X-ray and neutron diffraction studies of the crystal and molecular structure of the predominant monocarboxylic acid obtained by mild acid hydrolysis of cyanocobalamin. Part II. X-ray diffraction studies of wet crystals

The crystal and molecular structure of wet crystals of the O-monocarboxylic acid of cyanocobalamin has been determined. The molecule crystallizes in a monoclinic cell ofa = 14.845,b = 17.435,c = 16.243 A, β = 103.54°, space group P2₁,. Intensity data were collected by diffractometry and the structure solved by Patterson and Fourier methods. Refinement, initially by a least-squares process and latterly by Fourier methods, led to anR of 0.140. Disordered sites were found for the terminal atoms of side chaine; the identification of the acid grouping was not made with certainty. Sites for sixteen water molecules were determined.