Crystal structure of tetra-aqua-bis-(1,3-dimethyl-2,6-dioxo-7H-purin-7-ido-κN(7))cobalt(II).

The title complex, [Co(C7H7N4O2)2(H2O)4], comprises mononuclear mol-ecules consisting of a Co(II) ion, two deprotonated theophylline ligands (systematic name: 1,3-dimethyl-7H-purine-2,6-dione) and four coordinating water mol-ecules. The Co(II) atom lies on an inversion centre and has a slightly distorted octa-hedral coordination environment, with two N atoms of two trans-oriented theophylline ligands and the O atoms of four water mol-ecules. An intra-molecular hydrogen bond stabilizes this conformation. A three-dimensional supra-molecular network structure is formed by inter-molecular O-H⋯O and O-H⋯N hydrogen bonds.