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Determination of the crystal structure of three organic compounds by X-ray diffraction 1970

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THE DETERMINATION OF THE CRYSTAL STRUCTURE OF THREE ORGANIC COMPOUNDS BY X-RAY DIFFRACTION BY ROGER MICHAEL SCHAFFRIN M.D., University of Saskatchewan, 1963 B.A., University of Saskatchewan, 1965 A THESIS SUBMITTED IN THE REQUIREMENTS DOCTOR OF PARTIAL; FULFILMENT OF FOR THE.DEGREE OF PHILOSOPHY i n the Department of CHEMISTRY We accept t h i s thesis as conforming to the required standard THE UNIVERSITY OF BRITISH COLUMBIA July, 1970 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 t he r e q u i r e m e n t s f o r an advanced degree a t t h e U n i v e r s i t y o f B r i t i s h C o l u m b i a , I ag ree t h a t t h e 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 s t u d y . I f u r t h e r ag ree t h a t p e r m i s s i o n 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 p u r p o s e s may be g r a n t e d by the Head o f my Depar tment o r by h i s r e p r e s e n t a t i v e s . I t i s u n d e r s t o o d t h a t c o p y i n g o r 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 no t be a l l o w e d w i t h o u t my w r i t t e n p e r m i s s i o n . Depar tment o f The U n i v e r s i t y o f B r i t i s h Columbia Vancouver 8 , Canada Date OcJ-cA^,, C . - i i - ABSTRACT Supervisor: Professor James Tr o t t e r The c r y s t a l structure of dibenzothiophene has been determined by X-ray d i f f r a c t i o n . Mo-K s c i n t i l l a t i o n counter data were used for a t h i s a n a l y s i s ; the s u l f u r atom p o s i t i o n was determined by means of a Patterson function; the carbon atoms were located from a Fourier synthesis, and the hydrogen atoms, from a diffe r e n c e synthesis. Refinement of p o s i t i o n a l and thermal parameters was by least-squares methods. The molecule i s s l i g h t l y folded, the dihedral angles between the five-membered ring and the six-membered rings being 0.4° and 1.2°. The bond distances and valency angles are s i m i l a r to those i n re l a t e d o molecules. The C-S bond length i s 1.740 A, and the C-S-C angle i s 91.5°. The c r y s t a l structure of DL-ornithine hydrobromide has been determined by means of v i s u a l Cu-K data. The bromine ion p o s i t i o n a ; was found by Patterson methods; carbon, nitrogen, and oxygen atoms were located on Fourier summations and the hydrogen atoms, on a difference synthesis. The p o s i t i o n a l and thermal parameters were refined by least-squares. The ornithine molecule i s a zwitterion, with both nitrogens accepting protons. The mean bond distances are o , o o C-0, 1.249 A; C-N, 1.469 A; C-C, 1.532 A. The structure i s held together by a system of N—H 0 (2.84, 2.84, 2.89 A) and N—H...Br O (3.29, 3.36,.3.46 A) hydrogen bonds. The c r y s t a l and molecular structure of histamine diphosphate monohydrate has been determined with s c i n t i l l a t i o n counter Mo-K data. J a - i i i - The positions of the phosphorus atoms were determined by Patterson methods; the carbon, nitrogen and oxygen atoms were located by means o Fourier syntheses; the hydrogen atoms were found on a differe n c e synthesis. The thermal and p o s i t i o n a l parameters were r e f i n e d by least-squares. The atoms of t h i s histamine cation l i e i n two almost perpendicular planes, the plane of the imidazole r i n g and that of the side chain. The bond lengths and angles are s i m i l a r to the correspond ing values i n h i s t i d i n e hydrochloride monohydrate. The dimensions of o o the two P0 2(OH) 2~ ions are P-0 1.51 A, P-OH 1.57 A, O-P-0 115.5°, and HO-P-OH 107.0°. The most important feature of the packing i s a complex system of 0-H...0 and N-H...0 hydrogen bonds. - i v - TABLE OF CONTENTS Page TITLE PAGE i ABSTRACT i i TABLE OF CONTENTS i v LIST OF TABLES v i LIST OF FIGURES v i i ACKNOWLEDGEMENTS v i i i GENERAL INTRODUCTION 1 PART I. THE DETERMINATION OF THE STRUCTURE OF DIBENZOTHIO- PHENE 2 A. INTRODUCTION , 3 B. THE STRUCTURE OF DIBENZOTHIOPHENE 3 Experimental 3 Structure Analysis 5 Results and Discussion 12 PART I I . THE DETERMINATION OF THE STRUCTURE OF DL-ORNITHINE HYDROBROMIDE 18 A. INTRODUCTION 19 B. THE STRUCTURE OF DL-ORNITHINE HYDROBROMIDE 19 Experimental 19 Structure Analysis 20 Results and Discussion 22 PART I I I . THE DETERMINATION OF THE STRUCTURE OF HISTAMINE DIPHOSPHATE MONOHYDRATE A. INTRODUCTION B. THE STRUCTURE OF HISTAMINE DIPHOSPHATE MONOHYDRATE Experimental Structure Analysis Results and Discussion BIBLIOGRAPHY - v i - LIST OF TABLES Table Page Dibenzothiophene 1. F i n a l p o s i t i o n a l and thermal parameters 8 2. Measured and calculated structure factors 10 3. Displacements from mean planes 13 4. Bond distances and angles i n dibenzothiophene and rel a t e d molecules 14 DL-Ornithine Hydrobromide 5. Measured and calculated structure factors 23 6. F i n a l p o s i t i o n a l and thermal parameters 26 7. Bond lengths and angles 27 8. Hydrogen atoms 28 9. Carbon-oxygen bond lengths i n some amino acids 29 10. Carboxylate bond angles i n ornithine and l y s i n e derivatives 30 11. Carbon-carbon-nitrogen angles i n ornithine and l y s i n e derivatives 30 12. Carbon-carbon-carbon angles i n ornithine and l y s i n e d e r i v a t i v e s 31 13. Hydrogen bonds 35 Histamine Diphosphate Monohydrate 14. F i n a l p o s i t i o n a l and thermal parameters 42 15. Measured and calculated structure factors 47 16. Bond distances and angles 50 17. Hydrogen bonds 57 18. Environments of atoms involved i n hydrogen bonding... 58 - v i i - LIST OF FIGURES Figure Page Dibenzothiophene 1. (a) Perspective drawing showing atom numbering 7 (b) Projected difference synthesis 7 2. Projected electron density d i s t r i b u t i o n .9 3. Packing diagram 17 DL-Ornithine Hydrobromide 4. (a) Projected electron density d i s t r i b u t i o n 24 (b) Perspective drawing showing atom numbering 24 5. Packing diagram 32 Histamine Diphosphate Monohydrate 6. Projected difference synthesis 41 7. Projected electron-density d i s t r i b u t i o n 44 8. Perspective drawing showing atom numbering 45 9. Packing diagram 55 10. Hydrogen bonding scheme 56 - v i i i - ACKNOWLEDGEMENTS I want to thank Professor James Tr o t t e r for h i s help and for h i s great patience. While working under him I grew to respect him very much f o r his gentle manner and s c i e n t i f i c thoroughness. I should l i k e to thank Dr. R.J. Zwarich for suggesting the analysis of dibenzothiophene and for providing me with a sample of th i s compound. For the assistance which I received from the University of B r i t i s h Columbia Computing Centre I am g r a t e f u l . F i n a l l y I wish to thank the Medical Research Council of Canada for providing Medical Research Fellowships f or the academic years 1965-1967. - 1 - GENERAL INTRODUCTION In 1912 von Laue suggested that c r y s t a l s should d i f f r a c t X-rays; th i s was confirmed experimentally by F r i e d r i c h and Knipping. Bragg elucidated the mathematical i n t e r p r e t a t i o n of X-ray d i f f r a c t i o n and determined the f i r s t c r y s t a l structure by X-ray d i f f r a c t i o n i n 1913. Since that time X-ray crystallography has been used to inve s t i g a t e the structure of matter on an atomic scale. With the advent of automated spectrogoniometers and d i g i t a l computers, structures of r e l a t i v e l y great s i z e and complexity, such as hemoglobin and myoglobin, have been examined by means of X-ray crystallography. Of the various a n a l y t i c a l tools a v a i l a b l e to the chemist, c r y s t a l l o - graphy i s the only one that gives a complete three-dimensional p i c t u r e of the molecule. The de t a i l e d molecular structure, i n turn, i s often necessary f o r an understanding of the p h y s i c a l , chemical and b i o l o g i c a l properties of substances occurring i n l i v i n g organisms. Various amino acids, hormones, enzymes and proteins have been studied by means of X-ray crystallography. It was with the aid of t h i s t o o l that the Watson- Crick model for DNA was developed. Since then,the molecular approach to b i o l o g i c a l systems has gained tremendously i n favor. This thesis concerns i t s e l f with the determination, by s i n g l e - c r y s t a l X-ray d i f f r a c t i o n , of the structures of three organic compounds. Since the methods of gathering the data, deriving structure factors,; solving the structures by Patterson and Fourier techniques as w e l l as the subsequent.refinement by least-squares methods are adequately described i n many reference books (1,2,3), they w i l l not be described i n d e t a i l i n the t h e s i s . The compounds analysed are l i s t e d i n order of increasing d i f f i c u l t y and medical importance. PART I THE DETERMINATION OF THE STRUCTURE OF DIBENZOTHIOPHENE - 3 - A. INTRODUCTION In 1955 Burns and I b a l l (4) reported the c r y s t a l and molecular structure of fluorene, C^H^n. Kurahashi et a l (5) and L a h i r i (6,7) determined the structure of carbazole, C 1 0H N, between 1966 and 1969. F i n a l l y , McCullough et a l (8) reported the c r y s t a l and molecular structure of dibenzoselenophene, C.„H Se, i n the winter of 1969. I t i z o seemed of i n t e r e s t therefore to determine the structure of dibenzothio- phene C^2^gS. B. THE STRUCTURE OF DIBENZOTHIOPHENE Experimental When sublimed at atmospheric pressure i n a stream of nitrogen, dibenzothiophene forms t h i n , c o l o r l e s s plates which are elongated along b, with (102) well developed and smaller (100) and (001) forms. The unit c e l l parameters and space group were determined from various photographic and diffractometer measurements. o , C r y s t a l data (A, Mo-K = 0.7107 A). Dibenzothiophene, C.„H 0S; M = 184.3; mp = 99°C. o Monoclinic, a = 8.67 ± 0.01, b = 6.00 ± 0.01, c = 18.70 ± 0.02 A, 3 = 113.9 ± 0.1°. °3 U = 889.5 A . :.D = 1.35, Z = 4, D = 1.38. m x F(000) = 384. Absorption c o e f f i c i e n t f o r X-rays, u(Mo-K ) = 2.99 cm Absent r e f l e x i o n s : h0>! when £ i s odd, 0k0 when k i s odd. Space group is-•P2 1/c (C^, ) . The i n t e n s i t i e s of a l l r e f l e x i o n s with 2 6 (Mo-K )< 50° (minimum d, a o 0.84 A) were measured on a G.E. XRD 5 Spectrogoniometer, with s i n g l e C r y s t a l Orienter, using a s c i n t i l l a t i o n counter, Mo-K^ r a d i a t i o n (zirconium f i l t e r and pulse height analyser), and the moving-crystal moving-counter technique of Furnas (9). A l l the i n t e n s i t i e s were corrected for background r a d i a t i o n (approximately only a function of 8 ) and the structure amplitudes were derived as usual. The c r y s t a l , a square plate measuring 0.58 x 0.53 x 0.20 mm was mounted with b p a r a l l e l to the axis of the goniostat so that the cross section traversed by the X-ray was 0.58 x 0.20 mm. The following sources of error i n the measured structure factors were considered. F i r s t l y , taking the c r y s t a l as a cy l i n d e r with a mean diameter of 0.39 mm, uR i s 0.058 and the absorption c o r r e c t i o n factor A i s 1.10 and constant over the range of 6 = 0-25°; thus the maximum absorption ; error i s n e g l i g i b l e f o r the above range of 6 . Secondly, absorption errors due to non-uniformity of c r y s t a l dimension were estimated by considering the shortest (0.20 mm) and the longest (0.8 mm) path lengths i n the c r y s t a l . The absorption corrections f o r the correspond- ing structure factors are exp(2.99 x 0.02/2) and exp(2.99 x 0.08/2) or 1.03 and 1.13 re s p e c t i v e l y . Therefore, the maximum deviation from the mean correction i s less than 5%. Since the t o t a l maximum error i n F due to absorption i s 5% and since most of the errors w i l l be much o • r smaller than t h i s value, no corrections were made for absorption. - 5 - Structure Analysis The p o s i t i o n of the s u l f u r atom was determined from a three- dimensional Patterson synthesis (0.156, 0.167, 0.135) and structure factors were calculated for a l l the three-dimensional data f o r s u l f u r only, using s c a t t e r i n g factors from the International Tables for X-ray Crystallography 1962 (10) and an i s o t r o p i c thermal parameter of 4.0 A . One least-squares refinement reduced R to 0.56. A three-dimensional Fourier s e r i e s summed with phases based on the s u l f u r atom revealed the positions of a l l the carbon atoms. When these were introduced into the structure f a c t o r c a l c u l a t i o n s with s c a t t e r i n g factors from the °2 International Tables and B = 4.0 A , R dropped to 0.45. Further, refinement of the p o s i t i o n a l and i s o t r o p i c thermal parameters together with an o v e r a l l scale f a c t o r , proceeded by the method of block- 2 diagonal least-squares, the function minimized being Zw( jF q|-|F £|) . Since the structure factors were considered to be le a s t accurately measured f o r the very strong r e f l e x i o n s which are affected most by , absorption, and f o r the very weak and unobserved r e f l e x i o n s the i n t e n s i t i e s of which are close to that of background r a d i a t i o n , jthe weighting scheme employed was v*w~ = 1 i f | F q | <F , i/w" = | F |/F i f | F Q | > F where F was taken as 5. For unobserved r e f l e x i o n s i/w was 0.70. After fourteen i s o t r o p i c least-squares refinement cycles, R was 0.12 and s h i f t s i n p o s i t i o n a l and thermal parameters were small i n magnitude and random i n d i r e c t i o n , the largest s h i f t being le s s than ' one fourth of a. standard deviation. Further refinement commenced with anisotropic thermal parameters; seven anisotropic refinement cycles decreased R to 0.10. A three- dimensional difference synthesis summed at t h i s stage of the analysis - 6 - revealed a l l eight hydrogen atoms (Figure 1). Their peak electron °-3 densities varied between 0.4 and 1.0 eA . When these hydrogen atoms were introduced into the structure factor c a l c u l a t i o n s with s c a t t e r i n g °2 factors from the International Tables and B = 4.0 A , R f e l l to 0.09. During the subsequent three least-squares cycles the s h i f t s of the i s o t r o p i c thermal parameters of hydrogen atoms 1, 3, and 8 were large and p o s i t i v e . A second diff e r e n c e synthesis was prepared i n order to determine the precise positions of hydrogens 1, 3, and 8. A f i n a l series of f i v e least-squares cycles completed the refinement. During the l a s t cycle, parameter s h i f t s were small and nonsystematic, the largest s h i f t being one quarter of a standard deviation f o r the heavier atoms and one hal f of a standard deviation for the hydrogen atoms. The p o s i t i o n a l and thermal parameters of a l l the atoms as derived from the f i n a l least-squares cycle are given i n Table 1, together with t h e i r standard deviations computed from the inverses of the diagonal terms of the matrix of the least-squares normal equations. The atom numbering used i s shown i n Figure 1. The hydrogen atoms were assigned the numbers of the carbon atoms to which they are bonded. The f i n a l three dimensional electron density d i s t r i b u t i o n i s shown i n Figure 2; °-3 a l l the heavier atoms are w e l l resolved with peak d e n s i t i e s of 10 eA °-3 for carbon atoms and 30 eA for the s u l f u r atom. The f i n a l measured and calculated structure factors are l i s t e d i n Table 2; R i s 0.083 for 1176 observed r e f l e x i o n s . A f i n a l three- dimensional d i f f e r e n c e synthesis was computed and showed random f l u c t u a - °_3 tions i n electron density as great as ± 0.6eA (b) Three-dimensional difference synthesis projected along b. The hydrogen atoms have the same number as the carbon atom to which they are bonded. - 8 - Table 1 F i n a l p o s i t i o n a l ( f r a c t i o n a l , x 10 for C and S, x 10 for H) and °2 2 ° 2 thermal (A x 10 ; B i n A ) parameters, with standard deviations i n parentheses. Atom C(l) C(2) C(3) C(4) C(5) C(6) C(7) C(8) S(9) C(10) C ( l l ) C(12) C(13) -1496(11) -2755(11) -2693(12) -1380(10) 1934(10) 3393(11) 4362(10) 3905(11) 1542( 3) -0163(10) -0082( 8) 1403( 9) 2416( 9) 3036(16) 4659(17) 6565(17) 6938(14) 6997(14) 6675(15) 4800(17) 3197(15) 1674( 4) 3435(14) 5383(13) 5405(13) 3499(13) 0192(5) -0087(5) 0346(5) 1047(5) 2652(5) 3314(5) 3379(5) 2808(5) 1361(1) 0903(5) 1336(4) 2060(4) 2151(4) H(l) -160(22) 173(32) -023(11) 9(5) H(2) -381(11) 409(32) -058( 5) 2(2) H(3) -346(15) 782(23) 011( 8) 5(3) H(4) -126(11) 846(14) 127( 5) 1(2) H(5) 129(11) 823(14) 254( 5) 1(2) H(6) 353(10) 790(16) 357 ( 5) 1(2) H(7) 531(11) 454(16) 388 ( 5) 2(2) H(8) 463(15) 209(24) 275( 7) 5(3) Atom u_ u, „ II. U „ TT Mean 11 12 13 22 23 33 a(U) c(i). 5. 33 -0.49 1. 50 6.03 -0.58 3. 49 0.38 C(2) 4. 69 -0.60 0. 76 6.39 0.17 4. 06 0.40 C(3) 4. 60 0.51 1. 59 6.02 0.73 5. 01 0.40 C(4) 4. 21 0.32 1. 88 4.24 0.04 4. 69 0.33 C(5) 4. 6.3 -0.04 1. 75 4.56 -0.05 4. 01 0.33 C(6) 4. 40 -1.05 1. 38 5.15 -0.83 4. 31 0.36 C(7) 3. 87 -0.91 1. 34 6.74 0.49 4. 61 0.38 C(8) 4. 19 0.43 1. 51 5.19 0.78 4. 80 0.37 C(9) 5. 23 0.75 1. 49 4.49 -0.63 4. 84 0.09 C(10) 4. 62 0.03 1. 71 4.67 -0.14 3. 55 0.32 C ( l l ) 3. 10 0.04 1. 56 3.95 0.29 3. 72 Q.28 C(12) 3. 44 -0.58 1. 28 3.88 -0.14 3. 23 Q.28 C(13) 3. 28 0.01 1. 59 4.08 0.32 4. 26 0.31  - 10 - Table 2 Measured and calculated structure factors (Unobserved reflexions are indicated by a negative sign i n front of |F Q|). 0 - 1 C - 1 7 . t c It 14.2 - 4 , 4 0 -It) I C C 79.7" 0 16 14. 1 - L 5. 7 c -16 11.4 L 2 . « c 16 1.4 - 8 . 1 L 0 - 1 " 1 . 1 -5 .Q 0 16 - 1 . 5 - 2 . 3 0 - 16 16.4 - 1 4 . 7 c - 16 I 7.P - 1 7 . 6 c -16 - 1 . 5 -I .2 c - 16 - l . t 2.4 i - 1* - l - l 1 .> c -16 - 1 . 1 l . H 0 IS 12.5 - 5 . 7 c - Ifl i r.) -17 .7 a l" 12. C - 1 2 . 6 -11 1.4 c 1" 2. 7 c -18 11.7 4.7 0 - IB l .e c -16 - 1 •( 1.4 c -11 l a . * - I K . C c -11 12.C - 17.5 L - 1 " r l . 7 _ o , r 0 70 4 . " - 3 . 1 c -20 i .? - 0 . 1 c - 20 1.1 - 1 . C - 7 " l i . " - 1 7 . 1 -nr. •JW! i '.r " 1 . 1 -m c -/C -l.t - d . 6 s -72 0 -** 8.5 10.c c -22 *•* 4.4 0 19.* - H i . 1 1 0 I t .4 - I T . 1 0 3. 5 - 1 . 7 _ 1 c. . Irt.l . Al.l 0 5. 1 4 .4 0 1 C . » I 1.1 1 0 1 C 1 4 . ' 1 c 11 .4 - t o . * - 6 . 4 1 1 4|.£ - 1 5 . 1 5C.9 -*>5. 1 1 1 4.0 - » . H IS.9 16. 1 1 1 15. 1 - 14.5 _ 31.1 - 10.1 it - 7 0 . r 11.4 - 1 * . t •• 29. T 1.5 T . l - 2 * . 1 7.4 ;| 3:1 - 0 . ; 1 1 I C C -10 .1 1 -I - 1 - 7 . 4 1 I I C ; - 1 1 . 1 2.0 -O . t SC. 1 - 4 6 . *. 1 -} 24.C 24.4 23.7 - 2 2 . 4 1 -2 11.4 -1 7.ft 14.* 14.1 5.4. 4.6 2 i . e I*. 4. 15.5 - 1 7. 1 1 2 - 1 . 0 O.t 10. r I C S I 2 t . l - 5 . 1 n . i . 14.5 -15 .1 1 -2 - 1 . 5 - 2 . 1 7.1 - f l .C 1 • 2 - l . t 2.6 J j 5,H_ 5,5 1 " 3 *>c'.f - 4 H . 3 1 - 1 t4 .C 15.1 - 6 . 9 "> SC. 1 45. » 1 - 1 14. 1 15. 1 5 .S 1 - J - 1 . 1 1.2 _1 ' » C _ l f t . l 1 - 1 - 1 . 2 - 0 . 1 I J 11.2 11 . 1 3.2 2.6 4.4 4 .C 1 - s 5.B - 5 . 1 t . J - 4 . 4 1 - 1 15.C 14 . 1 - 1 . 7 - 8 . 1 12. r . 12.2 27.H 7 6 . 1 46. 1 47.7> 1 4 1 » . 4 3ft. 1 I. -4 12 3.7 I4y ,4 36.4 35,4 I -* 21. t 22. 1 I -t 17.4 •M. I 75. 3 - 7 5 . 1 ifl.4. 1 4 12.< - 11.1 17. 1 - 1 7 . 0 1 4 1 C 1 -10.,? I -* 15.1 14.4 ! _ W • ? _ I M - 1 . 7 2 . 1 14 .1 - I T . f t 1. "9 IH. l _ - 1 8 . 7 } . 4 14. - 12.4 5 4 . » 43 .6 1 - 5 12. 1 12.ft It.* 15.e l_ - 4 _ fl.l 1 1 . 1 -12.2 2 4 . ? - 7 1 . » 22.5 - 7 1 . 1 I*-? _ - 1 2 . ? 12.1 10.0 2 2 - l . t - 2 . 5 2 - 2 5 .4 - 5 . 6 7 7 - 1 . 1 C M 2 '2 -l.t - C P 2 1 2».t - 7 4 . 4 i i 11.1 1 4 . 0 • 0 . 7 2 1 4 U . » 3V. £, 2 - 1 7 .5 7 .1 2 3 7 C » C , 7 2 - 1 2 5 . 4 J 1 1.4 - 7 5 . 7 - 4 . 1 2 - 1 1 4 . 1 - 1 7 . 7 2 1 6 . 5 - 6 . 4 7 - 1 1 1 . * - 1 1 . 5 2 -3 7.0 7 . 1 2 - 1 I t ." It.ft 2 - 1 - U « -2.1 2 4 l . F - C . 9 ' 4 16.4 I -4 1H.3 - 1 6 . " 2 4 1 1 . 1 - 1 » .4 2 - 4 12.\ - 1 2 . 4 2 - 4 1 4 . ) - 7 0 . t j -4 5t_i_ 7 4 14.1 - 1 9 . 7 2 4 4.1 8 . 4 2 4 5 . 1 4 . 1 2 4 - 1 . 5 I - 4 5 .4 - 4 * 4 ^ 5 3 7 .J 56.o 2 - 5 11 .4 - 1 2 . 1 2 - 5 - l i e 7 .7 2 -4 ft.7 -5. 7 ? 4 7 C 1 - M l . 4 2 - 4 2 4 . 5 7 4 . 3 2 4 1 4 . 4 - 1 1 . * - 0 . 1 2 -4 LI. 2 - 1 2 . 1 l _ 4 15.9 . 1 6 . 4 2 - 4 "**•* 2 - 5 * : ! -«.? 7 6 7 1 . 9 71 .1 2 -t 11.7 U . "* Z 6 29 .4 - 7 4 . H 2 -6 22. i t 2 6 7.4 2 1 . " 2 6 l . f 2 -ft - 1 . 2 - 1 . 1 8 Hri I - t t.fl -•t.t 2 6 l ? . t 13.4 2 -ft 4. 1 - I C - J 2 6 3.4 - 2 . 4 2 - ft K . l 11 .7 2 6 - ( . 4 2 -ft 1 0 . 1 10. i _| ~\ _ _ - 2 \j> t ' - 7 i e . ? - 1 9 . 1 2 7 16.2 - 1 6 . h 7 - 7 12.C - 1 4 . 1 i 7 2 1 . 1 - 2 4 . 1 i - 7 4 C . 1 4 3 . 1 2 1 12..1 - J I V 2 - 7 32 .1 2 7 5 . 1 2 - 7 1.1 3 l.ft 2 T P .4 2 -T 5 . 7 1.2 - 5 . - J i z m i*5 -3.>4 t . t ) ,7 12.4 II.1 8.2 - l i - v a b l e 2 (Continued) ft.I t c . I 3 . " 26.7 II.I _ .6.6 „ - 2 . 4 15.5 - 1 5 . 1 - I . t 4 . 1 li.C - 2. ' _ - *j . 2 14 .3 lei 21 ,.e_ 12.) 14.2 11.2 - t? .C • 14.5 JC.2 21.2 i t . e 25.9 -4 -1.4 U.H 1 6 0 10.5 7..1 2.5 -2.4 2 fa C fa.4 -» 22-* - 2 3 . 4 1 t 0 K. 1 - 7 . 1 4.2 - 5 . 1 0 -4,4 -* 14.2 - 1 1 . 1 4 fa 0 -1.? 3. ' 4 - 1 . ( 1.2 0 ( 1 9.7 - 9 . 1 -* fa.7 \ t e a 10.1 1 6 1 12. T -17.1 ._ 2 t - 1 -I.fa •1 . 9 1 J . t 13. 1 j t 4.t -4 5.4 5.5 1 A - 1 - 1 . 7 - o . r - l . f ) 6 5.4 - 1 . 2 l . t 4 6 1 - 1 . 7 1.4 -s 1. 1 - 9 . 1 4 fa I - 1. * - l . c i.i 1..9 5 6 - 1 - 1 . 6 2.2 -5 4. 7 - * . 2 0 t 4 4.1 10.7 1 6 - 2 9. 1 7.9 -4 7.1 6.7 1 fa - 1 .* - 2 . * 5 I.J 1.6 2 t • 2 1 1.* - 4 J fc 1*9 L 5 _ - J .C -5. a 3 ft -I.I C. 1 -4 1C.1 -1 .s 8.C - 2 . * 4 fa .] -1*4 4.1 2.6 - 3 . 1 -4 -{."• -4. ' 4 fa .\ IC. 1 6 11.9 - 1C.9 o e 1 - U 4 0.4 _ - 6 p .5 9. 3 - 0 . 1 6 2. 1 - 2 . 2 i 6 9 - 1 . 4 -* 12. f 12 . - 2 fa 6 1.* l.ft ft.9 - 4 - 1 . 5 J b - j l.t 6,1. 4 - 1 - 1 . 1 - 1 - 2 . ° - l.t * 6 - J - 1 • ' - 2 . 1 -1.4 2.1 - 1 . 4 1.0 - I ." 6 ). I -3.ft CI fa 4 1 1. 1 - 9 . 5 - 6 -ft 7.1 7_ _ - L . 1. 2 t • 4 IC. 1 - *. 1 -T ~ 2.* -Ll.fr 5.C 5.4 7 l i t I IC. 1 - T ). 1 - 2 . 1 1 fa ~ 4 i . i 1.2 7 - 1 . 1 « . 1 - T IC. » -10.Ii 4 fa 4 4 . H 4.r 7 I.J - 2 . 6 4 fa -4 - 1 . J - 1 . ' -T l . t - 1. t 0 t .. 1 fc.5_ 7 - 7 -!:« - 1. 5 1.4 ! 6 "J •VI - 9 . 7 -5.1 z] uS 2 * "J ft. 1 1 - 1 . i 2 . S ) fa .$ l.\ -fa. i -M IC. 1 13.9 3 fa _. 5 - 1 •- 1.4 • 4.4 - 1 . 7 -P 1.7 2.7 5 (. -4 - 1." - 0 . 1 4.1 t. 1 -H 4. r 4. » 1 fa -ft IC. l - 1 0 . 4 e - i .* - l . h 1 fa 5.*. - p i.i 7 . 0 2 fa -fa IC. . - J . t i" 9.4 -9.<: 2 « • -1 .<. I . 1 - 12 - Results and Discussion The equations of the mean plane of the i n d i v i d u a l rings as well as the equation of the mean molecular plane are given i n Table 3. The i n d i v i d u a l f i v e - and six-membered rings are s t r i c t l y planar, but the molecule as a whole shows a small deviation from exact p l a n a r i t y . The outer atoms of the six-membered rings are displaced from the mean molecular plane (plane 1, Table 3) i n the opposite d i r e c t i o n to the atoms of the five-membered r i n g , so that the molecule i s folded very s l i g h t l y . The dihedral angles between the five-membered ring and the six-membered rings are 0.4° and 1.2°. Similar deviations from p l a n a r i t y were reported f o r dibenzoselenophene (8). The bond lengths and valency angles are l i s t e d i n Table 4 together with the corresponding bonds and angles of dibenzoselenophene (8) and carbazole (7). The distances and angles are very s i m i l a r except, of course, those in v o l v i n g unlike atoms. There are small v a r i a t i o n s i n the bond lengths i n the six-membered rin g s , C(10)-C(ll) being the longest, and C(l)-C(2) and C(3)-C(4) the shortest. These v a r i a t i o n s agree with bond order differences calculated by simple molecular o r b i t a l theory (11). The i n t e r n a l angles of the six-membered rings deviate s l i g h t l y from 120° with angles at C(l) and C ( l l ) being reduced to about 118° while the other angles are s l i g h t l y increased. The angles i n the five-membered rings of the three molecules show greater differences as a r e s u l t of the differe n c e i n angle at the hetero-atom, the angles being 91.5°, 86.6°, and 108.3°. for dibenzothiophene, dibenzo- selenophene, and carbazole r e s p e c t i v e l y . The C-S bond distance i n o o dibenzothiophene, 1.740 (a = 0.008)A i s close to the mean value of 1.72 A - 13 - Table 3 o Displacements (A) from mean planes (values underlined r e f e r to the atoms used to define the planes) 1 2 3 4 C(l) +0.016 +0.007 +0.015 +0.082 C(2) +0.001 -0.011 +0.006 +0.069 C(3) +0.009 +0.005 +0.025 +0.063 C(4) -0.004 +0.005 +0.017 +0.033 C(5) -0.007 +0.027 +0.022 -0.009 C(6) +0.028 +0.074 +0.059 +0.011 C(7) +0.012 +0.058 +0.036 -0.001 C(8) -0.010 +0.026 +0.003 -0.006 S(9) +0.001 +0.011 +0.001 +0.043 C(10) -0.003 0 +0.001 +0.045 C ( l l ) -0.019 -0.007 -0.003 +0.014 C(12) -0.015 +0.009 +0.004 +0.001 C(13) -0.014 +0.011 -0.003 +0.004 Equations of planes (X 1, Y, ; o i n A referred to a, b, c*) 1 -0.7534 X' - 0.4711 Y + 0.4587 Z' = 0.3631 2 -0.7504 X' - 0.4682 Y + 0.4666 Z' = 0.3751 ! 3 -0.7551 X' - 0.4647 Y + 0.4626 Z' = 0.3791 4 -0.7567 X' - 0.4773 Y + 0.4468 Z* = 0.2862 Angles between-plane normals (degrees) 2 3 4 1 0.5 0.4 0.8 . 2 0.4 1.3 3 1.2 - 14 - Table 4 o Bond distances (A) and angles (degrees) i n dibenzothiophene and re l a t e d molecules Dibenzothiophene o(C-•S) = o 0.008 A a(C-S-C) = 0.4° o(C- •C) = 0.011 a(S-C-C) = 0.6 CT(C-C-C) = 0.7 a(C-•H) ~ 0.1 c(C-C-H) ~ 6 Dibenzothiophene g Dibenzoselenophene Carbazo! X=S X=Se X=NH C(l)-C ( 2 ) 1.396 1.384 1.371 1.390 C(7)-C(8) 1.371 C(2)-C(3) 1.390 1.385 1.377 1.398 C(6)-C(7) 1.380 C(3)-C(4) 1.361 1.370 1.380 1.395 C(5)-C(6) 1.379 C ( 4 ) - C ( l l ) 1.391 1.392 1.395 1.400 C(5)-C(12) 1.393 C(10)-C(ll) 1.408 1.409 1.398 1.404 C(12)-C(13) 1.409 C(l)-C(10) 1.384 1.386 1.395 1.395 C(8)-C(13) 1.387 C ( l l ) - C ( 1 2 ) 1.441 1.441 1.453 1.467 C(10)-X(9) 1.734 1.740 1.899 1.414 C(13)-X(9) 1.746 C(l)-C(2)-C(3) 121.1 . 121.6 121.1 121.3 C(6)-C(7)-C(8) 122.0 C(2)-C(3)-C(4) 121.1 120.5 120.6 120.4 C(5)-C(6)-C(7) •• 119.8 C ( 3 ) - C ( 4 ) - C ( l l ) 119.5 120.0 120.3 119.5 C(12)-C(5)-C(6) 120.4 C ( 4 ) - C ( l l ) - C ( 1 0 ) 119.2 118.7 118.1 118.8 C(5)-C(12)-C(13) 118.1 - 15 - Table 4 (Continued) X=S X=Se X=NH C(l l ) - C ( 1 0 ) - C ( l ) 121.6 121.6 121.6 122.3 C(8)-C(13)-C(12) 121.5 C(10)-C(l)-C(2) 117.4 117.8 118.7 117.7 C(7)-C(8)-C(13) 118.1 C(ll)-C(10)-S(9) 112.8 112.3 112.4 108.8 C(12)-C(13)-S(9) 111.8 C(10)-C(ll)-C(12) 111.4 111.9 114.3 107.1 C(ll)-C(12)-C(13) 112.4 C(4)-C(ll)-C(12) 129.3 129.4 127.6 134.1 C(ll)-C(12)-C(5) 129.4 C(l)-C(10)-X(9) 125.6 126.2 126.0 128.9 C(8)-C(13)-X(9) 126.7 C(10)-X(9)-C(13) 91.5 91.5 86.6 108.3 Dibenzothiophene C(l)-H 1.09 H-C(l)-C(2,10) 114,128 C(2)-H 1.06 H-C(2)-C(l,3) 112,126 C(3)-H 0.99 H-C(3)-C(2,4) 120,117 C(4)-H 0.99 H-C(4)-C(3,ll) 117,122 C(5)-H 0.90 ' H-C(5)-C(6,12) 126,114 C(6)-H 0.85 H-C(6)-C(5,7) 104,135 C(7)-H 0.98 H-C(7)-C(6,8) 118,120 C(8)-K 0.95 H-C(8)-C(7,13) 126,114 - 16 - found for rela t e d conjugated h e t e r o c y c l i c molecules (12). The hydrogen atoms have been located with less p r e c i s i o n . The o C-H bond lengths range between 0.85 and 1.09 (a = 0.12) A with a mean o value of 0.97 A. The H-C-C valency angles vary from 104 to 135 (a = o 6) with a mean value of 120°. The packing of molecules i n the unit c e l l i s shown i n Figure 3. The shortest heavy-atom intermolecular distance i s a C(5)...C(11) o distance of 3.57 A. Since only C(5) c a r r i e s a hydrogen atom, there i s no s t e r i c i n t e r a c t i o n . The shortest hydrogen-hydrogen intermolecular o distance i s 2.39 A and involves the hydrogens of C(2) and C(7). Since o the van der Waal radius of hydrogen i n 1.2 A, there i s no s t e r i c s t r a i n . Figure 3. Projection of the structure along b. PART II THE DETERMINATION OF THE STRUCTURE OF DL-ORNITHINE HYDROBROMIDE - 19 - A. INTRODUCTION L-ornithine H 2N(CH 2) 3CH(NH 2)COOH i s the key amino acid of the Krebs-Henseleit, or ornithine cycle i n the mammalian l i v e r . The highly toxic ammonia produced by the deamination of amino acids i s converted into the much les s t o x i c urea by means of the ornithine cycle. Urea, the chief nitrogen end product i n mammals, i s then, eliminated v i a the kidneys. Thus, although ornit h i n e i s not a c o n s t i - tuent amino .acid of proteins, i t i s one of the more important amino acids i n protein metabolism. B. THE STRUCTURE OF DL-ORNITHINE HYDROBROMIDE Experimental DL-ornithine hydrobromide was r e c r y s t a l l i z e d from water and a small s i n g l e c r y s t a l was cut from a large c r y s t a l l i n e mass. The c r y s t a l appeared to be stable at room temperature. Unit c e l l and space group data were determined from r o t a t i o n , Weissenberg, and precession photographs. o o C r y s t a l data (X, Cu-K = 1.5418 A, X, Mo-K = 0.7107 A). — i a a DL-ornithine hydrobromide, C ^ ^ N ^ B r ; M = 213.1; m.p. 223°. 0 Monoclinic, a = 12.18 ± 0.02, b = 7.88 + 0.02, c = 11.61 ± 0.02 A, 6 = 133° 39' ± 20'. °3 U = 806.3 A , D =1.74 ( f l o a t a t i o n ) , Z = 4, D = 1.75. m x F(000) = 432. Absorption c o e f f i c i e n t for X-rays, uCCu-K^) = 72 cm \ u(Mo-K^) = 53 cm \ Absent r e f l e x i o n s : h0£ when £ i s odd, OkO when k i s odd. - 20 - 5 Space group i s P2^/c ( C 2 n ) * The i n t e n s i t i e s of the r e f l e x i o n s were estimated v i s u a l l y from Cu-K^ e q u i - i n c l i n a t i o n Weissenberg films of the h0£-h7£ layers; the layers were correlated with i n t e n s i t i e s measured from Mo-K precession a films of the hkO and hkh zones. The c r y s t a l used measured 0.25 x 0.38 x 0.50 mm and was approximately a right-angled p a r a l l e l e p i p e d . Of the possible 2171 independent r e f l e x i o n s within the copper sphere , 1559 were observed. The i n t e n s i t i e s were corrected f o r Lorentz and p o l a r i z a t i o n e f f e c t s , but not for absorption. Structure amplitudes were derived as usual. The bromide ion was located by means of a three-dimensional Patterson function (0.0458, 0.1271, 0.1875). Structure factors were calculated for a l l the three-dimensional data for bromine alone. The s c a t t e r i n g factor for Br was obtained from the curve for the uncharged bromine atom from the International Tables for X-ray Crystallography (10) by comparison with the differences i n the values of X and X (X = F, CI, I) and was corrected for anomalous dispersion according to the expression using the values Af' and Af" given i n the International Tables. The i s o t r o p i c thermal parameter, B, was taken as 4.0 A . The discrepancy factor was 0.39. A three-dimensional Fourier ser i e s was summed with Structure Analysis - 21 - phases based on the bromide ion; i n t h i s electron-density d i s t r i b u t i o n , a l l the carbon, nitrogen, and oxygen atoms were i d e n t i f i e d . These were introduced to the structure factor c a l c u l a t i o n s with s c a t t e r i n g °2 factors from the International Tables and B = 4.0 A . During the f i r s t least-squares refinement cycle R dropped to 0.27. A second Fourier synthesis gave well-resolved peaks f o r each of the ten heavy atoms. Further refinement of the p o s i t i o n a l and i s o t r o p i c thermal parameters, together with an o v e r a l l scale factor proceeded by the block-diagonal least-squares method, the function minimized being 2 Zw(j F |—|F |) . As the structure factors are least accurate for the very strong r e f l e x i o n s which are d i f f i c u l t to estimate v i s u a l l y , the weighting scheme employed was = 1 for |F Q|<F' and = F /|F | I I * ' ' * for |Fo|>F , where F was taken as 9. After four cycles of i s o t r o p i c least-squares refinement, R was 0.20. At t h i s point the i n t e n s i t i e s of a few re f l e x i o n s with very marked |F |-|F | differences were re- estimated v i s u a l l y . A f t e r an a d d i t i o n a l s i x cycles of isotropic,, refinement, R was 0.15 and the parameter s h i f t s were small i n magnitude and random i n d i r e c t i o n . Subsequent anisotropic cycles of refinement reduced R to 0.14. At that point the thirtee n hydrogen atoms of the molecule were located by means of a difference synthesis. The hydrogen atoms are °-3 moderately well-resolved with peak den s i t i e s of 0.7-1.3 eA . The hydrogen atoms were introduced into the structure f a c t o r c a l c u l a t i o n s °2 with scattering factors from the International Tables and B = 4.0 A . During the f i n a l three cycles of least-squares refinement, the thermal parameters of the hydrogen atoms were refined i s o t r o p i c a l l y while those of the heavier atoms were re f i n e d a n i s o t r o p i c a l l y . A l l the parameter s h i f t s were small and nonsystematic; the larges t parameter s h i f t during the l a s t cycle being one-third of a standard deviation for the non-hydrogen atoms and three quarters of a standard deviation for hydrogen atoms. The f i n a l observed and calculated structure factors are l i s t e d , i n Table 5; R i s 0.13 for the 1559 observed r e f l e x i o n s . The f i n a l three- dimensional Fourier synthesis i s shown i n Figure 4. The atoms are °-3 well resolved with peak d e n s i t i e s of 70 eA for the bromide ion, ° ~* 3 °™3 °~3 16 eA for oxygen atoms, 12 eA for nitrogen atoms, and 10 eA for carbon atoms. These high peak densities may be the r e s u l t of high absorption. The f i n a l three-dimensional diff e r e n c e synthesis revealed random fl u c t u a t i o n s i n electron density d i s t r i b u t i o n as great as 1 1 eA . However, i n the v i c i n i t y of the bromide ion there i s a 3 eA , °-3 peak flanked on two sides by troughs at 2 eA and on each of the : °-3 remaining opposing sides by a peak of 1 eA The f i n a l p o s i t i o n a l and thermal parameters of the non-hydrogen atoms are i n Table 6. The bond lengths and valency angles are i n Table 7. The p o s i t i o n a l parameters of the hydrogen atoms which have been determined with much less accuracy are l i s t e d i n Table 8, together with a summary, of the molecular dimensions involving hydrogen atoms. Results and Discussion Due to the presence of a centre of symmetry, the unit c e l l contains two of each of. the o p t i c a l isomers of ornithine hydrobromide. The standard molecule i n t h i s analysis happens to be the D-isomer. The - 2 3 - Table 5 Measured and calculated structure factors (Unobserved r e f l e x i o n s are indicated by a minus sign i n front of J F | ) . h k 1 •ii Ii ;• iiii iii i i iii iiii :jj j i ii;! |j ; i iii iii \ fi i ;' : -\t ii ii iii ii i i 1 '»il_ 1.0 i 1 | j | i * i «ii •»! i ! j j i * - j j i i 1 0 - -ft) |-i iii ii.i if" !" :j i i.t . i i i [ t (»i» 11 !! It!' 'i ji'i '\'\ j ti i t V 1 .J v :| i iii ii !:» 1: i 'i> J>i. i iii; ;!.;.: :i! ii iiii -iii :;; ; i;i .i;i il i 1 1 ' " :i iii; Ii \ i ii; 2ii 1 E |i i >.l 77* ;• i iiii ~K TW a jjlt i 1—a—•!:; t »ii :j | 'iii: 'ii:: •i \ i 'ii i:i 1 •ii iiii 1 ! loit i * ~-W.\ i i "ii i J ! J ; i - 1 fill II.I i \ jp |i ii iii; 1'. • i i iii jjii M i l i -*_ _ _Jll|_ ill* ;• i iii i.i-1. t *'•> :;; * io!» lo'.b \ ii;i :i;i Ii if i | iiii •ii :i j iii •mi i 'iii 1 -t j 1S»1_ Ii i i :l ->.'< i t'a w ii i \ iiit iiii J i "'• iilii ij ;i:; 'ii: -• ;i ii -J_ _ . L It i j I; ii iii \ si; rS 1 Iii ii: ;< - 1— -I. |;i -ii iii ;jii ill'. \ j ijjj |: • n. - l i s -iii 1 • j j i i |*io i i r ;.i iii iiii i i • \a -j ii; «:] .J M ; i i ' ; •. :i; i iiii n'.l M'.l -ij :i [ iiii iiii j :* :; ; iiii ii; -! I 3 iiii iiii ; 1? 0 iiii iii;! :i:I •! i ii: ":* I S3 "B: .-; — j'ii M . . ° i & is!; ;| .j : i I'i I ; I tie ij i £ "i -\'.' '!;* : L 4l!« •I • il'i H'» i iii' -Jii' i ;ii iii' iii iii 1 i ii iii :| !;" :J 1..4 -11.' i i Ii l t i( " i - io i u!»_ j j i i 3— i iiii ;|i i i ii ;i \ i is i l : i I -i't -j'.t "J ii;! 1 j j • ^ i l 'r'ii :| III:! : ' : ! . i*:p -I.N iii I § :!jii 1 ,:i; si; ii ,1 iii -Ii:' i •i; s • i . J».o 11.' "If"ii • j « i j _-t la iV.o J.ii ;'i iii iii -10 ! iil^l: l w Ii 1 j iii i i i •I «: i i o i ! I": - J L. Iii) :J :* I I «I i iiii iiiii :ii 1i| iii 1 i Ii 1 :|! ii H; iiii :i *: • I -l -ii.'i iii ii iiii iii :; iii iiiii ii '; iii; iiii j i !jij |j iiii iiii. -a. " r l ! - i l l ii iii* ill's :| i't ' ' ' 4 ;i i j  ;i;i :i;i .* .si; iii iii % 11 a! :1i —i»tf~ nii S ! (t i l 4- i ii i i -10 ; Ii 1 • 1 ;i 1 j 1 ii - 1 i if"!" i !_ Ijij.. | 4- :', 'iiihiii ;i i iii Iii :i 1 1 iiii ;j -j I:! "it III* - •i .', I II 'N i'i' 1 t i l -l.t -!' 1 •' -11 \ Hi: iiiii il i iii |i 1 1 | 1 iii - i l i fi:! a J , i . • • -i _ _ 1 I j jl« i o 4 A Figure 4(a). Sections of the f i n a l electron-density d i s t r i b u t i o n p a r a l l e l to °-3 (010). Contours at i n t e r v a l s of 2 eA , exceDt at Br where °-3 contours are at i n t e r v a l s of 10 eA (b). A perspective drawing of the molecule as viewed along the b-axis, showing atom numbering used. - 25 - f i n a l three-dimensional electron density d i s t r i b u t i o n i s shown i n Figure 4 together with a drawing of the molecule giving the atom numbering used i n t h i s analysis. The compound i s a zwitterion, -+ + - Br NH 3(CH 2) 3CH(NH 3)COO , with both nitrogens accepting protons to form tetrahedral C-NH 3 + groups. The molecule i s composed of two approximately planar groupings of atoms, a carboxyl group and an a l i p h a t i c side chain terminating i n nitrogen atoms. The equation of the mean plane through 0(1), 0(2), C ( l ) , C(2) i s -0.3206 X' + 0.9459 Y - 0.0501 Z' = 1.2152 O where X', Y, Z' are coordinates i n A with reference to orthogonal axes a, b, and c*. The deviations of the atoms from the plane are: o o o o 0(1), +0.005 A; 0(2), +0.005 A; C ( l ) , -0.014 A; and C(2), +0.003 A. o The a-nitrogen atom, N ( l ) , l i e s 0.823 A out of the plane as compared o o to a value of 0.436 A for L-glycine (13), 0.446 A f o r L - l y s i n e o hydrochloride dihydrate (14) and 0.838 A for L-ornithine hydrochloride (15). The a l i p h a t i c side-chain i s f u l l y extended; i t s mean plane has the equation: 0.8133 X' + 0.4790 Y - 0.3302 Z' = 2.5741 o o The deviations from the plane are N ( l ) , -0.074 A; C(2), +0.086 A; b o o o C(3), +0.069 A; C(4), -0.116 A; C(5), -0.029 A; and N(2), +0.050 A. o C(l) i s displaced +1.399 A. The dihedral angle between the two planes i s 77.9° a  compared to 78 7° f o r ornithine hydrochloride (15) and 71.4° for l y s i n e (14). The two C-0 distances are qual within experimental error, the mean value be g 1.249 A. Table 6 4 ° 2 2 F i n a l p o s i t i o n a l ( f r a c t i o n a l x 10 ) and thermal (A x 10 ) parameters, with standard deviations i n parentheses Atom X y z C(l) 4628(15) 3446(22) 2064(16) C(2) 3243(12) 2833(22) 1749(15) C(3) 2284(13) 4375(23) 1371(14) C(4) 3073(14) 5464(26) 2857(15) C(5) 2141(13) 7068(23) 2421(14) N(l) 2316(13) 1615(21) 0435(15) N(2) 3032(12) 8259(22) 3772(13) 0(1) 5823(11) 3692(15) 3481(13) 0(2) 4434(11) 3710(16) 0873(12) Br 0447(1) 1279(2) 1891(2) Atom U-,., U, ̂  11 12 13 22 23 33 C(l) 2.56 0.55 1.75 2.98 0.27 3.33 C(2) 2.20 -0.16 1.98 2.77 0.01 3.72 C(3) '2.37 -0.41 1.92 3.18 -0.51 3.23 C(4) 3.41 0.35 2.32 4.48 -0.47 3.36 C(5) 2.80 0.06 1.94 3.08 -0. 32 2.90 N(l) 3.32 -0.06 2.31 2.90 -0.05 4.31 N(2) 2.96 -0.11 2.05 4.16 -0.58 3.36 0(1) 2.45 -0.25 2.18 4.00 0.27 4.37 0(2) 4.11 0.09 3.25 5.06 0.81 4.19 Br 3.20 -0.10 2.22 3.85 -0.09 3.66 Mean a: C,N,0 0.35 0.44 0.23 0.85 0.44 0.35 Br 0.05 0.04 0.04 0.14 0.05 0.06 - 27 - Table 7 o o Bond distances (A) and angles (degrees) (a = 0.02 A and 1.5°) C(l)-C(2) 1.537 C(l)-C(2)-C(3) 108.3 C(2)-C(3) 1.525 C(2)-C(3)-C(4) 111.2 C(3)-C(4) 1.532 C(3)-C(4)-C(5) 110.1 C(4)-C(5) 1.533 Mean C-C-C 109.9 Mean C-C 1.532 C(l)-C(2)-N(l) 112.6 C(2)-N(l) 1.465 C(3)-C(2)-N(l) 109.6 C(5)-N(2) 1.473 C(4)-C(5)-N(2) 109.9 Mean C-N 1.469 Mean C-C-N 110.7 C(l)-0(1) 1.249 C(2)-C(l)-0(1) 116.8 C(l)-0(2) 1.248 C(2)-C(l)-0(2) 116.9 Mean C-0 1.249 Mean C-C-0 116.9 0 ( l ) - C ( l ) - 0 ( 2 ) 126.2 - 28 - Table 8 Hydrogen atoms 3 ° P o s i t i o n a l parameters ( f r a c t i o n x 10 ; a ^ 0.25 A; the mean B being o 2 o o 1.3 A ), bond lengths (A, a ^ 0.25 A), and valency angles (degrees, a ^ 15 - 20°) Atom Bonded to x y z H(l) N(l) 269 077 049 H(2) N(l) 185 205 -055 H(3) N(l) 157 098 013 H(4) N(2) 393 832 411 H(5) N(2) 360 762 494 H(6) N(2) 260 903 369 H(7) C(2) 358 250 284 H(8) C(3) 217 517 031 H(9) C(3) 123 398 093 H(10) C(4) 470 563 381 H ( l l ) C(4) 283 493 374 H(12) C(5) 192 752 152 H(13) C(5) 155 725 256 N-H 0.8-1.1, mean 0.9 C-H 0.9-1.4, mean 1.1 C-N-H 107-130, mean 117 H-N-H 86-124, mean 101 C-C-H, 78-127, mean 108 N-C-H H-C-H 111-120, mean 114 - 29 - Table 9 Carbon-oxygen bond lengths i n some amino acids Amino Acid C(l)-0(1) C(l)-0(2) Mean DL-ornithine hydrobromide 1.249 A O 1.248 A 1.249 A L-ornithine hydrochloride 1.257 1.245 1.251 L - l y s i n e hydrochloride dihydrate 1.250 1.246 1.248 L-alanine 1.247 1.256 1.253 As shown i n Table 9, these values agree well with the corresponding internuclear distances of other amino acids. The two C-NĤ "*" bonds also are equal within experimental error (Table 7); the average value o o of 1.469 A i s s i m i l a r to that of 1.482 A for L - l y s i n e (14), and that o of 1.492 A for ornithine hydrochloride (15), these differences probably not being s i g n i f i c a n t . The C-C bond lengths do not d i f f e r s i g n i f i c a n t l y from each other (Table 7). The mean C-C distance of 1.532 A agrees, well with the sing l e bond length of 1.533 proposed by B a r t e l l (16) on the basis of electron d i f f r a c t i o n studies of normal hydrocarbons butane through heptane. The mean C-C distance i s s i m i l a r to the '.' o ; o analogous values of 1.524 A for l y s i n e (14), 1.525 A for L-alanine (17), o and 1.530 A for ornithine hydrochloride (15). The bond angles of the carboxylate group are equal within the l i m i t s of experimental error to the analogous'angles i n l y s i n e (14), and ornith i n e (15). - 30 - Table 10 Carboxylate bond angles i n ornithine and l y s i n e d e r i v a t i v e s Angle Compound Ornithine HBr Ornithine HC1 Lysine HC1-2H20 0( l ) - C ( l ) - 0 ( 2 ) 126.2° 126.6° 125.5° C(2)-C(l)-0(1) 116.8 116.0 116.8 C(2)-C(l)-0(2) 116.9 117.0 117.7 S i m i l a r l y , the C-C -N angles of the above compounds resemble one another; however, the agreement i s not so good as i n the case of the carboxylate group angles. Table 11 Carbon-carbon-nitrogen angles i n ornithine and l y s i n e d e r ivatives Angle Compound Ornithine HBr Ornithine HC1 Lysine HC1-2H20 C(l)-C(2)-N(l) 112.6° 110.3° 109.7° C(3)-C(2)-N(l) • 109.6 107.8 111.8 C(4)-C(5)-N(2). 109.9 110.4 C(5)-C(6)-N(2). ; 110.9 The C-C-C angles of the three amino acids are s i m i l a r and close to the tetrahedral value of 109.5, - 31 - Table 12 Carbon-carbon-carbon angles i n o r n i t h i n e and l y s i n e d e r ivatives Angle Ornithine HBr Compound Ornithine HC1 Lysine HC1-2H20 C(l)-C(2)-C(3) 108.3° 110.2° 109.8° C(2)-C(3)-C(4) 111.2 112.4 114.6 C(3)-C(4)-C(5) 110.1 109.0 110.0 C(4)-C(5)-C(6) 111.5 The v i s u a l data are not s u f f i c i e n t l y accurate to y i e l d r e l i a b l e values for the hydrogen parameters. The average N-H bond length of o o o 0.89 A i s close to the value of 0.94 A for l y s i n e (14), and 0.95 A for ornithine hydrochloride (15). On the other hand, a l l these bonds o are somewhat shorter than the standard N-H bond distance of 1.03 A o for the ammonium ion and that of 1.01 A for ammonia. However, these differences are not s i g n i f i c a n t . o The mean C-H bond length of 1.14 A i s i n s i g n i f i c a n t l y longer o than the analogous mean values of 1.06 and 1.05 A for l y s i n e (14) and ornithine (15) r e s p e c t i v e l y . A p r o j e c t i o n of the structure i s shown i n Figure 5. The most s i g n i f i c a n t feature of the packing i s a system of three N-H...0 and three N-H...Br hydrogen bonds involving a l l s i x active hydrogen atoms. The terminal nitrogen atom, N(2), donates three protons, one to the bromide ion of the standard molecule at [010], another to the carboxylate 0(2) of the nearest screw-axis-generated molecule at [111] and the l a s t gure 5. Projection of the structure along b; broken l i n e s are hydrogen bonds. - 33 - proton to the carboxylate 0(1) of the adjacent center-of-symmetry- generated molecule at [111], The side-chain nitrogen atom, N ( l ) , also donates three protons, one to the carboxylate 0(1) of the closest screw-axis-generated molecule at [101] and the remainder to nearby bromide ions. The hydrogen bond distances and angles are i n Table 13. One of the C-N...Br angles i s 155°, but the other C-N...0,Br angles are a l l i n the range 95-109°. The positions of the hydrogen atoms support the hydrogen bond assignments; the H...0 distances are about o o 2.0 A, the H...Br distances 2.6 A, and the bonds a l l show the i usual deviations from exact l i n e a r i t y , the H-N...0, Br angles varying from 7° to 25°. There i s one further short N(2)...0(2) internuclear o contact of 2.97 A, but the C-N...0 angle i s 166° and there i s no o intervening hydrogen atom, the shortest H...0 distance being 2.6 A, so that t h i s contact does not represent a hydrogen bond. The N-H...0 distances (2.84, 2.84, 2.89 A) and the N-H...Br distances (3.29, 3.36, o 3.46 A) are close to the values usually found i n these types of systems (18). The bromide ion acts as an acceptor for three hydrogen bonds, the N...Br ...N angles being 91, 91, and 139°. 0(1) accepts two protons, the C-0...N angles being 124° and 127°, and the N...0...N angle 108°. . 0(2) accepts one hydrogen bond, and the C-0...N angle i s 118°. The above system of hydrogen bonds i s complex i n that the f i v e heavier atoms of the standard molecule p a r t i c i p a t e i n twelve hydrogen bonds which involve the corresponding atoms [N(l), N(2), 0(1), 0(2), Br] i n twelve d i f f e r e n t molecules. The structure of DL-ornithine hydrobromide i s s i m i l a r to that of L-ornithine hydrochloride. Layers of L-ornithine molecules p a r a l l e l - 34 - to the ab plane are almost i d e n t i c a l i n the structures. In L-ornithine o hydrochloride these layers are stacked along c, giving a c-axis of 5 A; i n DL-ornithine hydrobromide, the layers of L-ornithine molecules are related by the c g l i d e plane to layers of D-molecules (Figure 5) r e s u l t i n g i n a c-axis of about double the length. - 35 - Table 13 o Distances (A) and angles (degrees) i n the hydrogen bonds, N-H...A (A = 0 or Br) Bond C-N...A N( l ) - H ( l ) . . . 0 ( 1 ) , IV[101] N(l)-H(2)...Br, II[001] N(l)-H(3)...Br, III[000] 2.84 3.46 3.36 105 109 155 N(2)-H(4)...0(2), IV[111] N(2)-H(5)...0(1), III[111] N(2)-H(6)...Br, I[010] 2.84 2.89 3.29 99 106 95 Equivalent pos i t i o n s are I x II x III -x IV -x - y -y + y + z -z together with t r a n s l a t i o n i n a, b, and c indicated i n square brackets. PART III THE DETERMINATION OF THE STRUCTURE OF HISTAMINE DIPHOSPHATE MONOHYDRATE - 37 - A. INTRODUCTION Histamine, one of the most important autacoids i n the human body, i s synthesized i n vivo by the enzymatic decarboxylation of h i s t i d i n e . Almost a l l mammalian tissues contain histamine and are capable of synthes ing i t . The histamine which i s released by injured body tissues gives r i s e to many of the signs and symptoms of trauma and a l l e r g y . B. THE STRUCTURE OF HISTAMINE DIPHOSPHATE MONOHYDRATE Experimental Histamine diphosphate was r e c r y s t a l l i z e d from water. The resultant c o l o r l e s s , transparent, needle-shaped c r y s t a l s are elongated along a and appear to be stable i n room a i r ; no r a d i a t i o n damage was observed. The unit c e l l parameters and space group were determined from various r o t a t i o n , Weissenberg and precession f i l m s . The melting point could not be determined as the c r y s t a l began to lose water of hydration at 88° and became completely l i q u i d at 118°C. o C r y s t a l data (A, Mo-K = 0.7107 A). — a 4-(2-aminoethyl)-imidazole diphosphate monohydrate, C<.H.j^N30gP2; M = 325.2.-; O Monoclinic, a =.7.99 + 0.01, b = 13.17 ± 0.01, c = 13.19 ± 0.01 A, 3 = 111.2 ± 0.1°. °3 ; :' U = 1294 A , D. = 1.669 ( f l o a t a t i o n ) , Z =4, D = 1.668. m x F(000) = 680 . Absorption c o e f f i c i e n t for X-rays, u(Mo-K ) = 3.90 cm \ a Absent r e f l e x i o n s : hOfc when % i s odd, OkO when k i s odd. Space group P2^/c ( C ^ ) . The i n t e n s i t i e s of a l l r e f l e x i o n s with 26(Mo-K ) less than 46° a - 38 - were measured on a G.E. XRD-5 Spectrogoniometer, with Single C r y s t a l Orienter, using a s c i n t i l l a t i o n counter, Mo-K^ r a d i a t i o n (zirconium f i l t e r and pulse height analyzer), and the moving-crystal moving- counter technique (9). The corresponding minimum interplanar spacing o i s 0.91 A. A l l the i n t e n s i t i e s were corrected for background and the structure amplitudes were derived as usual. The c r y s t a l , measuring 0.5 x0.5 x 2.0 mm, was mounted with a* p a r a l l e l to the goniostat axis. Possible errors i n the measured structure factors were examined. Considering the c r y s t a l as a cylinder of mean diameter 0.5 mm, uR i s 0.0975 and hence the absorption correc- t i o n factor A i s 1.10 and constant i n the range 9 = 0-40°; therefore, the error due to absorption i s n e g l i g i b l e . In addition, absorption errors due to non-uniformity of c r y s t a l dimension were estimated by considering the longest and shortest path lengths i n the cross-section of the c r y s t a l . The absorption corrections for the corresponding structure factors are exp (3.9 x 0.07/2) and exp (3.9 x 0.05/2), that i s 1.15 and 1.10 re s p e c t i v e l y . Thus the maximum deviation from the mean cor r e c t i o n of 1.125 i s 0.025 or 2.2%. Since the cumulative possible maximum error i n F due to absorption i s less than 2.3% and since the o majority of errors w i l l be much smaller than t h i s value, no correction o was made for absorption. 1747 refle x i o n s i n the range 0 < 26 < 46 were observed; 1554 (89%) had i n t e n s i t i e s above background. Structure Analysis The positions of the two phosphorus atoms were determined from a three-dimensional Patterson synthesis ( P - l , 0.333, 0.125, 0.370; P-2, 0.740, 0.290,.0.216) and structure factors were calculated for a l l the 39 - three-dimensional data for phosphorus only using s c a t t e r i n g factors from the International Tables for X-ray Crystallography, 1962 (10) °2 and i s o t r o p i c thermal parameters of 4.0 A . The discrepancy factor, R, was 0.57 for the observed r e f l e x i o n s . A three-dimensional Fourier synthesis with the phase angles based on the phosphorus atoms revealed the p o s i t i o n s of a l l the non-hydrogen atoms. When these were introduced into the structure factor c a l c u l a t i o n s with s c a t t e r i n g factors from the °2 International Tables and B = 4.0 A , R dropped to 0.32. Subsequent refinement of the p o s i t i o n a l and i s o t r o p i c thermal parameters together with an o v e r a l l scale f a c t o r , was c a r r i e d out by means of the block- diagonal least-squares method, the function minimized being 2 Ew(|F |-|F I) . Since the structure factors were considered to be 1 o 1 1 c ' least accurately measured for the strong r e f l e x i o n s which are most affected by absorption as well as for the weak re f l e x i o n s whose i n t e n s i t i e s are s i m i l a r to that of background r a d i a t i o n , the following weighting scheme was employed: r •• 1 where F* = 16 and G* = 26. This scheme gives = 0.80 f o r |F | =1, maximum î w = 1 f o r | F Q | = 16 and thereafter decreasing weights so that at |F | =42, for example, •w = 0.71. Unobserved r e f l e x i o n s were assigned •w = 0.29. After seven i s o t r o p i c least-squares refinement cycles, R was 0.12; shifts i n p o s i t i o n a l parameters were about one-third of a standard deviation while - 40 - thermal parameter s h i f t s were of the order of one standard deviation. The parameter s h i f t s of the water oxygen atom, however, were larger. Therefore, i t s p o s i t i o n was redetermined on an a d d i t i o n a l d i f f e r e n c e synthesis. Six anisotropic refinement cycles reduced R to 0.09. Thereafter, a d i f f e r e n c e synthesis was summed and a l l 17 hydrogen atoms (with peak °-3 values of 0.5-0.7 eA ) were located (Figure 6). The hydrogen atoms were included i n subsequent structure factor c a l c u l a t i o n s with °2 s c a t t e r i n g factors from the International Tables and B = 4.0 A . Aft e r s i x refinement cycles i n which the thermal parameters of the heavy atoms were refined a n i s o t r o p i c a l l y while those of the hydrogens were refined i s o t r o p i c a l l y , R was 0.07. However, as the temperature factors of the water hydrogens were too high at t h i s point, t h e i r p o s i t i o n s were redetermined on a di f f e r e n c e synthesis. At the completion of the f i n a l series of eight least-squares refinements, the p o s i t i o n a l parameter s h i f t s were small and nonsystematic, the largest s h i f t being one-sixth of a standard deviation f o r the heavy atoms and one-third of a standard deviation f o r the hydrogen atoms. The p o s i t i o n a l and anisotropic thermal parameters of the heavier atoms from t h e . f i n a l least-squares cycle are given i n Table 14, together with t h e i r standard deviations computed from the inverses of the diagonal terms of the matrix of the least-squares normal equations. Also l i s t e d i n Table 14 are the hydrogen atom p o s i t i o n a l and i s o t r o p i c thermal parameters together with t h e i r standard deviations. The f i n a l e l e c t r o n - density d i s t r i b u t i o n i s shown i n Figure 7, the atom numbering used i n Figure 8.  - 42 - Table 14 F i n a l p o s i t i o n a l parameters ( f r a c t i o n a l , x 10^ for P, 0, N, and C; 3 0 2 2 0 2 x 10 for H) and thermal parameters (U.. i n A x 10 ; B i n A ), with p 2 t h e i r standard deviations i n parentheses [a(B) for hydrogen=3-4 A ]. Atom x v z B P( l ) 3466(4) 1287(2) 3749(2) P(2) 7489(4) 2879(2) 2299(2) 0(3) 1917(11) 1800(7) 2789(6) 0(4) 2743(11) 0259(7) 4005(6) 0(5) 3879(11) 1925(7) 4759(6) 0(6) 4989(11) 1139(7) 3351(7) 0(7) 5669(11) 2715(7) 2463(7) 0(8) 7098(11) 2715(7) 1062(7) 0(9) 8026(12) 3965(7) 2565(7) 0(10) 8852(11) 2118(7) 2915(7) N ( l l ) 2734(14) 4402(9) 1352(8) C(12) 1971(17) 4447(12) 2232(10) C(13) 3389(19) 4695(12) 3299(11) C(14) 2775(16) 4695(10) 4246(10) 0(15) .: 2361(17) 5467(10) 4782(10) N(16) 2046(14) 5058(8) 5662(8) 0(17) '2231(16) 4070(10) 5648(9) N(18) 2659(14) 3819(8) 4790(8) 0(w,19) ' 9536(15) 1440(13) 4990(9) H(20) 363(23) 379(13) 166(13) 3.8 H(21) 187(17) 433(10) 065(10) 1.3 H(22) 323(22) 504(13) 121(13) 3.7 H(23) 117(18) 375(11) 226(11) 1.5 H(24) 099(18) 500(11) 208(11) 1.7 H(25) 424(17) 407(11) 338(10) 1.3 H(26) 394(19) 540(11) 319(11) 2.3 H(27) 234(13) 624(8) 461(8) 1.0 H(28) 204(18) 542(11) 628(11) 2.0 H(29) 196(13) 355(8) 615(8) 1.0 H(30) 295(18) 315(11) 469(11) 1.7 H(31) 894(25) 167(15) 430(15) 5.5 H(32) 870(25) 160(15) 540(15) 5.5 H(33) 084(22) 192(13) 296(13) 3.7 H(34) , 561(22) 212(13) 283(13) 3.7 H(35) 612(21) 278(13) 076(13) 3.2 H(36) "• 753(24) 485(14) 151(14) 4.7 - 43 - Table 14 (Continued) Atom U l l U12 U13 U22 U23 U33 P ( D 2. 53(12) 0.06(12) 1. 43(9) 2. 69(16) -0. 06(12) 2. 80(12) P(2) 2. 78(13) 0.64(12) 1. 43(10) 2. 43(15) 0. 43(12) 3. 10(13) 0(3) 3. 36(38) 1.17(40) 1. 50(28) 5. 57(55) 0. 64(39) 2. 87(36) 0(4) 4. 55(40) -1.11(39) 2. 22(29) 3. 61(47) -0. 36(37) 3.62(37) 0(5) 3. 53(40) 0.20(37) 1. 31(30) 3. 50(46) -0.91(37) 3. 49(38) 0(6) 3. 38(37) 0.39(36) 2. 08(29) 3. 45(47) 0.40(38) 4. 40(40) 0(7) 4. 56(40) 1.72(41) 3. 54(32) 4. 78(54) 2. 18(44) 6. 57(47) 0(8) 3. 39(40) 0.55(38) 1. 19(31) 4. 05(48) -0. 76(39) 3. 59(40) 0(9) 6. 24(51) 0.05(42) 2. 07(35) 3. 07(47) 0. 05(39) 3. 78(41) 0(10) 3.45(40) 0.62(40) 1. 58(31) 4. 43(51) 1. 21(41) 4. 16(41) N ( l l ) 4. 74(53) -0.18(51) 2. 26(37) 4. 47(65) -0. 60(48) 3. 63(47) C(12) 3. 77(62) 0.12(62) 1. 48(45) 5. 43(84) 0. 26(61) 3. 26(57) C(13) 4. 64(64) -0.47(67) 2. 09(46) 5.63(87) 0. 39(65) 3. 95(60) C(14) 3. 13(56) -0.15(55) 1. 39(43) 4. 03(72) 0. 36(56) 3. 48(57) C(15) 3. 91(58) -0.09(55) 1. 68(44) 3. 34(67) 0. 22(55) 3. 66(57) N(16) 4. 25(51) 0.19(47) 1. 61(36) 3. 62(58) -0. 37(44) 2. 99(45) C(17) 3. 55(57) 0.20(54) 1. 28(42) 3. 62(67) 1. 09(52) 2. 78(51) N(18) 4. 60(54) 0.02(47) 1. 86(40) 2. 78(54) -0. 36(46) 4. 05(51) 0(19) 7. 66(60) 7.99(69) 4. 36(45) 18. 55(121) 6. 73(70) 7. 02(58) - 44 - Figure 8. Drawing of the structure viewed along a and showing the atom numbering used. - 46 - The f i n a l measured and calculated structure factors are given i n Table 15; R i s 0.072 for 1554 independent observed r e f l e x i o n s . A f i n a l three-dimensional diffe r e n c e synthesis was computed and showed °-3 random fl u c t u a t i o n s as high as ± 0.6 eA , Results and Discussion The structure contains a histamine cation, two H„P0, anions and 2 4 a molecule of water. The imidazole r i n g of histamine appears to be planar within the l i m i t s of experimental erro r . The equation of the mean plane i s 0.8206 X' + 0.0908 Y + 0.5642 Z' = 3.659 O where X f, Y, and Z' are coordinates i n A referred to the orthogonal axes a, b, and c . The deviations of the atoms from the mean plane are: C(14), +0.009 A; C(15), -0.008 A; N(16), +0.004 A; C(17), +0.002 A; and N(18), 0 -0,007 A, The deviations of the corresponding hydrogen atoms from the o o plane of the imidazole r i n g are: H(27), +0.02 A; H(28), +0.23 A; H(29), o o -0.08 A; and H(30), +0.08 A. Thus the hydrogens l i e i n the plane of the h e t e r o c y c l i c ring within the l i m i t s of accuracy of the method. The deviations of the side chain atoms from the imidazole plane are: C(13), o o o +0.12 A; C(12), -1.16 A; and N ( l l ) , -0.93 A; a l l highly s i g n i f i c a n t displacements. The ethylamine side chain i s approximately planar; the equation of the mean plane through N ( l l ) , C(12), C(13), C(14) being: -0.1541 X1 + 0.9743 Y - 0.1643 Z' = 5.159 O with deviations of +0.021, -0.018, -0.024, and +0.021 A res p e c t i v e l y . The dihedral angle between the plane of the rin g and the plane of the side, chain i s 82.5°. However, the plane of the chain does not b i s e c t the r i n g , instead i t i s rotated toward N(18) so that - 47 - Table 15 Measured and calculated structure factors (Unobserved r e f l e x i o n s are indicated by a negative sign i n front of JF j ) . k l / F D / F C h=0 0 2 5B.2 - 5 1 , 9 0 4 6 7.6 62.lt 8 I 37.7 - 3 8 . 1 8 3 28.0 20.1 7 -11 4.1 2 7 11 1 1 . a -14 a 8 0 5 -11 1 5 . 0 15.4 11 17.7 15.9 4 - 8 4 . 7 2.1 4 8 14 . 9 16.7 4 4 37.6 37 4 - 5 9.9 a 4 7 5.4 -5 4 -7 10.4 12 4 <i -'l.l 0 1 2 T T 0 7 0 2 8 24 2 -10 15 2 10 12 2 -12 32 .8 - 2 .8 -15 . 4 12 .2 J2 .0 . 9 .8 .5 It / 45.4 46.5 8 9 2 2 . 4 -22.b 8 11 6.6 -7.1 9 2 37.5 37.0 9 4 10.5 10.2 B -2 - t . 7 -5 tt 2 4 7 . 9 50 2 43.7 44.0 -2 22 - 6 2 0 - 4 4 16.6 -19 .1 -4 9.3 9.2 6 B . l T.7 4 10 9 . 6 10.1 4 -12 U . O - 1 2 . a 5 -1 7.5 10.0 5 1 33.2 30 . 4 5 -3 - 1 . 5 1 . 8 8 -4 2 J . 5 22 B 4 17.0 16 8 -6 39.J 42 8 b 1 2 . 2 - 3 J 8 -8 13.6 -12 8 B 6.9 - 6 3 5 5 3 1 4 - 9 5.7 b 4 -11 7 . 8 -7 4 11 5 . 4 2 4 -13 14.6 - 8 5 0 31.1 -30 5 2 6.5 8 3 -1 4 U 3 I 10 J -3 48 3 J 42 3 - 5 4 . 7 49 . 4 - 9 .2 -45 . J 40 .2 0 . 9 .6 .2 .0 0 6 50.3 -47 .9 0 8 62.J 6 3 . 1 0 10 - 2 . 0 - 2 . 9 0 12 - 2 . 3 - 7 . 2 t I 17 . 9 -11.7 1 3 96.2 35.8 9 6 23.3 -24 .0 9 8 16.0 - 6 . 9 9 10 6.5 10 9 7.5 - J . 6 10 1 10.1 1.7 10 1 31.2 - 3 1 . 1 - 6 37.1 3B.Y 7 8 -2 .1 0 . 1 - 6 4.5 - 2 . 0 -10 6 . 0 - 3 . 4 10 7.3 - 6 . 5 7 -12 - 2 . 4 - 4 . t 5 3 3B . 0 - J 7 . 5 5 - 5 8.7 - 7 . 8 5 5 44 ,4 43 .9 5 - 7 25.2 - 2 6 . 5 5 7 12.2 -13 .3 5 - 9 24.6 2 4 . 6 8 -10 12.9 - U a io 10.7 IT 9 -I 6 2 . 1 65 9 1 37.2 -36 9 - 3 12.9 -12 9 1 15 . 1 -14 0 2 3 5 1 I 5 -2 25.9 -24 5 4 - 1 . 7 -I 5 - 4 14.J 15 5 6 9.0 9 5 - 6 3.7 -0 5 » 26.3 -28 9 a t 9 0 J - 7 15 3 7 31 3 , - 9 9 3 9 0 3 - T L B .9 17 .3 11 . a a . 1 -8 . 7 -20 .5 .1 .0 .3 1 5 b . l 6 . 0 1 7 26.5 -26 .6 1 9 45.2 -•.8.4 1 11 '16.3 17.2 1 1) - 2 . 4 6.6 10 5 49 .2 4 5 . 0 10 7 - 2 . 2 -D.4 11 2 3 5 . 4 37.0 11 4 6.7 6.3 1 1 6 8.7 - 9 . 1 11 8 12.5 10.a B 1 4 0 . 5 40.9" B -1 23.2 24.0 B 3 14.9 - 1 5 . 4 b -3 8.8 - 9 . 9 8 5 10.2 10.7 8 - 5 -1.9 - 5 . 1 5 9 17.9 18.5 5 -11 10.B -11.4 5 -13 6 .2 J . O 6 0 7.8 3 . 1 6 -2 16.7 15.1 6 2 5.8 5.7 9 -5 10.7 11 9 5 2 t . 8 -21 9 - 7 27.0 -28 9 7 29.7 30 9 -9 14./ 13 9 9 12 . 4 -11 2 6 0 7 7 5 - 8 2 6 . 4 -78 5 -10 35.6 -37 5 10 23.0 24 5 - 1 2 15.J 15 6 1 8.7 - 9 6 -1 4 6 . 4 50 0 8 I 4 0 7 4 - 2 t l 4 2 48 4 - 4 6 4 4 15 .6 I .7 14 . 6 -47 .9 - 5 .3 14 . 1 .2 .5 . J .0 . a .6 .0 . 7 .1 .5 2 2 ,92.H A9 . 8 2 4 92.5 - 9 2 . 1 2 6 16.1 17.5 2 8 30.9 - 1 3 . 7 2 10 ' 5 . 6 - 7 . 0 2—T2 rBT8 11 .4 12 I 15.7 -15.1 1 2 1 7 . 0 1.0 12 5 7.2 - i . 5 12 7 6 . 6 5 . 2 13 2 6. 1 0.1 13 4 7 . 4 - 5 . 9 (j 1 I>6.4 - 2 7 . 6 6 -7 11.4 -12.2 b 9 25.B 25,0 B - 9 30.5 30.7 B -11 20.1 - 2 0 . 6 9 0 34.0 - 1 1 . 4 6 -4 2 5 . 6 25.7 6 4 4 . 0 - 2 . B 6 - 6 5 . 6 - 4 . 4 b 6 10 . 1 10.0 6 -8 2 9 . 1 29.7 b 8 4 . 8 0.0 0 0 -1.9 2 0 -2 4 . 4 -4 0 2 16.0 -16 0 -4 12.1 11 0 4 16.7 -16 0 -6 16.4 -17 t 9 5 7 3 2 6 3 18.1 -19 6 - J 2 6 . 4 -2B 6 5 27.1 -29 6 - 5 26.1 -26 6 7 36.4 1 5 6 -7 1 2 . 0 -12 6 0 4 b -2 4 - a 56 4 8 6 4 -10 5 4 10 9 .0 0 .4 -53 .0 5 . 3 6 . 4 - 9 .4 19 3 1 111 .1 105.1 3 3 39.0 -26 .8 J 5 45 .0 45.5 ) 7 10.a -10 .7 3 9 20.1 21.1 14 1 1 1.1 12.0 h=1 H 2 9.4 8.7 9 -2 3 9 . 0 38.2 9 4 2 1 . 1 2 1 . 0 9 -4 -1 .9 4 . 4 9 6 27.4 2 6 . 1 1 -6 - 2 . 0 3.1 b -10 6.7 - 4 . 7 b 10 6 . 5 3 , 6 5 - 1 2 6 . 1 L . L 0 6 - 2 , 2 - 5 0 -8 6.2 5 0 8 6 . 4 -4 0 -10 16.2 -15 1 -I b.4 - 7 7 3 1 2 7 - 1 9 . 8 - 1 0 . 4 1 26.4 -27 .2 7 - 3 a.o - a . o 6 9 9 . 4 6 6 - 1 1 1 1 . 1 -10 7 0 - 1 . 7 D 7 2 4 . 8 - 5 9 0 7 3 5 - 1 51 5 1 31 5 - 1 13 5 1 1 4 5 - 5 5 . 6 -51 . 1 31 . 5 - 12 .0 - 1 . J 2 . 2 . 8 i 13 1 0 . 2 9 . 3 4 0 1 6 . 1 15.4 4 2 32.3 - 1 2 . 5 4 4 - 1 . 4 11.0 4 6 5 3 . 4 - 5 5 . 5 0 0 65 0 -2 Bi .0 - 5 3 . 6 . 6 -77 .3 .6 90 . 4 .0 54.1 .9 6 9 . 3 *» 8 13.9 -12 .5 9 -B 2 J . 5 - 2 4 . 1 7 3 J O . 4 2U.7 7 - 5 1 1 . f l 13.8 7 5 40.9 -42 .2 7 - 7 30.7 1 2 . 5 7 7 - 2 . 1 J.O 3 -4 49 3 4 70 1 - 1 8 . J 9 1 3 10.1 11 I - 5 2 9 . 6 11 1 5 9 . 1 - 7 1 -7 16.1 17 1 7 2 4 . 4 -25 2 9 2 9 0 9 -10 5.2 2.3 0 -9 13.J - 1 1 . 4 0 1 4 . 4 2.1 7 -2 52.4 51 7 4 - 1 . 9 0 7 - 4 G.6 B 7 6 4 . 5 4 7 - 6 4 .1 2 1 B 5.0 -3 B 2 9 6 3 9 5 5 - 1 5 - 7 15 5 7 17 5 - 9 24 5 9 9 5 -11 30 . 9 2 . 1 15 . 1 -19 .0 2 .1 . 5 .0 .0 4 8 12.b -2b.9 * 10 10.5 <}.- 4 12 l i . J 10.t 5 1 28.a - 2 6 . 7 5 3 24.6 -20.8 5 5 4 8 . J -46.1 5 7 4 4 . 7 4b.7 5 9 3 B . 1 -40 .8 6 15 a 2a -10 1 1 3 10 51 .0 - 1 5 . 9 . 3 - 1. 1 ,0 - 2 9 . H 6 -34.0 . 4 5 J . 1 0 -1 5.3 -7 .1 0 J 11.5 U . 4 0 - 1 14.0 - 1 3 . a 0 5 44.9 - 4 4 . 2 0 - 5 U . O - 1 5 . 5 0 7 11 . 4 U . 7 7 -9 27.8 - 2 6 . 9 7 9 6 . J - 5 . 4 7 - t l 1 1 . 4 10.3 1 - 9 9.4 -12 1 1 5.7 3 2 0 15.0 15 2 -2 29.2 J L 2 2 24.6 -24 1 7 9 2 3 0 6.9 8.0 a -2 - 1 . 8 - 2 . 5 8 2 60.9 -60 .3 7 -8 2 3 . 0 -24 7 -10 22.6 -23 1 10 17.5 IT 7 - 1 2 1 1 . 3 9 B 1 1 9 . 4 38 9 2 3 B 5 -1J 7 6 0 19 6 - 2 6 6 2 -I 6 - 4 - 1 .2 5 .4 17 . 1 . J .1 .5 .2 D -12 19 3 12 -2 -I 54 1 12 - 3 6 J J? .1 - 1 6 . 4 . 4 12.'. 7 4 9 . 2 . a - 1 1 . 7 . 6 -5.1 .7 - J V 7 T 0 - 7 2 J . 7 23,7 1 -8 12.9 12.0 1 0 12.2 5.7 I 2 49 .7 - 5 1 . 1 I -2 24.2 - 2 4 . J 8 -4 1 3 . 5 14.0 8 4 14.5 14 . 2 B -6 18.1 - 2 0 . 6 B 6 24.0 2 J . 0 8 -B B . l - 4 . 7 B 8 - 2 . 1 6 . 4 6 0 10.7 - B . 4 6 2 1 9 . 9 38 . 2 6 4 - 1 , 6 - 4 . 0 6 6 - I . 8 9 . 0 6 G b . H -7 .9 . 2 4 19.4 - 2 0 2 - 6 8.2 5 2 6 - 2 . 4 -0 3 - 1 5.1 -6 J I 5.1 -5 5 0 6 5 4 C 3 22.2 -20 8 - 3 15.2 17 8 5 2 4 . 6 25 8 -5 4 . 2 5 8 7 26.0 -25 2 2 1 7 0 6 - 6 9 6 6 11 6 -B -2 6 8 a 6 - t o a .5 4 .4 3 .0 - J . a 8 .2 - a .4 . 8 .0 .3 .7 -5 8 1 4b -7 19 7 51 - 9 7 9 - 2 . 6 - 4 B , 4 . 6 - f c l . 2 ' . J 55.1 .0 - 2 . 1 I -4 26.8 26.5 1 6 8.9 - 9 . 6 1 - 6 21.9 -23 ,2 2 1 7.7 U .2 2 - 1 0.4 - B . 6 B -10 9 . 4 B . 6 9 - 1 2 8 , 6 - 2 8 . 0 9 I 14.8 1 5 . 7 7 -3 - 1 . 9 - 1 . 1 9 1 - 2 . 0 2 . 1 9 - 5 - 2 . 0 6 . 6 6 12 - 2 . 4 - 0 . 9 7 1 13.2 12 . 6 7 3 5.2 - 5 . 9 7 5 31 . 3 32.7 7 7 4 4 . 5 -42 .7 J 3 6 . 4 - 1 3 - 5 9 .2 6 4 0 8.5 1 4 -2 - 2 . 4 4 J .9 2 1 1 9 B H 9 7.5 5 8 - 9 21.6 -23 8 - 1 1 13 . 4 -13 9 0 14.9 14 9 2 21.J -21 8 2 I - 1 12 7 1 34 7 - J 10 7 J J L 7 -5 IB . 1 1 1 .9 - 3 D . 1 t l T f r . 0 -11 It 11 - 2 - 13 11 0 12 -2 4 1 2 19 . 4 -10 .8 2 -1.'7 .8 - 1 2 . 0 , ' .5 10.5. .8 4 1 . 7 . .2 - n . r 2 -3 6 . 0 1.4 2 5 8.2 6 .3 2 - 5 5.1 - l . t 2 - 7 11 . 0 - U . 9 3 0 14.4 -12.1 9 5 12.5 -11.a > - 7 4.7 6 . 6 7 9 to. r n . i 7 11 13 , 4 - 1 3 . 6 b 11 2 « . 6 25. 1 1 0 1U.) 7 I 2 9 B . 4 -96 9 -9 1 6 . 6 19.2 9 - 1 1 13.2 - 1 3 . 4 10 0 1 5 . 1 - 1 J . 4 9 4 3 1 . 4 - 3 2 9 - 4 20 .0 -20 9 6 - 2 . 2 -1 9 - 6 - 2 . 0 0 9 8 15.6 14 2 7 7 / -7 14 7 7 11 7 - 9 15 7 - 1 1 14 8 0 18 • il -14 . 2 13 .5 13 . 3 .2 .6 .9 « 4 4>>.7 - 4 4 . 6 - 4 19 4 23 . 9 18 . 9 - . 6 2".'. 7 .5 - 2 . 6 . 6 - J 6 . 4 .5 -12.f .0 54.5 1 4 . 27^6 29 1 -4 68.0 6B 3 -2 - 2 . 3 5.0 ) 4 21.4 - 2 0 . 9 3 - 4 25.1 - 2 4 . 1 3 - 6 19.2 18.7 4 1 22.9 - 2 4 . 6 10 -2 1 6 .i 15.8 10 2 14.1 13.1 10 -4 18 . 2 - 2 0 . 1 10 4 27.7 - J O . 6 10 - 6 3B.6 39.5 10 6 9.4 9 . 4 a 8 • -2.1 9 . / 8 10 6 . 3 -2.0 9 1 9 . 5 - 9 . 2 9 1 13.2 33.B •Y 5 4 . 4 0 . 1 9 7 -7.1 - 0 . 3 6 J5 - a I J 6 1 1 1 6 20 .7 -72 1 - 6 6J .5 -65 1 8 17.7 -IB I - 8 37.5 40 1 -10 - 2 . 0 2 I 10 4 . 7 - 4 2 5 9 -10 5.2 ' 1 10 - 9 16 . 4 -18 10 1 25.9 -25 10 - 1 12.6 12 L(J 3 2 8 . 6 28 3 0 0 a -2 4 a 2 7 a -4 a a 4 21 8 - 6 12 3 6 - 2 . 6 - a .4 - 9 .0 -21 . 9 -13 . 2 -2 . 1 . 1 .a -10 25 10 34 -12 2 7 2 12 21 J -1 10a 1 1 B6 .6 24.5 .1 - J 5 . 7 . 6 - 2 7 . 2 . B 73 . 7 .1 - 1 0 5 . 6 - .i HI . 6 4 - 1 13.8 1 1 . 5 10 -Q 6 . 2 3 . 6 10 -10 9 . J 8 . 4 11 ' -1 14.8 15.0 1 1 1 35.4 - 3 5 . 9 11 - J 13.8 15.3 9 9 i i , J - I S . 0 10 0 I B . 2 1 3 . 9 10 2 16.0 - IB . v 10 4 1 3 . 6 i i . L 10 6 I 7. J - 1 7 . 1 10 B 1.2 - 6 . 9 1 12 9 . 8 B 2 I 3B.I J5 2 -1 17.5 -14 2 J 25.1 -25 2 - 3 74.5 -73 6 1 3 5 10 6 9 . 2 -9 10 -5 26.0 26 10 7 1 1 . 8 -8 10 -7 - 2 . 2 1 t l - 8 1 4 . J 11 3 7 7 9 8 8 1 o a - i o i i 9 - 1 J9 9 I 11 9 - J l i .0 5 . J 11 . 9 -40 . 1 13 .2 14 .1 . 2 .4 . 1 .a - 3 70 3 J 12 1 -5 5 5 25 1 - 7 9 t 1 9 .9 7 1'. 4' . 6 - l f . 2 ' .9 5.7 .9 26.1 .3 &. ) .2 - 4 0 . r 0 0 207.7 -214.1 0 -2 121.6 124.4 11 -5 12.4 U . 2 It 5 1 0 . 3 9.B 1 1 -7 10.2 - 9 . 4 11 -9 - 2 . 4 - t . 3 12 0 2b,0 2 6 . 9 12 - 2 7 9 . 9 - 2 8 . 1 11 I 17 . 7 1 7 . 5 11 i 2 I.i -27 .7 11 5 70.1 - 2 3 . 6 11 7 7 . 1 - 7 . 1 12 0 SB.2 - 5 6 . 1 12 2 1 4 . 6 16.1 2 - 5 6 . 5 6 2 7 2 0 . 4 19 2 - 7 2 4 . 4 24 2 9 1 0 . 4 J L 2 - 9 4 . 8 4 6 5 7 2 6 2 86.9 -92 .2 0 -4 21.6 20.1 0 4 13.5 - 1 1 . 6 0 - 6 I0J .0 100.6 0 b 62.5 b5.9 0 - 8 36.6 - 3 6 . 4 11 2 10 . 2 - 1 1 I I -2 6 . 6 6 It 4 16.3 -17 II - 4 16.9 IB 11 b U . 2 10 2 1 J 9 0 9 3 - 2 9 -4 -i 9 5 25 9 - 7 2 1 9 7 b 9 - 9 15 . 1 - 1 . a I . 6 27 .2 22 . 5 1 .0 . 5 - 9 20 1 9 30 1 -11 5 3 i i a 1 - 1 3 14 ? 0 .6 -21.1. .6 32 . 7 . .4 - 1 . 5 . . o b. 7- .2 1 1 . » . 2 2T<T M i &.ft a . i 12 -4 IB. 1 20 .0 12 4 B.J 7 . 4 12 - 6 9 . 0 0 . 4 13 -1 8.2 5 .7 1J 1 10.5 10.1 1 2 4 - 2 . 2 - 3 . 7 12 fc 9 . 8 0 . 5 1 3 1 1.2 1 . 4 1 3 3 a . 2 - 7 . 5 13 5 - 2 . 4 - 6 . 2 14 0 2 6 . 2 6 . 8 2 -11 21.U -21 2 11 1 0 . 6 -11 2 - 1 J - 1 4 . 4 -12 3 0 149. 1 -148 3 2 23.7 -22 3 -2 8 7.J B5 2 2 0 0 18.5 -1B.4~ 0 -10 26.0 27.0 0 10 1 4 . 0 -14 .7 12 1 - 2 . 2 I 12 - 1 6.0 - 4 12 3 7.3 - 5 12 - J 1J.2 -13 12 5 - 2 . 4 -2 7 9 5 9 - 1 1 9 10 0 18 10 - 2 11 LO 2 5 10 -4 16 10 4 26 .4 tO . i -19 .3 11 . 9 4 .2 -17 . 1 25 . 3 .2 .3 . -2 20 4 2 - 1 - 4 52 4 4 U fc - 6 10 .0 - 1 7 . 4 . 1 J . 4 .5 - 4 2 . 7 .9 - 4 ? , 5 .7 1.2' 0 -12 17.4 18.5 0 -14 13.7 - 1 4 . 8 1 -1 57.2 - 5 1 , 7 1 1 - 1 15.2 13 . 6 1 1 3 6 . 6 - 8 . 5 13 - 5 7 . 6 4.8 1 4 2 1 6 , 1 - 1 4 . 9 3 4 6 8 . 1 65 J - 4 17 . 4 16 J 6 32.8 34 3 - 6 2 7. 3 28 1 8 8.0 -3 3 - 8 26.2 - 2 7 9 I 5 t I 53.7 -52 .0 1 - 3 6 4 . 2 -B3.0 1 3 42.4 -42 .2 I - 5 30.0 - 2 » . l 1 5 33.2 -34.4 1 - 7 17.1 17.0 12 - 5 - 2 . J I 12 -7 11.3 10 13 0 13.8 -11 13 2 10 . 6 -8 13 -2 10 . 4 8 13 - 4 7.5 4 9 8 B 1 0 - 6 7 10 6 5 10 - 8 16 10 -10 22 T 1 - 1 5 11 1 0 .3 -3 .6 21 .5 8 .5 . 9 .0 .9 . 5 1 2 4 3 . 2 3 9 . 1 1 4 26.8 - 2 4 . 3 1 6 11 . 4 H . 9 \ i, 24 -8 20 a 26 -10 10 10 9 -12 10 . ' - 1 1 .0 . .0 19 .1 .5 - 2 5 . 6 .b 3 . 9 .1 - 9 . 7 .2 - 9 . 0 I 0 57.6 5 1 . 4 1 2 6 7 . 4 66.3 1 -2 2 . 4 2 . 6 t 4 15.7 - 1 7 . 8 -4 11.1 9 . 6 I 10 ? ! l 7 . 5 1 12 15.2 15 . 7 1 - 8 . 5 - 7 . 6 2 1 7 1 . 7 -72.h 2 5 44 .5 4 6 . 1 1 - 10 8.5 -4 J 10 4 . a -5 3 -12 10.6 9 3 12 11.9 12 4 1 55.8 14 4 -1 IB.2 -17 8 n t 0 I 7 u . a - i 2 . i 1 -9 2B.3 2 7 . 4 1 9 32.9 1 6 , t I - 1 1 42.8 -44 .2 1 11 8 . 1 5.0 1 -13 - 2 . 1 - 1 . 9 1 1 - 3 22 11 3 5 11 - 5 17 IT 5 b LI - 7 U I t - 9 B ,0 -22 . 1 -5 .5 -17 . 6 -5 .6 13 .6 10 . 1 .3 .9 .8 . 1 12 U - L 2 5 > 1 11 - 3 54 1 5 2 •> - 5 1 1 .0 -13.B 3 20.a . 0 - J t: 4 . 4 49 ' .2 . 2 Si".* . 9 JO , i 6 31.J 3 4 . 3 1 - 6 34 .9 34.1 8 - 2 . 0 - 3 . 2 1 -B 31.0 31.1 1 - 1 0 - 1 , 8 - 0 . 2 t io i.a 8 . 4 2 9 - U 9 2 . 2 2 11 19.'» -21.1 2 13 1 1 .7 11 .1 3 2 60 . B 1 8 . 9 J 4 1 .7 - 3 . 0 4 3 64.4 -64 4 - 3 6.9 5 4 5 7.7 4 4 - 5 9.4 -7 4 7 2 2 . 1 - 2 1 4 - 7 to.a 10 2 9 4 2 6 71.5 - 6 5 . 1 2 -2 57.4 -57 .1 2 2 55.7 -55.0 2 -4 11.0 1 1 . 6 2 4 13 . 6 15.7 2 -6 5.9 l . l 0 0 72.0 7 0 -2 96.9 104 B 12 0 19 12 -2 14 12 2 b 12 -4 14 12 - 6 17 13 - 1 - 2 . 1 -IB . 4 4 . 5 14 .'4 - 2 . 3 5 4 4 -7 4 5 7 b -9 7 9 8 .7 ' - 4 J . 0 . 0 6 . 2 0 4 . 9 2 - 7 . 2 -14 12.3 -12 .1 2 1 99 .4 -94 . 4 1 - 1 - 1 . 1 - 0 . 5 2 3 28.6 31.5 - 3 34,6 - 12 . 4 0 - 4 97.5 -97 0 4 43.5 -43 0 - 6 7 1 . 6 73 0 6 4 . 2 - 6 0 -B 4.1 -5 5 2 1 9 1 8 14,7 - 1 4 . 7 i 10 14 . 9 1 5 .2 1 12 B.l - 0 . 2 4 t » 9 . J ) 5 . i 4 3 17 . 4 - 1'. . 9 4 9 20.1 20 4 - 9 4 3.1 44 4 -11 12.5 - 1 1 4 11 15 . 4 -16 4 - 1 1 12 . 4 11 0 0 0 4 2 6 5 . 6 - 5 . 5 2 -8 7.7 6 . J 2 B 14.1 14.9 2 -10 1 4 . 1 - 1 4 , 6 2 10 12.2 12.5 13 1 -2 IJ - 3 8 1 1 - 5 7 1 0 J 1 2 4 1 - 2 7 t 4 22 I -4 25 1 6 - 1 .4 - 2 .4 - 10 .7 . 0 -1 . 1 7 . 5 8 . J 23 .9 -25 . 1 . 5 . 3 .8 . 5 .2 . 9 . J i l l 7 - 1 1 10 0 25 -2 J O 2 6 • fl 12 ; b . 4 - 0 . 4 3 B.l 2 1 7 . o 7 - 1 3 . 7 9 5. J 2 5 5 . 9 10.0 2 - 5 23.9 25.B 2 7 2 B . 9 - 2 9 . 4 2 - 7 32.1 -32 .3 ? 9 19.8 -20 .1 2 - 9 1 .9 0.7 0 a 5 1 . 4 52 0 -10 4 4 . 2 46 0 10 9.8 -5 0 -12 16 . 5 - T O 0 -14 17 . 2 15 2 0 a 2 4 5 12.4 - U . O 4 7 17.5 19 . 1 4 9 - 2 . U 0 . 5 4 11 1.6 7 . 6 5 2 4 0 . 2 -51.1 5 4 15.0 14 . 7 5 0 40.0 40 5 2 2 1 . 4 20 5 - 2 29.6 -29 4 4 13.6 14 5 -4 2 6 . 4 25 5 & 12.3 -LI 0 5 3 7 2 -12 18.5 - 1 9 . 8 2 -14 5.1 0 . 4 J -1 4B.2 4 5 . 9 3 I 22.5 - 2 3 . 2 3 - 3 61.2 64.1 J 1 19.5 - 19.0 - 6 13 6 - 1 -B 6 8 -2 J 15 . 7 7 - 3 . 6 2 - b . r 9 3 . 9 . 8 ' 4 . 0 I - 0 . 2 , -11 5 . 4 - 4 . 1 11 14.4 1 1 . 4 -13 28.3 27.5 0 62.0 5 6 . 9 2 17.0 - 1 7 . 0 - 2 5.9 - 5 . 1 I t 14 . 4 -14 1 - 1 10.0 - 8 1 1 21 .0 - 2 2 1 - 5 J 9 . 2 37 1 5 4 0 . 2 41 1 - 7 4 . 9 1 0 5 7 7 5 5 t -I.I 6 . 4 5 a - 1 . 9 2.4 5 10 47.1 - 4 5 . 9 5 12 10.6 a . L 6 1 7 0 . 1 71 . 5 6 1 19 . 5 1 4 . 6 " 6 5 2 r.H-~-"2TT4- 6 7 3 7 . 7 - 3 9 . 3 6 9 19.2 15 .7 5 - 6 14 . 4 15 5 8 25.1 26 b -6 21 .5 23 5 - 1 0 b.3 -7 5 10 1 4 . 9 12 5 -12 18.0 -17 4 5 1 6 J - 5 a.5 - 9 . 7 J 5 14.7 14.7 3 - 7 46.8 45.1 3 7 24.8 25.4 3 -9 9 . 3 6 . 3 J 9 16.9 - 1 6 . 9 1 8 - 2 1 - 8 37 1 - 10 4 .8 - J ' . 7 -5 'I 10 - 2 - 12 10 1 3 l l b h. 7 0 - 5 . 4 5 10.5 4 10 . 7 4 30.3 - 2 9 . 1 -4 12.5 - 1 4 . 5 6 5.7 - 6 . 2 -6 16.1 -16 .7 8 4 8 . 9 50.7 - 8 - 1 . 7 0.5 1 7 2 2 . 3 -23 1 - 9 3 . 8 4 1 9 2 0 . 9 -21 1 -11 2 5 . 1 25 1 -13 10.b It 2 0 6 . 6 - 4 7 9 0 7 t 10 12 1 -12 4 1 -14 21 2 1 11 2 - 1 12 2 3 - 1 .9 11 .5 -2 . 4 20 . 3 10 . 5 I J . 6 - 0 .4 . 0 . 5 .2 1 10 - 3 9 6 6 40.6 -41 70.0 6b 66 .5 65 4 7 . 1 4 7 30.8 29 8. J - 7 J 1 9 3 -11 2 9 . 6 1 0 , 3 3 1 1 8 . 4 6,6 1 -13 15.2 - 1 5 . 2 4 0 50.1 - 4 6 . 6 4 -2 11.0 -10.B 4 2 4.6 - 0 . 6 6 11 14.1 - 1 i . 9 / 2 8 . 4 6 . B 7 4 22.2 21-0 - 5 46 5 29 - 7 6 7 7 -9 -2 0 -48.1 1 29.1 8 1 .6 8 7 1 1 . 4 - 10 14.5 12 . 7 10 1 7 . 5 - 1 B . 1 -17 5 . 7 2.7 1 12 . 9 13.5 -I 42.J 38.8 2 -2 64.& -64 2 2 12 . 1 -12 2 - 4 4t .O 40 2 4 34.5 - l b 2 - 6 13 . 9 -13 a 5 j 4 2 - 3 22 2 5 -1 2 - 5 3 2 7 19 2 - 7 49 2 9 IJ 2 - 9 2 3 .4 20 .8 -2 .5 20 .2 -50 .tt - 14 .0 2J . 7 . 0 " " / 6 15.6 15 . 9 7 II 24.2 - 2 1 . 9 6 -6 2B.9 2 9 - l . B 3 18.0 -20 a 6 1 4 -4 29.4 2 B . 6 4 4 24.9 24.7 4 -h 1 7 . 1 1 H O 9 b 1 4.b 6 - 9 14 . 4 -14 4 6 21.2 -23 .7 -i -L.*4 - 2 ^ 1 2 - a 31.3 31 ) - 48 - Table 15 (Continued) 1,1.2 - 47 .9 14.5 20.0 - 3 4 . 6 -12 .0 U . 4 15.T 5 -12 4 . 4 lb .2 lb .5 42. J - 4 2 . 0 t> 3 14.9 15.2 - 1 . 7 - 0 . 6 - 2 . 0 - 3 . 0 6 - 5 71 .6 23.5 30.4 - 3 3 . 5 tt - 7 7.3 ID.O 15.0 11.5 4. 7 - 5 . 0 20.5 -2 1.6 24.6 29.0 7 5.6 4.0 18.2 -1T.B 7 -2 78. 7 - 2 8 . b 27.1 - 2 8 . 4 t -4 2 7.6 -27 .b 10.2 - B . 5 7 - 6 ?b.b -29.2 6 5 .a 1 -0 5.5 - 3.8 -10 74."* 26.1 -12 a . 4 - 9 . 1 a 1 75. b -25 .5 - 1 1 7.4 -19.1 12. 3 - 1 15.0 15.) - 2 . 1 1 .1 -5 1 2 .9 -12 .5 a T 4. h 9 . 7 8 - 7 1. 1 8.9 - 9 20.2 - 2 6 . 9 B - 11 20.6 IB. b 0 it.'t 2 20.9 19.9 9 -2 2 7.1 -24.b 9 7.6 7.9 7 7.4 27 .8 - If.. 7 9 B . S l b .9 17.0 -10 1 KB -12.4 25.9 25.6 10 -1 i i ! « - 3. ) 14.3 ID 1 ' 2 1 - 16 .9 10 5 b. 1 6.2 - 5 - 2 . 1 -O.b 10 - 7 24. 5 -24.4 1 1 -B 15.4 -14 .a 0 12.4 -1 1 . 4 1 l 2 2b. 7 27.4 11.3 11.0 1 1 4 - 2 . 9 1 1 -4 22.4 - 2 2 . 7 I | -6 71. 1 21.1 r a . 9 B. 1 - 2 . 3 2.0 12 7 . 5 12 - 3 10.8 12.0 12 - 5 14. 1 14.4 17 -7 5.4 1.0 1 3 0 16.5 16.9 1 ) -2 6.5 3.9 1 3 -4. - 2 . 4 4.0 h=4 • 0 bO. T 61 .4 0 50-1 -51 .8 0 40.9 43,b 0 14.0 -1 I .6 0 *1.9 41 .8 0 4.4 -4 ,4 0 34.7 -16.8 0 - 1 . 7 2 0 . 4 0 8.8 - 7 . 9 0 7.2 - 6 . 2 0 28.7 27. 7 0 -14 1 7.0 12.1 1 33.4 15. 1 1 47.7 48.3 21.2 22.2 30.4 - 2 9 . 4 I 12.1 12.7 21.4 - IB.4 - 2 . 2 9. J t - 1 . 8 4 ,0 4 .3 - 2 . 1 1 - 11 16.0 16 . 4 11.7 21.4 24.5 44. 5 19.B -17 .9 22.1 -24 .4 17.5 23.7 - 2 . 0 21.0 16.6 19.7 -2.2 - 2 . 2 9 . 2 14.1 - 2 . 1 -20.1 ~TB~rr 14.5 12.4 -14 .4 16.4 25.8 22.0 23.1 -72.2 19. a 24.3 15.9 -15.1 h = 5 30. 9 7b.0 2 1 . 0 3a. 1 1 4 . 7 4.0 1 1 .0 2 7 . 2 - 2 b . * I 1 .0 _-U--* 59.2 -10 .2 - 2 7 . 0 73.7 2.5 ~ 6 7 0 ' 12.b 1 i .u 38.6 6.3 20.0 41.fl 15.9 37.4 * 5 . l 14.0 9.4 22.0 12.9 41.0 29.4 15.9 15.4 8.0 35..B 21.7 13.0 36.1 -45 .7 - 1 4 . 5 9 .1 ^ r r T T -11.9 - 4 1 . 1 33.1 l b . 7 12.a 18.3 - 0 . 7 15.1 - 6 . 2 - 3 b . 6 1 6 . 6 23 . 7 — - b . V - 1 6 . 5 7 . 6 21.? 14.9 16.6 -11.5 •10.2 - 2 . 9 30. I - 2 . 1 35.1 8.4 2b.0 24.8 8.4 ~V779-- 14.0 34.4 11.0 19.9 21.4 IB. 7 25.6 IB.6 12.2 19.4 35. I 15. 1 4 T 4 ~ " 6.1 2B. 1 43. 4 11.2 27.0 37.6 - 1 2 . 5 19.7 -777B - 8 . 5 12.2 b -3 2 1."2" ' - 2 5 . 6 2 8 5 5 . 4 4.2 2 a - 5 11.6 10. 0 i a - 7 9.a -9.8 1 a -9 16.2 15.0 3 8 -11 16.3 - 1 5 . 9 3 9 0 10.6 9 .3 9 2 - 2 . 3 - 2 . 1 9 -2 8.5 10.7 9 4 16 . 1 - 1 5 . 1 j 9 - 4 17.9 - I B . 5 1 9 - 6 13.2 13.7 i, 9 - 8 4.7 10 . 4 9 -10 - 2 . 4 3.0 10 1 6.4 - 3 . 6 10 -I 24.5 - 2 2 . 4 4 10 - 3 16.0 16.5 10 - 5 7.2 5.6 <, 10 - 7 7.4 - 6 . 3 4 1 1 0 16.5 1 1 . 4 11 - 2 5.3 - 3 . 7 11 - 4 6.5 - 5 . 2 5 11 - 6 10.7 - 9 . 7 5 h = 6 48.5 -49 20. 1 28. 3 20.2 23.8 12.9 6.0 35.0 11.4 . 8.9 6 . 2 11.3 19.5 21.7 -2.2 15.4 -2.2 U . C - 1 1 . 5 2 1 . 2 - 2 3 . 9 • 1 7 . 6 39.0 13.6 22.8 10.2 15.2 - 8 . 0 - 1 5 . 1 24.b 11.9 •^5675" - 8 . 7 12.8 28. 7 53.2 38. 1 23.1 - 19.1 - 2 3 . 7 h=7 21.5 -20.1 - 49 - O the distance between N(18) and the plane i s 1.20 A whereas that of o C(15) i s only 0.95 A. The bond distances and valency angles of the histamine ion are given i n Table 16, together with the corresponding values obtained by Donohue and Caron (19) for h i s t i d i n e . The bond lengths of the two analyses are i n good agreement except for the C(12)-C(13) bond i n h i s t i d i n e which i s s i g n i f i c a n t l y longer than the analogous bond i n histamine. Since the carboxyl group i s attached to the C(12) of h i s t i d i n e , the increase i n the C(12)-C(13) bond i s not s u r p r i s i n g . Considering the hydrogen bonding scheme, the probable tautomers of the imidazole r i n g are: I II III IV V Upon applying the carbon-nitrogen bond-order-length equation (20) r x = r l " ( r l " r 2 ) ( 3 x ) / ( 2 x + 1 ) where r.. = sin g l e bond length, r = double bond length, r = observed X. Z. X bond length, and x = percent double bond.character to the observed carbon-nitrogen bond lengths i n the imidazole r i n g , the C(14)-N(18), C(15)-N(16), C(17)-N(16), and C(17)-N(18) bonds were found to have - 50 - Table 16 o Bond distances (A) and valency angles (degrees) Standard deviations a(P-O) 0.009 a(O-P-O) 0.5 a(C-N) 0.018 a(< at C,N) 1.0-1 o(C-C) 0.020 a(C-H) a(X-Y-H) 9 a(N-H) 0.15 a(H-X-H) 12 a(O-H) Histamine ion H i s t i d i n e C(12) - N ( l l ) 1.494 1.495 C(12) -C(13) 1.490 1.527 C(13) -C(14) 1.498 1.508 C(14) -C(15) 1.346 1.358 C(14) -N(18) 1.379 1.386 C(15) -N(16) 1.383 1.359 C(17) -N(16) 1.311 1.314 C(17) -N(18) 1.336 1.319 N( l l ) -C(12) -C(13) 111.0 C(12) -C(13) -C(14) 114.9 C(13) -C(14) -C(15) 130.9 C(i3) -C(14) -N(18) 122.5 0(15) -C(14) -N(18) 106.4 C(14: -C(15) -N(16) 107.5 C(15] -N(16) -C(17) 108.6 C(14) -N(18) -C(17) 108.6 N(16) -C(17) -N(18) 108.8 N ( l l ] -H(20) 1.06 N ( I I ; -H(21) 0.94 N ( l l ) -H(22) 0.98 c ( i 2 : -H(23) 1.13 C(12] -H(24) 1.04 C(13} -H(25) 1.05 C ( 1 3 : -H(26) 1.06 C(15} -H(27) 1.04 N(16; -H(28] 0.95 -H(29) 1.03 N(18] -H(30] 0.93 C(12; - N ( l l ) -H(20) 98 c(i'2; )-N(ll] -H(21) 114 c ( i 2 ; >-N(ll} -H(22) 115 H(.2O; - N ( l l ) -H(21) 117 H(20: )-N(II; -H(22) 118 H(2I; )-N(II; -H(22) 96 N ( i i ; > - c(i2; -H(23) 113 N(:ll] ) - c ( i 2 : -H(24) 112 - 51 - Table 16 (Continued) C(13) -C(12) -H(23) 113 C(13) -C(12) -H(24) 107 H(23) -C(12) -H(24) 100 C(12) -C(13) -H(25) 100 C(12) -C(13) -H(26) 106 C(14) -C(13) -H(25) 108 C(14) -C(13) -H(26) 113 H(25) -C(13) -H(26) 115 C(14) -C(15) -H(27) 128 N(16) -C(15) -H(27) 125 C(15) -N(16) -H(28) 126 C(17) -N(16) -H(28) 123 N(16) -C(17) -H(29) 127 N(18) -C(17) -H(29) 124 C(14) -N(18) -H(30) 131 C(17) -N(18) -H(30) 120 Phosphate groups P(D -0(3) 1.568 P(l) -0(4) 1.556 P(D -0(5) 1.507 P(i) -0(6) 1.502 P(2.) -0(7) 1.560 P(2) -0(8) 1.561 P(2) -0(9) 1.498 P(2) -0(10) 1.487 0(3) -H(33) 0.98 0(4) -H(36) 0.83 0(7) -H(34) 0.93 0(8) -H(35) 0.74 0(3:) >-P(l)-0(4) 107.7 0(3) -P(l)-0(5) 109.3 0(3) -P(l)-0(6) 106.1 0(4) -P(l)-0(5) 105.9 0(4) -P(l)-0(6) 112.0 0(5) -P(l)-0(6) 115.8 0(7) -P(2)-0(8) 106.3 0(7) -P(2)-0(9) 107.6 0(7) )-P(2)-0(10) 111.5 0(8) -P(2)-0(9) 108.0 0(8) -P(2)-0(10) 108.0 0(9) -P(2)-0(10) 115.2 - 52 - Table 16 (Continued) P(l)-0(3)-H(33) 113 P(l)-0(4)-H(36) 114 P(2)-0(7)-H(34) 114 P(2)-0(8)-H(35) 109 Water molecule 0(19)-H(31) 0.91 0(19)-H(32) 1.02 H(31)-0(19)-H(32) 105 - 53 - 21, 20, 54, and 39 percent double bond character, r e s p e c t i v e l y . This implies 66 percent double bond character f o r C(14)-C(15) and, at the same time a t o t a l contribution of tautomers I and II of about 60%. The preponderance of these tautomers i s expected because they do not involve charge separation. The i n t e r n a l angles of the imidazole r i n g are equal to one another within the accuracy of the method. o The N(ll)-C(12) bond length of 1.494 A i s s l i g h t l y greater than the standard value of 1.479 A, but agrees well with the a-carbon- amino-nitrogen bond lengths described for other amino acids;these range o o from 1.46 to 1.52 A, the majority being close to 1.51 A i n length. The carbon-carbon bond lengths of the side chain have an average value of 1.494 A which i s s i g n i f i c a n t l y shorter than the standard p a r a f f i n i c o bond length of 1.541 A. The bond lengths and valency angles of the E^PO^ ions also are l i s t e d i n Table 16. The mean P-0 and P-OH distances of 1.561 and o o 1.499 A (with a standard error of the mean of 0.005 A) are i n agreement with those observed i n s i m i l a r compounds (21-25). The bond lengths are also i n good agreement with those predicted by iT-bonding theories for ions of t h i s type (23). Cruickshank (23) pointed out that the bond lengths for E^PO^ i n a c r y s t a l are close to the average of those i n -3 PO^ and those i n P02(0R)2 where R = a l k y l . Presumably the deviation from the P02(0R)2 bond length i s due to hydrogen bonding of H^PO^ _ o i n the c r y s t a l . The predicted values f o r E^PO^ °^ 1-50 A for P-0 and o 1.59 A for P-OH are close to the observed values. Robinson (26) has used c o r r e l a t i o n s between i . r . s t r e tching frequencies and bond lengths o _ to predict P-0 and P-OH bond lengths of 1.48 and 1.58 A for the H P0. ion. The mean 0-P-0 angle of 115.5° d i f f e r s s i g n i f i c a n t l y from the mean H0-P-0H angle of 107.0°. This deviation from a tetrahedral configura- t i o n would be expected on the basis of the electro n - p a i r repulsion theory (27). The values are close to those observed for the H^PO^ ion i n KH 2P0 4, namely, 115.4 and 105.5° re s p e c t i v e l y (21). The small differences among the various O-P-OH angles are possibly due to c r y s t a l packing. o The mean 0-H bond length i n the H^PO^ ion i s 0.87 A with a range o o o of 0.74-0.98 A (a 0.15 A). The differe n c e between 0.87 A and the o 1.04 A obtained f o r the same bond by means of neutron d i f f r a c t i o n (21) i s thought to be due to a nuclear displacement from the centre of the hydrogen electron cloud. The P-O-H angles with a mean of 112 - 9° range from 109 to 114°. o o The mean 0-H bond length i n the water molecule i s 0.97 A (a 0.15 A) and the H-0-H angle 105°, both as expected. The high temperature factors of the water molecule may be the r e s u l t of weak hydrogen bonding or a s l i g h t v a r i a t i o n i n the water content. The structure may be thought of as a leaning stack of histamine ions surrounded by a cyli n d e r of H„P0, ions and water molecules as 2 4 shown i n Figure 9. The s i g n i f i c a n t features of the complex hydrogen bonding scheme which includes s i x 0-H...0 and f i v e N-H...0 bonds and involves every active hydrogen atom, are outlined i n Figure 10 and Tables 17 and 18. The observed bond angles and bond lengths of the hydrogen bonding system suggest that a l l the hydrogen bonds have been c o r r e c t l y assigned. In addition to those assigned, N ( l l ) has a further two near oxygen Figure 9 . Projection of structure along a. - 56 - - 57 - Table 17 Distances (A) and angles (degrees) i n the hydrogen bonds X-H. . .0 (X = 0 or N) Bond X. . .0 X-H H. . .0 H-X. . , .0 Donor Acceptor (X) 0(3)-H(33). . .O(K) 1) [100] 2.55 0.98 1.59 9 OH 0 0(4)-H(36). . .0(9 I V)[101] 2.58 0.83 1.75 2 OH 0 0(7)-H(34). . .0C6 1)[000] 2.54 0.93 1.62 9 OH 0 0(8)-H(35). . .0(5 I ] [)[001] 2.57 0.74 1.84 10 OH 0 0(19)-H(31) . . .0(101)[000] 2.74 0.91 1.90 19 H 20 0 0(19)-H(32) . . .0(8 i : c) [000] 3.00 1.02 2.01 10 H 20 OH N(ll)-H(21) . . . 0 ( 1 9 n ) [101] 2.77 0.94 2.02 31 NH3+ H 90 N(ll)-H(22) . ..0(6 I V)[111] 2.86 0.98 1.96 19 NH3+ 0 N(ll)-H(20) .. .0(7 I)[000] 3.18 1.06 2.13 6 NH 3 + 0H N(16)-H(28) . . . 0 ( 9 m ) [111] 2.69 0.95 1.74 2 NH 0 N(18)-H(30) . . .0(5!)[000] 2.68 0.93 1.76 8 NH 0 Equivalent positions are shown by superior Roman numerals: I X y z II X l/2-y 1/2+z III - X - y z IV - X -l/2+y -1/2-z together with t r a n s l a t i o n i n a, b, and c indicated i n square brackets. - 58 - Table 18 Environments of atoms involved i n hydrogen bonding Atoms involved Angle i n degrees P(l)-0(3)...0(10) 121 P(l)-0(4)...0(9) 114 P(l)-0(5)...0(8) 123 P(1)-0(5)...N(18) 125 0(8)...0(5)...N(18) 96 P(l)-0(6)...0(7) 113 P(l ) - 0 ( 6 ) . . . N ( l l ) 128 0(7)...0(6)...N(11) 119 P(2)-0(7)...0(6) 123 P(2)-0(7)...N(ll) 114 0(6)... .0(7). . .N(ll) 123 P(2)-0(8)...0(5) 117 P(2)-0(8)...0(19) 121 0(5)...0(8)...0(19) 106 P(2)-0(9)...0(4) 119 P(2)-0(9)...N(16) 125 0(4)...0(9)...N(16) 108 P(2)-0(10)...0(3) 127 P(2)-0(10)...0(19) 127 0(3)...0(10)...0(19) 99 N(ll)...0(19)...0(8) 117 N(ll)...0(19)...0(10) 126 0(8)...0(19)...0(10) 115 C(15)-N(16)...0(9) 128 C(17).-N(16)...0(9) 122 C(15)-N(16)-C(17) 109 C(14)-N(18)...0(5) 133 C(17)-N(18)...0(5) 117 C(14)-N(18)-C(17) 109 C(12)-N(ll)...0(6) 106 C(12)-N(ll)...0(7) 96 C(12)-N(ll)...0(19) 89 0(6)...N(ll)...0(7) 100 0(6)...N(ll)...0(19) 143 0(7)...N(ll)...0(19) 112 - 59 - o o neighbours: 0(4) at 3.13 A and 0(5) at 3.11 A. Since the corresponding N-H...0 angles are 156 and 148° re s p e c t i v e l y , they are not l i k e l y to be bonded to N ( l l ) . Mo reover, the p o s i t i o n of H(20) favors the 0(7) bond. As indicated i n Figure 10, the water molecule i s linked v i a two 0-H...0 hydrogen bonds to the phosphate network. The water molecule accepts one hydrogen from the terminal nitrogen of histamine. The four 0-H...0 bonds between the phosphate ions are t y p i c a l of the distances reported for inorganic acids (18). The hydrogen bonds formed by the o water as a donor are 2.74 and 3.00 A, also within the usual range, (18). The histamine ion acting as a donor forms a t o t a l of f i v e N-H...0 o bonds which range from 2.66 to 3.18 A i n length and involve four d i f f e r e n t phosphate ions and one water molecule (Figure 10). Except o for the N(18)-H(30) . . .0(5) bond length of 3.18 A, the bonds are i n • the usual range (24). The geometry of th i s long bond i s otherwise quite acceptable. The N ( l l ) atom i s roughly i n a tetrahedral configuration although the 0(6)...N(ll)...0(19) angle of 143° (Table 18) does deviate appreciably from the tetrahedral value. The hydrogens of N ( l l ) approach a t e t r a - hedral arrangement much closer (Table 16). Oxygens (3) and (4) take part i n only one hydrogen bond each. A l l other oxygen atoms p a r t i c i p a t e i n two hydrogen bonds. The arrangement of covalent and hydrogen bonds around the oxygen atoms approximates p l a n a r i t y with the sum of the sets of three angles ranging between 344 and 360°. The hydrogen bonds show the usual deviation (28) from 180°, of up to about 30° as indicated i n Table 17. - 60 - There are only two other short intermolecular distances i n the o structure. One i s an N(16)...N(16) distance of 3.10 A across the centre of symmetry; the contact i s between two molecules whose planes are p a r a l l e l , and i s s l i g h t l y longer than the sum of the van der Waals r a d i i o (3.0 A). The second contact i s a C(17)-H(29)...0(3) i n t e r a c t i o n O (Figure 10). The C...0 distance i s 3.14 (a 0.017) A, the H...0 O distance i s 2.22 (a 0.15) A, and the H-C...0 angle 22°. Donohue. (28), who has described s i m i l a r contacts, concluded that they did not represent hydrogen bonds i n the same sense as 0-H...0 or N-H...0 bonds. - 61 - BIBLIOGRAPHY 1. G.H. Stout and L.H. Jensen, "X-Ray Structure Determination. A P r a c t i c a l Guide", Macmillan, New York, 1968. 2. M.J. Buerger, " C r y s t a l Structure Analysis", Wiley, New York, 1960. 3. S.C. Nyburg, "X-Ray Analysis of Organic Structures", Academic Press, New York, 1961. 4. D.M. Burns and J . I b a l l , Proc. Roy. Soc. , 227A, 200, 1955. 5. M. Kurahashi, M. Fukuyo, A. Shimada, A. Furusaki, and I. N i t t a , B u l l . Chem. Soc. Japan, 39, 2564, 1966. 6. B.N. L a h i r i , Z. K r i s t a l l o g r . , 127_, 456, 1968. 7. B.N. L a h i r i , Acta Cryst., A25, 5127, XIII-4, 1969. 8. J.D. McCullough, C. Knobler, and H. Hope, American Crystallographic Association, Winter Meeting, Seattle, Washington, 1969, Program and Abstracts, p. 52, H4. 9. T.C. Furnas, " S i n g l e - C r y s t a l Orienter Instruction Manual", Milwaukee, General E l e c t r i c Company, 1957. 10. "International Tables for X-ray Crystallography", Kynoch Press, Birmingham, volume I I I , 1962. 11. "Dictionary of ir-Electron C a l c u l a t i o n s " , W.H. Freeman, San Francisco, p. 344, 1965. 12. Chem. Soc. Special Publ., number 11, 1958 and number 18, 1965. 13. R.E. Marsh, Acta Cryst., 11, 654, 1958. 14. D.A. Wright and R.E. Marsh, Acta Cryst., 15, 54, 1962. 15. A. Chiba, T. Ueki, T. Ashida, Y. Sasada, and M. Kakudo, Acta Cryst., 22., 863, 1967. 16. L.S. B a r t e l l , J. Amer. Chem. S o c , 81, 3497, 1959. 17. H.J. Simpson and R.E. Marsh, Acta Cryst., 20, 550, 1966. 18. G.H. Stout and L.H. Jensen, "X-ray Structure Determination. A P r a c t i c a l Guide", Macmillan, New York, p. 303, 1968. - 62 - 19. J. Donohue and A. Caron, Acta Cryst., 17_, 1178, 1964. 20. J . Donohue, L.R. Lavine, and J.S. R o l l e t t , Acta Cryst., 9_, 655, 1956. 21. G.E. Bacon and R.S. Pease, Proc. Roy. S o c , A230, 359, 1955. 22. J.D. Dunitz and J.S. R o l l e t t , Acta Cryst., £, 327, 1956. 23. D.W.J. Cruickshank, J. Chem. S o c , 5486, 1961. 24. G.H. McCallum, J.M. Robertson, and G.A. Sim, Nature, 184, 1863, 1959. 25. D.E.C. Corbridge, Topics i n Phosphorus Chem., _3, 57, 1966. 26. E.A. Robinson, Canad. J . Chem., 41_, 3021, 1963. 27. R.J. G i l l e s p i e and R.S. Nyholm, Quart. Rev., 11, 339, 1957. 28. J . Donohue, i n "S t r u c t u r a l Chemistry and Molecular Biology", ed. A. Rich and N.Davidson. Freeman, San Francisco, p. 433, 1968.

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