o l y s i s t h a n by o t h e r c h e m i c a l means and t h a t the absence of i n t e r m e d i a t e o x i d i z i n g r e a c t a n t s a v o i d s expense and c o n t a m i n a t i o n of the p r o d u c t s . n o t e d by U e r n s t ,  2  As  the p r o p e r c o n t r o l of e l e c t r o d e p o t e n t i a l  p e r m i t s a wide range of gas " p r e s s u r e s " a t the e l e c t r o d e surface. nucleus  F u r t h e r , most c h e m i c a l o x i d a t i o n of the  aromatic  i f e f f e c t e d , r e s u l t s i n d i s r u p t i o n of the  ring  w h i l e e l e c t r o c h e m i c a l o x i d a t i o n introduces a hydroxy1 group w i t h o u t b r e a k i n g the  ring.  On the o t h e r hand, d i s a d v a n t a g e s w h i c h i n h e r e i n e l e c t r o c h e m i c a l methods must not be o v e r l o o k e d .  Electrolytic  methods r e q u i r e more room, hence l a r g e r and more e x p e n s i v e p l a n t s , and demand more s k i l l e d a t t e n t i o n and upkeep c o s t t h a n o r d i n a r y c h e m i c a l p l a n t s . need of g r e a t e r amount of t i m e , thought i n the working  greater  F u r t h e r , the  and  expenditure  out of the e l e c t r o l y t i c methods and  the p r e p a r a t i o n of the p r o c e s s f o r l a r g e s c a l e p r o d u c t i o n must be a n t i c i p a t e d .  Most of the d i f f i c u l t i e s  encountered  a t f i r s t , i n v o l v i n g diaphragms, have been overcome, as f a r 1. T r a n s . Am. 2. B r . p 1562 e  Electrochem. S o c , (1897).  3_6, 337  (1919).  20. as a c i d and n e u t r a l s o l u t i o n s a r e c o n c e r n e d , "by the use o f "Electro-Piltros," since  1  d e v i s e d "by T h a c h t e r and i n use  1915.  1. Met. & Chem. Eng.  ( 1 9 1 5 ) . 13, 336-38.  21. II.  P r e v i o u s Work. A s e a r c h of t h e a v a i l a b l e l i t e r a t u r e has r e v e a l e d  no i n d i c a t i o n of any work h a v i n g been done on t h e e l e c t r o l y s i s of benzene i n c o n c e n t r a t e d a c e t i c a c i d Segewetz and Miodon  solution,  used 3 3 % a c e t i c a c i d w i t h 25%  1  s u l p h u r i c a c i d as an e l e c t r o l y t e but even a t t h i s c o n c e n t r a t i o n of a c i d t h e benzene was  not  s o l u b l e t o make an e m u l s i o n u n n e c e s s a r y .  sufficiently Only one  case  has been found where e l e c t r o l y s i s of benzene has y i e l d e d p h e n o l and h e r e n o t h i n g more t h a n a rough q u a n t i t a t i v e estimate i s given.  P r a c t i c a l l y n o t h i n g has been r e p o r t e d  on the use of non-aqueous s o l u t i o n s f o r e l e c t r o l y t i c o x i d a t i o n s . A c e t i c a c i d of the c o n c e n t r a t i o n used i s i n a l i m i t e d  sense,  a non-aqueous e l e c t r o l y t e , f o r w i t h o u t a d d i t i o n of sodium h y d r o x i d e , the c o n d u c t i o n of c u r r e n t i s n e g l i g i b l e . Undoubtedly t h e c u r r e n t i s conducted  by t h e N a a n d +  0H~  i o n s w h i c h would not e x i s t i f t h e r e were not some water p r e s e n t , y e t i t i s by r e a s o n of the l a r g e c o n c e n t r a t i o n of u n d i s s o c i a t e d a c e t i c a c i d t h a t the d e p o l a r i z e r i s h e l d i n true  solution. A Hew  Emphasis as t o The Mechanism o f E l e c t r o - o x i d a t i o n .  I t has been noted  i n the i n t r o d u c t i o n t h a t benzene  can be o x i d i z e d t o p h e n o l by the use of hydrogen p e r o x i d e , e t c . as w e l l as by a n o d i c  oxygen.  In g e n e r a l , anodic  o x i d a t i o n y i e l d s the same, p r o d u c t s as do hydrogen p e r o x i d e , ozone and p e r s u l p h u r i o a c i d . T h i s f a c t has l e d some 1. B u l l . Soc. Chim., (17) 33_, 449 (1923).  22. organic e l e c t r o c h e m i s t s to the c o n c u l s i o n or b e l i e f that such e l e c t r o - o x i d a t i o n i n v o l v e s t h e f o r m a t i o n of a p e r o x i d e of some s o r t a t t h e anode.  1  Hence t h e p o p u l a r i t y  o f s u l p h u r i c a c i d as an e l e c t r o l y t e f o r o x i d a t i o n .  But  O  Fichter  has shown t h a t p r o d u c t s a t t r i b u t e d t o the f o r m a t i o n  of p e r s u l p h u r i c a c i d e t c . a t t h e anode, can be o b t a i n e d a l s o i n p h o s p h o r i c a c i d s o l u t i o n s under c o n d i t i o n s i n w h i c h p e r a c i d s do not form.  Though t h e p e r o x i d e f o r m a t i o n  h y p o t h e s i s has many advantages may  over o t h e r h y p o t h e s i s , and  a p p l y i n some c a s e s , I b e l i e v e the emphasis has been  put i n t h e wrong p l a c e .  I n s t e a d of c o n s i d e r i n g the o x i d a t i o n  t o p r o c e e d as a r e s u l t of t h e f o r m a t i o n of a p e r o x i d e , p l a c i n g the emphasis of t h e s i m i l a r i t y of mechanism on the p e r o x i d e - i t seems t o me,  b e t t e r t o c o n s i d e r the o x i d a t i o n  a r e s u l t of " n a s c e n t " or monatomic oxygen w h i c h forms s u p p o s e d l y , b o t h a t t h e anode and i n the d e c o m p o s i t i o n of the p e r o x i d e s and t h e r e b y p l a c i n g the emphasis of s i m i l a r i t y of mechanism on the format i o n of the  "nascent"  oxygen. I have no r e c o l l e c t i o n of h a v i n g heard of , or of h a v i n g seen i n p r i n t , the emphasis so p l a c ed,-- though be i t g r a n t e d the i d e a t h a t atomic oxygen i s n e c e s s a r y i n both cases i s o l d .  But i t seems t h a t the  resemblance  between t h e c h e m i c a l o x i d a t i o n of p e r o x i d e s and the 1. F i c h t e r , T r a n s . Am. 2. I b i d . 45-, p  111.  E l e c t r o c h e m . S o c . , 45, 0 131  electrical (1924).  23. o x i d a t i o n i s due not t o the presence of p e r o x i d e s i n "both e a s e s , h u t r a t h e r t o monatomic oxygen.  I n s t e a d of e x p l a i n i n g  e l e c t r o l y t i c o x i d a t i o n i n terms of p e r o x i d e s we  can  e x p l a i n t h e mechanism of o x i d a t i o n of p e r o x i d e s i n terms of o x i d a t i o n by s i n g l e m o l e c u l e s t h e case i n a n o d i c o x i d a t i o n .  x  of oxygen as may w e l l be  h i s does away w i t h the  n e c e s s i t y of h u n t i n g f o r p e r o x i d e s i n e l e c t r o l y t e s which seem i n c a p a b l e of p r o d u c i n g them.  24. HI  Experimental,  Method: E l e c t r o d e s of n i c k e l , p l a t i n u m , copper and i r o n were used i n s o l u t i o n s a l k a l i n e w i t h sodium h y d r o x i d e o r a c i d with sulphuric a c i d or acetic a c i d *  I n a l l c a s e s where  c o n c e n t r a t e d a c i d was n o t used, the e m u l s i o n o f benzene was m a i n t a i n e d by use o f a s t i r r e r . for  Qualitative  tests  p h e n o l were made w i t h samples t a k e n f r o m time t o  time, from the e l e c t r o l y t e .  Q u a l i t a t i v e tests f o r phenol  were made w i t h t h e v a r i o u s t e s t s r e c o r d e d  i n the l i t e r a t u r e .  These a r e t o be d e s c r i b e d i n d e t a i l l a t e r .  Quantitative  t e s t s o r determinations of the pehnol content of the r e a c t i o n p r o d u c t s were made o n l y a f t e r s e p a r a t i n g p h e n o l from t h e other o x i d a t i o n products.  I n c a s e s where  c o n c e n t r a t e d a c a t i c a c i d was u s e d , t o 4 0 c c . o f t h e g l a c i a l a c i d were added 5 c c . o f c o n c e n t r a t e d sodium h y d r o x i d e solution.  The d e s i r e d amount o f benzene when added t o t h i s  dissolved readily. gauze, were u s e d .  C y l i n d r i c a l anodes, - - u s u a l l y o f w i r e When d e s i r e d , i r o n o r copper was  e l e c t r o p l a t e d p r e v i o u s l y , onto t h e anode. In  some c a s e s a diaphragm was used.  T h i s was a porous  cup, made o f u n g l a z e d p o r c e l a i n , and j u s t l a r g e enough t o c o n t a i n t h e anode. When l a r g e c u r r e n t s were used, t h e c e l l was  p l a c e d i n c o l d r u n n i n g water t o p r e v e n t  of benzene e t c , by t h e h i g h t e m p e r a t u r e . the c e l l i s found  i n F i g u r e 1.  volatilization  The diagram o f  |jo>-ous cuj? Anode  Benzene  I F i g u r e 1,  25.  The  e l e c t r i c a l hook-up i s shown i n F i g u r e 2 and 3.  In F i g u r e 2, t h e ohmic r e s i s t a n c e ( % ) ,  i n t h e AC c i r c u i t  i s made so l a r g e i n comparison w i t h t h e r e s i s t a n c e o f the o e l l t h a t most o f t h e d i r e c t c u r r e n t f l o w s the c e l l and r e l a t i v e l y of t h e t r a n s f o r m e r .  little  t h r o u g h t h e secondary  coil  O b v i o u s l y a h i g h E.M.F. f r o m t h e  AC s o u r c e must be used t o overcome t h i s resistance.  through  A choke h a v i n g l i t t l e  non-inductive  ohmic r e s i s t a n c e b u t  a l l o w i n g v e r y l i t t l e f l o w o f a l t e r n a t i n g c u r r e n t was p l a c e d i n t h e D.C. c i r c u i t t o keep the AC f l o w i n g through the c e l l r a t h e r t h a n t h r o u g h t h e b a t t e r i e s o r motor generator.  I n F i g u r e 3 t h e DC i s passed  ondary c o i l o f t h e t r a n s f o r m e r . voltmeters are l e f t  The ammeters and  i n c i r c u i t or i n p a r a l l e l  an i n s t a n t a t a t i m e . was  t h r o u g h t h e sec-  f o r only  As t h e AC v o l t a g e a c r o s s t h e c e l l  s m a l l , and as t h e d e v i s i o n s on t h e AC i n s t r u m e n t s  v a r y a s t h e square o f t h e c u r r e n t i n v o l v e d , some d i f f i c u l t y was  experienced  a l t e r n a t i n g PD.  i n o b t a i n i n g an a c c u r a t e measure o f t h e However, t h i s was overcome by measuring  the PD between t h e extreme t e r m i n a l s o f t h e c e l l and o f a non  i n d u c t i v e r e s i s t a n c e i n s e r i e s w i t h t h e c e l l ; and then  across the resistance alone.  The PD a c r o s s A*C  less that  a c r o s s B-C e q u a l s t h e PD a c r o s s t h e e l e c t r o d e s A-B. Q u a l i t a t i v e t e s t s f o r p h e n o l were made f i r s t w i t h bromine w a t e r .  The f r e e a c i d was n e u t r a l i z e d w i t h sodium  h y d r o x i d e and t h e s o l u t i o n made j u s t a c i d w i t h h y d r o c h l o r i c  26. acid.  A d d i t i o n o f bromine w a t e r gave a y e l l o w p r e c i p i t a t e  of t e t r a brom-phenol when p h e n o l was p r e s e n t . J i l l Ion's Reagent,  i n the presence of a n y t h i n g  g r e a t e r t h a n 1 p a r t o f p h e n o l i n 2,000,000. gave a r e d c o l o r a t i o n on s t a n d i n g o r i m m e d i a t e l y a f t e r h e a t i n g . The pres-ence o f a c e t a t e i o n h i n d e r e d t h i s t e s t and made the  red c o l o r a t i o n very t r a n s i e n t .  according to directions H. D. G i b b s .  2  of E l v o v e  1  The reagent was p r e p a r e d as r e p o r t e d by  68g o f mercury d i s s o l v e d  i n 50 c c . o f  c o n c e n t r a t e d n i t r i c a c i d g i v e 40 c c . o f s o l u t i o n t o which 92 c c . o f w a t e r a r e added. N i t r i c  a c i d i s added i f a  p r e c i p i t a t e r e s u l t s and u n t i l s o l u t i o n becomes c l e a r . An e q u a l l y d e l i c a t e t e s t i s r e p o r t e d by Eykman.  3  A few drops o f a l c o h o l i c s o l u t i o n o f e t h y l n i t r i t e added t o p h e n o l s o l u t i o n gave a r e d c o l o r a t i o n a f t e r a d d i n g an e q u a l volume o f s u l p h u r i c  acid.  The t e s t was found t o g i v e  good r e s u l t s when a l c o h o l , sodium n i t r i t e and s u l p h u r i c a c i d were used. There i s a s i m i l a r t e s t w i t h i s o a m y l n i t i r i t e . I s o a m y l c h l o r i d e was used w i t h s a t i s f a c t o r y  results,—the  c h l o r i d e b e i n g c o n v e r t e d t o t h e n i t r i t e as soon as t h e sodium n i t r i t e was added. 1 c c . of p h e n o l s o l u t i o n w i t h 2 c c . o f c o n c e n t r a t e d sulphuric  a c i d h e a t e d w i t h 2 drops o f benzaldehyde  I. B u l l Hyg. L a b . U. S. P. A. 1917 cx 25. 2. J , B i o l . Chem. 7 1 . 450. 3. New Remedies 1882 X I 340*  gave  27. a y e l l o w t o r e d c o l o r a t i o n w h i c h t u r n e d t o b l u e when d i l u t e d and made a l k a l i n e w i t h p o t a s s i u m h y d r o x i d e . A few drops o f s o l u t i o n o f h y p o c h l o r o u s a c i d , UaOCl or hypobromous a c i d , o r KaOBr o r c h l o r i d e o f l i m e , added t o p h e n o l s o l u t i o n w i t h e x c e s s ammonia gave a l i g h t b l u e coloration. L a c t i c a c i d and p y r u v i c a c i d used w i t h s u l p h u r i c a c i d each gave t h e c h a r a c t e r i s t i c c o l o r a t i o n w i t h p h e n o l . D i s t i n c t i o n from  t h e p o l y h y d r i c p h e n o l s was made by  t h e use of s i l v e r n i t r a t e .  The substance t e s t e d d i d  not reduce s i l v e r n i t r a t e as do t h e p o l y h y d r i c p h e n o l s . This f a c t , together w i t h p o s i t i v e r e s u l t s obtained with a l l of  t h e above t e s t s , i n d i c a t e s q u i t e d e f i n i t e l y , t h a t  phenol i s present i n the r e a c t i o n product. Q u a n t i t a t i v e measurement of p h e n o l c o n t e n t was made as f o l l o w s ; - - F i r s t t h e r e a c t i o n p r o d u c t s were made a l k a l i n e w i t h sodium h y d r o x i d e ; — t h e n j u s t a c i d w i t h h y d r o c h l o r i c ( p r e s e n c e o f even s m a l l amounts o f a c e t i c acid interfere with the t e s t ) . distilled. until  150 c c o f d i s t i l l a t e were c o l l e c t e d , o r more,  the d i s t i l l a t e  phenol*  The m i x t u r e was steam  showed o n l y v e r y s l i g h t t r a c e s of  The d i s t i l l a t e was d i l u t e d w i t h d i s t i l l e d  t o 250 c c . and t h o r o u g h l y mixed. quite obvious.  water  The odor of p h e n o l was  A standard s o l u t i o n of phenol c o n t a i n i n g  ,0002344g. p e r c c . was p r e p a r e d .  E q u a l volumes of t h i s  and t h e s o l u t i o n o f unknown were p l a c e d i n s m a l l homemade comparison  tubes and t o t h e s e , e q u a l volumes of bromine  28. w a t e r were added. D i s t i l l e d w a t e r was added t o the one w h i c h was most c l o u d y u n t i l t h e two were e q u a l l y  cloudy.  T h i s c o m p a r i s o n , made Toy l o o k i n g t h r o u g h t h e tubes i n t o d i f f u s e l i g h t , gave a c c u r a t e r e s u l t s p r o v i d e d t h e t e s t was made s p e e d i l y , i . e . b e f o r e c o a g u l a t i o n of the p r e c i p i t a t e took place.  Prom t h e volume of l i q u i d i n each tube,  the c o n c e n t r a t i o n o f p h e n o l i n t h e unknown s o l u t i o n c o u l d be c a l c u l a t e d f r o m t h e known c o n c e n t r a t i o n of the standard. Steam d i s t i l l a t i o n o f t h e r e a c t i o n m i x t u r e  provided  t h e o n l y s u c c e s s f u l means of s e p a r a t i n g p h e n o l f r o m t h e o t h e r products.  P r e f e r e n t i a l a d s o r p t i o n o f p h e n o l on c h a r c o a l  was t r i e d , b u t t h e c o n c e n t r a t i o n o f p h e n o l was so l o w t h a t t h e scheme d i d n o t meet w i t h  success.  I n some e x p e r i m e n t s a r e c t i f i e d c u r r e n t was used. A t a n t a l u m m e t a l e l e c t r o d e was t h e r e c t i f i e r .  A small  s h e e t o f t a n t a l u m was p l a c e d i n t h e c e l l and 90 v o l t s DC were a p p l i e d f o r 2 h o u r s .  The l a r g e f a l l o f p o t e n t i a l a t  t h e s u r f a c e o f t h e r e c t i f i e r caused s p a r k i n g a t the electrode.  A f t e r 2 hours o n l y .o4 amperes were f l o w i n g .  The t a n t a l u m became covered  with a blue deposit.  A PD of  9 v o l t s was a p p l i e d f o r 18 h o u r s , a f t e r w h i c h time no c u r r e n t was f l o w i n g w h i c h was l a r g e enough t o be measured on t h e ammeter.  T h i s e l e c t r o d e was t h e n used as a r e c t i f i e r .  The c e l l was p l a c e d i n an AC c i r c u i t t a k e n from a t r a n s f o r m e r . 15.2 v o l t s AC gave a c u r r e n t w h i c h measured 60 m i l l i a m p e r e s .  29.  on a DC m i l l i a r o m e t e r . I n some experiments  the d i r e c t i o n of f l o w of current  was r e v e r s e d i n t h e m i d d l e o f t h e e l e c t r o l y s i s i n t h e hope t h a t o x i d a t i o n o f r e d u c t i o n p r o d u c t s m i g h t y i e l d some compounds d i f f e r e n t f r o m those o b t a i n e d by o x i d a t i o n of the o r i g i n a l r e a c t a n t .  These experiments  i n v o l v e d the  use o f a number o f d i f f e r e n t t y p e s o f c u r r e n t .  I f the  o r d i n a r y d i r e c t c u r r e n t be r e p r e s e n t e d by (a) i n F i g u r e 4. the o r d i n a t e i n d i c a t i n g t h e e x t e n t o f t h e charge on t h e e l e c t r o d e and t h e a b s c i s s a i n d i c a t i n g t i m e , then (b) r e p r e s e n t s t h e n a t u r e o f t h e c u r r e n t when c u r r e n t i s reversed.  The a l t e r n a t i n g c u r r e n t used by i t s e l f i s  r e p r e s e n t e d by ( c ) , and when used superimposed upon d i r e c t c u r r e n t , by (d) and ( e ) .  That o b t a i n e d w i t h t h e t a n t a l u m  e l e c t r o d e i s r e p r e s e n t e d by ( f ) . The  decomposition  p o t e n t i a l i n d i c a t e d by t h e r e d l i n e s need n o t n e c e s s a r i l y have t h e same v a l u e above as below t h e l i n e o f zero voltage (green).  The a c t u a l v a l u e f o r t h e d e c o m p o s i t i o n  p o t e n t i a l was n o t o b t a i n e d .  A t t e m p t s were made t o measure  i t i n a s o l u t i o n o f 50 c c . o f benzene i n 100 c c . of a c e t i c a c i d , b u t t h e r e was no sudden change o f s l o p e o f the v o l t a g e - c u r r e n t graph, as c a n be seen by t h e r e s u l t s recorded  i n t h e next s e c t i o n ; hence t h e r e seemed t o be no  p a r t i c u l a r v a l u e f o r t h e d e c o m p o s i t i o n p o t e n t i a l over t h e range s t u d i e d .  CURRENT GRAPHS (a)  Simple D i r e c t Current.  (b) D i r e c t C u r r e n t Reversed.  (c)  Simple A l t e r n a t i n g Current.  (d) A l t e r n a t i n g c u r r e n t s u p e r i m p o s e d on Direct.  (e) A l t e r n a t i n g c u r r e n t s u p e r i m p o s e d on a larger D i r e c t Current,  (f) I n t e r m i t t e n t current obtained w i t h the Tantalum e l e c t r o d e s . Green L i n e s ; - - Z e r o v o l t a g e . Red L i n e s ; - - D e c o m p o s i t i o n p o t e n t i a l s , B l a c k l i n e s ; - - V a r i a t i o n o f c h a r g e on e l e c t r o d e s o r v o l t a g e . Ordinates;--Voltage or charge. Abscissae;--Time.  Figure 4  30. IT. R e s u l t s . The  c u r r e n t - v o l t a g e curve f o r a s o l u t i o n of 50 c c .  benzene i n 100 c c . a c e t i c a c i d i s g i v e n i n Graph I .  Where  a l c o h o l i s s u b s t i t u t e d f o r a c e t i c a c i d , the r e s u l t s shown by Graph I I , a c i d ( w i t h HC1)  s o l u t i o n and by Graph I I I ,  b a s i c ( w i t h NaOH) s o l u t i o n , are o b t a i n e d . t h e l a s t two graphs t h e r e seems t o be a a t about 1.6 curve  In the case of decomposition  v o l t s but w i t h benzene i n a c e t i c a c i d the  i s q u i t e smooth. The  only other products  examined c l o s e l y were those  o b t a i n e d f r o m e x p e r i m e n t s 1, 2, and 17. products  from Experiment  2 had s t o o d f o r some time (about  2 m o n t h s ) , many c r y s t a l s s e p a r a t e d separated  A f t e r the  out.  These were  f r o m the mother l i q u o r and washed w i t h e t h e r ,  i n w h i c h they a r e i n s o l u b l e , d r i e d between t o w e l s d e s i c c a t e d over anhydrous c a l c i u m c h l o r i d e f o r two  and weeks.  P o u r samples were weighed out i n t o d e s i c c a t e d , weighed crucibles.  A f t e r h e a t i n g f o r 12 hours a t 104°C. they were  r e w e i g h e d and a g a i n a f t e r 1 hour a t 150°C.  A l l four  w e i g h t s check c l o s e l y w i t h what i s t o be e x p e c t e d from the decomposition  of sodium a c e t a t e w i t h two moltecules of  a c e t i c a c i d of c r y s t a l l i z a t i o n sodium a c e t a t e .  t o the o r d i n a r y anhydrous  Treatment w i t h excess h y d r o c h l o r i c a c i d  f o l l o w e d by d r y i n g and r e w e i g h i n g  gave a r e s u l t which  checked c l o s e l y w i t h t h a t expected from the c o n v e r s i o n sodium a c e t a t e t o sodium c h l o r i d e .  of  The c r y s t a l s d i s s o l v e d  -4-,  I  i  I* 6  <5R  u  31. r e a d i l y i n w a t e r g i v i n g an a c i d s o l u t i o n . s o l u t i o n was weight  Sodium h y d r o x i d e  s t a n d a r d i z e d and used to t i t r a t e a known  o f the c r y s t a l s .  Prom the n o r m a l i t y of the  and the volume u s e d , the t i t r a t i o n e q u i v a l e n t was he 101.6.  Prom t h i s d a t a i t was  solution found,to  e v i d e n t t h a t the  c r y s t a l l i n e substance was CH C00Ha."CH C00H. 3  3  This  substance  has been r e c o g n i s e d f o r some t i m e , and of c o u r s e , i s not a p r o d u c t of e l e c t r o l y s i s .  But c r y s t a l s o b t a i n e d i n a  s i m i l a r manner from E x p e r i m e n t 1. f a i l e d t o c o r r e s p o n d  to  any p r e v i o u s l y r e c o g n i z e d compound. These c r y s t a l s , were, l i k e those of Experiment 2, i n s o l u b l e i n e t h e r , carbon t e t r a c h l o r i d e , o n l y s l i g h t l y s o l u b l e i n 95% e t h y l a l c o h o l , but v e r y s o l u b l e i n water. T h e i r aqueous, s o l u t i o n was  acid.  However, t i t r a t i o n showed  an e q u i v a l e n t weight  of 151.  O b v i o u s l y t h i s i s not  same compound as was  o b t a i n e d i n E x p e r i m e n t 2 though b o t h  compounds have much i n common. an inflammable  gas, (acetone  the  B o t h gave o f f , on h e a t i n g *  i n the case of Experiment 2 ) ,  and l e f t a r e s i d u e of sodium c a r b o n a t e .  A d d i t i o n of  concentrated sulphuric a c i d to f r e s h c r y s t a l s l i b e r a t e d a c i d which,  i n s m e l l , resembled  closely, acetic  an  acid.  Hence the compound i n q u e s t i o n appears t o be the sodium s a l t of an o r g a n i c a c i d t o g e t h e r ?*rith a c e t i c a c i d of crystallization.  When the c r y s t a l s a r e heated g e n t l y , i t  seems t h a t the a c e t a t e r a d i c a l u n i t e s w i t h the sodium i o n g i v i n g sodium a c e t a t e ^ — e x c e s s  acids being driven o f f .  The  32. residue  m e l t s a t 312°C as does sodium a c e t a t e .  Vacuum  d i s t i l l a t i o n of t h e s e c r y s t a l s t o g e t h e r w i t h s u l p h u r i c a c i d , y i e l d e d a t r a c e of l i q u i d w h i c h had t h e s m e l l of a c e t i c a c i d , b u t u n m i s t a k a b l y , a l s o t h a t of v a n i l l a . how v a n i l l i n was  Just  formed from benzene, i s u n c e r t a i n , but i t  i s p o s s i b l e t h a t i s o e u g e n o l was an i n t e r m e d i a t e p r o d u c t as v a n i l l i n has been o b t a i n e d f r o m i s o e u g e n o l e l e c t r o l y t i c a l l y , ^ The m e l t i n g p o i n t of t h e c r y s t a l s was tl-94°C and  decomposition  t o o k p l a c e a t 160-162°C. The unknown o r g a n i c a c i d r a d i c a l of t h i s compound may  be t h e same as t h a t o b t a i n e d i n a d i f f e r e n t manner  i n Experiment  17.  A f t e r a l l the a c i d has been n e u t r a l i z e d  w i t h sodium h y d r o x i d e and t h e p h e n o l had been steam d i s t i l l e d the r e s i d u e was a l l o w e d t o c o o l . formed.  Crystals 8 x 1 x 1  cm*  These t r e a t e d i n a manner s i m i l a r t o t h e treatment  d e s c r i b e d above f o r c r y s t a l s from Experiment be something  2, proved t o  o t h e r than pure h y d r a t e d sodium a c e t a t e ,  though b o t h sodium and a c e t a t e r a d i c a l s w e r e i n v o l v e d i n the make up o f t h i s c r y s t a l l i n e  substance.  The y i e l d s of p h e n o l and the c o n d i t i o n s under w h i c h t h e y were o b t a i n e d i n the v a r i o u s experiments a r e i n d i c a t e d i n the f o l l o w i n g t a b l e .  1. D. R. P. 92007 (1895). and see a l s o Trans Am. S o c , 42, 273, (1922).  Electrochem.  33. DC.  Dia.VoltsjampsjVoltsjAmpg;Timento houragm. .05 2 N i . R No DLL. NaOH 6  AC.  .07  II  6  .12  2  .0192  2  .019J2  2  .02 1.3  2  II  i¥ i*'  II «»  II I I  2 "  13  II  »  AIC-H2SO4  S" HOAc Olac  44 dlu ""  2.6 .05 7.4  no  V o l V o l . of enzHOAc ene.  II  1  !  II  II  sliglr qual No  25  50  50  100  •»  II  ti  II  11  II  11  II  .08%  11  II  ,  9 »  II II  24"  II II  30"  ti  II  48"  II  w  2.5 . 0 1 6  28Pt  n n  no  20  40  n  36"  "yes "  qual  20  40  slight qjaal slight s l i ^ht no qual  11  11  tt  II  11  11  50  100  12 12  .07  1.44 • OOSJ  3  .07  slight qualit more  -lldaysNi"  "  -7 daysCu"  "  l l d a y s "" "  15.  2 daysTa&pt*  1.4  9  5days n i c h r " "  2.  10  3days Cu nd'  .06  slight qual  11%  it  4 "  Pt  it  2 "  II  ii  i-  Pt&Pe»'»  "  it  •3i"  Cu  ""  "  .29%  "  11  11  .12%  -10  3 "  I"  II  II  .00  II  II  I  «  .00  100  34. No.olf Exp  D C A.C. T piaH cc.of cc.of Amps VoltsAmpsTimeAnodephr e l e c t r o l y tephenolBen zen HOAo hours  18. 2  3dayjs Cu y e s H O A c Qiao > . 22%j 20  19. 2  24ho|ur " it  .00  20. 4  8 "  .00  21&;  it  23. 30&ufc  5i»  24. 40&u >  l|"  25. 15-40  2i  28. 10-30  1  29. 15-30  ii  30. 19-40  l  31. 19- 4<|>  ii"  32. 20  i "  33. 15-20  if"  34. 20-  i.e  2$ 35. 20- 2t 1.  yes  II  w  .50% Pt  M  n  if" i£"  Cu Pt  ome CuS04 ess  1.17%  10  1.76%  5  HOAo Glac  1.56%  5  J  II  II  n  ti  it  1.5%  3  ti  it  1.17%  3  1.0%  3  1.  5  with CttSO  with aftm. 1.76% meta vanadate 1.5%  5 5  40  s  35. V. D i s c u s s i o n of R e s u l t s . As can "be seen from the r e s u l t s , the  superimposition  of a l t e r n a t i n g c u r r e n t on d i r e c t c u r r e n t does not seem t o i n c r e a s e the y i e l d of p h e n o l .  F u r t h e r , the h i g h e r  v o l t a g e used, ( w i t h i n r e a s o n a b l e i s obtained.  the  l i m i t s ) , t h e more p h e n o l  T h i s c o r r e s p o n d s t o t h e f i n d i n g s of  Stocker  and T o n o l i when they e l e c t r o l i z e d benzene s u l p h o n i c a c i d . ^~ I t w i l l be n o t e d t o o * t h a t the presence of a s m a l l q u a n t i t y of the s a l t s of c o p p e r , i r o n or vanadium i n c r e a s e s  the  y i e l d of p h e n o l , but t h a t a l a r g e q u a n t i t y of any of  these  s a l t s ( e s p e c i a l l y of the f i r s t t w o ) , causes excess o x i d a t i o n .  1. Rend Soc. Chim. I t a l . F a s c a . 2  (1912).  36. VI.  Summary. 1. A f a i r l y d e t a i l e d summation o f t h e f a c t o r s w h i c h influence  e l e c t r o l y s e s such as t h i s one» has been  made • 2. P h e n o l has been o b t a i n e d e l e c t r o l y t i c a l l y from benzene;  t h e h i g h e s t y i e l d , however, was 1.76%.  3. T h i s h a s , t o g e t h e r w i t h t h e r e s u l t s o f F i c h t e r and U h l r e f e r r e d t o on page 2, p r o v i d e d e v i d e n c e the p r e d i c t i e n o f s e v e r a l o r g a n i c that phenol i s the f i r s t  favoring  electrochemistB  electro-oxidation  p r o d u c t o f benzene. 4. I n t h e s e e x p e r i m e n t s , t h e s a p e r i r a p o s i t i o n of A l t e r n a t i n g Current d i d not increase  the y i e l d  of p h e n o l . 5. The p r e s e n c e i n t h e e l e c t r o l y t e , o f s m a l l q u a n t i t i e s of s a l t s of m u l t i v a l e n t metals i s beneficial. 6.  A high voltage  i s preferable  t o a low v o l t a g e i f  phenol i s desired. 7.  E l e c t r o l y s i s of benzene produces an e q u i l i b r i u m mixture of phenol w i t h other products.  The  concentration  of p h e n o l was p r o b a b l y never more t h a n 2% o f the o r i g i n a l concentration  o f benzene.  37.  In c o n c l u s i o n I w i s h t o e x p r e s s my thanks t o D r . R. H. C l a r k f o r k i n d l y c r i t i c i s m and t h e many h e l p f u l s u g g e s t i o n s o f f e r e d throughout investigations.  these  38 VII.  Bibliography.  B.  THE EFFECT OF CERTAIN CHEMICALS ON THE HTOROLTTIC ACTIVITY OF RICINUS AND PORK PANCREAS LIPASE.  39, THE EFFECT OP CERTAIN CHEMICALS ON THE HYDROLYTIC ACTIVITY OP RICINUS AND  PORK PANCREAS LIPASE.  F o l l o w i n g up t h e work done i n t h e s e l a b o r a t o r i e s  on  the a c t i v a t i o n of amylase, e x p e r i m e n t s were c a r r i e d out to d i s c o v e r the influence  of c e r t a i n c h e m i c a l s , e s p e c i a l l y  o r g a n i c c h e m i c a l s , on t h e h y d r o l y t i c a c t i v i t y of l i p a s e .  1  C e r t a i n c h e m i c a l s have been f o u n d c a p a b l e of s h o r t e n i n g the dormant p e r i o d of seeds.  The above mentioned work has  shown t h a t t h i s may be due t o t h e a c t i v a t i o n of amylase i n the  s e e d , r e s u l t i n g i n the p r o d u c t i o n of a hexose  which  s e r v e s as a s o u r c e of f o o d f o r the growing embryo.  I n the  case o f c e r t a i n s e e d s , i t may be t h a t t h e dormant p e r i o d  may  be b r o k e n p r e m a t u r e l y , by t h e use of c e r t a i n c h e m i c a l s w h i c h activate lipase.  L i p a s e i s known t o be p r e s e n t i n an  active  f o r m i n g e r m i n a t i n g endosperms of o i l y s e e d s , b u t n o t i n the r e s t i n g s e e d s .  F u r t h e r m o r e , l i p a s e o c c u r s i n many  d i f f e r e n t forms w i t h i n t h e a n i m a l body. tuberculosis serum l i p a s e .  a r e u s u a l l y accompanied  S e r i o u s cases of  by low v a l u e s o f  The l i p a s e i n h i b i t s the growth of the  t u b e r c l e b a c i l l u s by d e s t r o y i n g the waxy o r f a t t y c o v e r i n g w h i c h i s c h a r a c t e r i s t i c of Mycobacterium t u b e r c u l o s i s .  If  an a c t i v a t o r f o r serum l i p a s e c o u l d be f o u n d , i n j e c t i o n of t h i s a c t i v a t o r , i n t o the b l o o d stream, might r e s u l t i n 1. T r a n s . Roy. Soc. Canada; XXV S e c t I I I , 99 (1931).  40. h e l p i n g t h e body t o w i n t h e b a t t l e a g a i n s t t h e t u b e r c l e bacillus. P r e v i o u s Work; Much work has a l r e a d y been done a l o n g t h i s l i n e . r e s u l t s are very c o n f l i c t i n g .  Palmer  1  The  reports that with  c o m m e r c i a l l i p a s e ( s o u r c e n o t s t a t e d ) , formaldehyde i n c o n c e n t r a t i o n s between 1 p a r t i n 1000 and 1 p a r t i n 1500 gave a 1 6 % i n c r e a s e i n a c t i v i t y . concentrations  Mercuric chloride i n  .1 t o . 3 % C o m p l e t e l y i n h i b i t e d t h e h y d r o l y s i s .  A c e t o n e .6% t o 1 2 % i n h i b i t s by 11%-24%.  I o d i n e .09% r e t a r d s  the r a t e 9 6 % and Bromine .25% r e t a r d s a c t i v i t y by 93.2% H y d r o c h l o r i c a c i d has been r e p o r t e d as an a c t i v a t o r . Enzymes Used. I n t h e s e s t u d i e s , two l i p a s e s were u s e d . animal  i n source.  I t was p r e p a r e d  One was  T h i s was s u p p l i e d by E i m e r & Amend.  from pork pancreas.  The pancreas was vacuum  d r i e d a t a l o w t e m p e r a t u r e , and d e f a t t e d w i t h b e n z o l . B e n z o l was removed i n vacuo. and s i f t e d .  The p r o d u c t  was then powdered  The o t h e r l i p a s e was a p l a n t l i p a s e .  Castor  o i l b e a n s , ( R i c i n u s Z a n z i b a r i e n s i s . , m i x e d ) , were germinated by k e e p i n g week.  t h e seeds i n a m o i s t c o n d i t i o n a t 80°P f o r one  The seeds were s h e l l e d by hand and t h e endosperms  were c o a r s e l y ground and washed once w i t h e t h e r . 1. J o u r a . Am. Chem. S o c , 44, 1527, (1922). 2. J o u r n . Am. Chem. S o c , 4 3 , 2664,  (1921).  T&JES  material  41. was e x t r a c t e d i n a S o x h l e t w i t h e t h y l e t h e r f o r one week. The o i l f r e e m a t e r i a l was a i r d r i e d and t h e n p l a c e d i n a vacuum d e s i c c a t o r over c a l c i u m c h l o r i d e f o r t h r e e weeks. T h i s d r i e d p r o d u c t was powdered i n a m o r t a r and passed t h r o u g h a 100 mesh s i e v e . Preparation of Substrate. G o l d drawn c a s t o r o i l was t h e s u b s t r a t e used. s u s p e n s i o n of t h e o i l was made w i t h gum a c a c i a . of powdered gum a c a c i a was mixed t h o r o u g h l y  A  ,55grams  i n a mortar  w i t h 90 c c . of c a s t o r o i l , t i l l an o i l y p a s t e r e s u l t e d . Water was added i n 5 c c . q u a n t i t i e s w i t h thorough m i x i n g between each a d d i t i o n .  A f t e r about 100 c c of w a t e r has  been a d d i d , t h e m i x t u r e  was d i l u t e d t o 2500 c c .  g i v e s a s t a b l e e m u l s i o n of 3,2% o i l i n w a t e r .  This  The  e m u l s i o n s p r e p a r e d i n t h i s way were f o u n d t o be much s u p e r i o r to those prepared according  t o d i r e c t i o n s i n the l i t e r a t u r e  where t h e gum a c a c i a i s h y d r a t e d  b e f o r e a d d i t i o n of t h e o i l .  Method, 75 c c . p o r t i o n s of t h i s c a s t o r o i l m i l k were p l a c e d i n 125 c c . E r l e n m e y e r f l a s k s .  The f l a s k s were p r e v i o u s l y  t r e a t e d t o remove t r a c e s of d i - o r m u l t i - v a l e n t s a l t s s u c h as m e r c u r i c the g l a s s . this"milk  M  s a l t s , w h i c h might be on t h e s u r f a c e s of  3 grams of l i p a s e were suspended i n 100 c c of and 3 c c . of t h e s u s p e n s i o n was added t o the  75 c c . p o r t i o n s of " m i l k " .  The c h e m i c a l s  were t h e n added,  except t o t h e c o n t r o l s - - a n d a l l f l a s k s were i n c u b a t e d a t 9  37°C.  T i t r a t i o n s were made on 25 c c . p o r t i o n s f r o m 24 t o  42. 96 h o u r s l a t e r ,  '•'•'he e x t e n t of h y d r o l y s i s was  ascertained  by t i t r a t i o n of the f a t t y a c i d s p r o d u c e d , w i t h .1 Normal sodium h y d r o x i d e as an end p o i n t .  s o l u t i o n , u s i n g a deep r e d of p h e n o l p h t h a l e i n A b u r e t t e of s m a l l d i a m e t e r  a c c u r a t e r e a d i n g s of s m a l l volumes of sodium solution.  permitted hydroxide  A l l t i t r a t i o n v a l u e s were compared w i t h  o b t a i n e d from (1) enzyme p l u s s u b s t r a t e w i t h o u t  those  chemicals  added, (2) s u b s t r a t e p l u s c h e m i c a l w i t h o u t enzyme added, (3) s u b s t r a t e i n w a t e r w i t h o u t e i t h e r enzyme or c h e m i c a l . Results• C h e m i c a l and Concentration Hydrochloric a c i d . .023% Lactic .2%  acid  E f f e c t on R i c i n u s lipase decreases  activity  a l m o s t complete inhibition.  E f f e c t on Pacreas lipase decreases a c t i v i t y markedly almost complete inhibition.  I o d i n e aqueous .0019%  marked i n h i b i t i o n f o r f i r s t 24 hours f o l l o w e d by a 20% i n c r e a s e otwr c o n t r o l s a f t e r 96 h o u r s .  Bromine aqueous .125%  same a c t i o n as f o r i o d i n e .  Acetone 5% and down  i n h i b i t s 80% and down  E t h y l b e n z y l ketone i n h i b i t s .2%  40%  i n h i b i t s 60% down, inhibits  40%  Isobutyl cresol k e t o n e ,2%  i n h i b i t s 5% and l e s s  i n h i b i t s 5% and  Methyl isobutyl c r e s o l ketone ,2%  E f f e c t s m a l l , semetimes a c c e l e r a t e s by 5%.  Sometimes a c c e l e r a t e s by 5%,  less.  43 C h e m i c a l and Concentration .  E f f e c t on R i c i n u s lipase.  E f f e c t on Pancreas lipase.  Formaldehyde Technical .1%  i n h i b i t i o n 80%  Cinnamic aldehyde .005—.1%  marked decrease i n b o t h c a s e s .  Hydrocinnamic aldehyde .002--.05%  decrease  C r o t o n i c Aldehyde .002%—.05%  complete t o 1 0 %  Acrylic .02%  complete  aldehyde  inhibition  decrease  inhibition  inhibition  Acetaldehyde .02%  decrease  Paraldehyde .02%  s l i g h t deciease  Benzaldehyde .1% & less  decrease  decrease  decrease  decrease  decrease  decrease  Furfural .002%—.05% I s o "butyl Aldehyde .002%-.05% Salicylic aldehyde .002%-.05% Mercuric chloride .01% .003% Potassium thiocyanate 1% f r e s h s o l u t i o n old solution f r e s h from d i f f e r e n t souree  decrease  decrease slight  decrease  decrease  inhibits 95% 90% 120%  increase  decrease decrease  30%  80%  decrease decrease decrease.  44. C h e m i c a l and Concentration.  E f f e c t on R i c i n u s lipase  Ethylene c h l o r hydrin .3% Thiourea .15% Cystein 1/15 cone o f sat. s o l u t i o n  E f f e c t on Pancreas lipase.  decrease  decrease  decrease  decrease  decrease  S k a t o l (Sat) 1—1/5 saturated  decrease  decrease  decrease  Pyridene .05%--.002%  increase i n low c o n c e n t r a t i o n s .  A compound w i t h t h e f o r m u l a H-U CsO  i  i  C H - S-6 0"°% i n c o n c e n t r a t i o n s of .02% gave d e c r e a s e s i n b o t h c a s e s . H C-H Conclusions. 2  5  I t w i l l he o b s e r v e d , t h a t as a whole aldehydes cause a decrease i n a c t i v i t y l i k e w i s e appear  i n the concentrations  t o decrease t h e a c t i v i t y .  used.  Ketones  The double  bond i n an aldehyde seems t o have an a p p r e c i a b l e e f f e c t P o t a s s i u m t h i o c y a n a t e d e c r e a s e s t h e a c t i v i t y of a n i m a l l i p a s e , b u t sometimes i n c r e a s e s the a c t i v i t y of R i c i n u s lipase.  T h i s may be due t o t h e a c t i o n of t h e K  t h a n t o t h e 8GM~  4  ion rather  i o n . O l d s o l u t i o n s seem t o c o n t a i n  some d e c o m p o s i t i o n p r o d u c t of KSC1 which i n h i b i t s  activity.  F u r t h e r , d i f f e r e n t samples o f t h e m a t e r i a l have d i f f e r e n t e f f e c t s i n d i c a t i n g that the C P . m a t e r i a l contains  varying  45. q u a n t i t i e s of i m p u r i t y .  Hydrochloric i n the concentrations  f o u n d by Palmer t o produce a c t i v a t i o n ( n o t u s i n g an e m u l s i o n ) d i d n o t cause an a c t i v a t i o n w i t h t h e s u s p e n s i o n . L a c t i c a c i d i s c o n s i d e r e d by some ay t h a t substance w h i c h c o n v e r t s t h e zymogen t o l i p a s e i n p l a n t s ' seeds.  However  i n v i t r o a l m o s t complete i n h i b i t i o n r e s u l t s w i t h even reasonably  small concentratidns.  The r e s u l t s  w i t h t h e f r e e halogens are very i n t e r e s t i n g .  obtained I t w i l l be  observed t h a t much l a r g e r q u a n t i t i e s o f bromine a r e r e q u i r e d t o g i v e t h e same e f f e c t as s m a l l q u a n t i t i e s o f iodine.  

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