Crystal Structure of Vitamin B₁ and of Adenine Hydrochloride

Abstract

CRYSTALS of vitamin B₁ (hydrochloride) from various sources have been examined. All have been found to be substantially identical in form and X-ray patterns. A very slight difference in optical properties may, however, point to the existence of a variable amount of impurity in solid solution. The angle between the c axis and the principal direction γ is 19° 40′ ± 20′, 19° 20′ ± 20′, 19° 20 ± 20 and 19° 0′ ± 20′ in four specimens prepared respectively by Windaus and Tschesche, Jansen and Donath, and Peters (two specimens separated at different pH). The crystals were monoclinic, tabular on b and slightly elongated along c, showing faces (010), (110), (Oil), and sometimes (1 KT) and (2 KT). The cell dimensions are: a = 12.62 A.; b = 20.53 A.; c = 6.96 A.; = 66° 5. The space group is probably Assuming four asymmetric molecules per cell and the measured density 1.43, the molecular weight is 358, in good agreement with 355 calculated from the formula of Windaus¹, C₁₂H₁₈O₂N₄S, 2HCl. The optical properties are: optic axial plane b, is 19° 20 from c in acute angle; optic axial angle large, undeter mined, sign probably negative, birefringence high.