Crystal structure of N-(5-O-phosphopyridoxyl)-L-tyrosine heptahydrate

Abstract

The structure of the title compound has been solved from diffractometer data by direct methods and refined by least-squares techniques to R 0·082 for 1734 observed reflexions. Crystals are monoclinic, space group P2₁, with unit-cell dimensions a= 10·575(5), b= 8·985(5), c= 14·930(7)Å, β= 115·9(2)°. The two aromatic rings are nearly parallel, the dihedral angle between their mean planes being 178·4°. A strong intermolecular hydrogen bond [O(5)⋯ O(6^I) 2·52 Å] joins tow molecules related by a 2_I axis. The packing is mainly built from a three-dimensional network of hydrogen bonds, involving in particular the seven water molecules.