Further refinement of the crystal structure of neovitamin B12

Abstract

The molecular structure of neovitamin B₁₂ has been elucidated by X-ray crystallographic analysis from diffractometer data. The crystal structure was solved by means of the anomalous dispersion technique and shown to be cyano-13-epicobalamin, an isomer of cyanocobalamin, vitamin B₁₂. Both vitamin B₁₂ and neovitamin B₁₂ are parent compounds of two isomeric series. The compound crystallises in space group P2₁2₁2₁ with Z= 4 in a unit cell of dimensions: a= 24·98, b= 22·06, c= 15·74 Å. The structure was refined by least-squares techniques to R 0·159 for 2986 independent reflections.