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

The title complex, [Co(CHNO)(HO)], comprises mononuclear mol-ecules consisting of a Co ion, two deprotonated theophylline ligands (systematic name: 1,3-dimethyl-7-purine-2,6-dione) and four coordinating water mol-ecules. The Co atom lies on an inversion centre and has a slightly distorted octa-hedral coordination environment, with two N atoms of two -oriented theophylline ligands and the O atoms of four water mol-ecules. An intra-molecular hydrogen bond stabilizes this conformation.