Crystal structure of the tetra­aqua­bis­(thio­cyanato-κN)cobalt(II)–caffeine–water (1/2/4) co-crystal

In the structure of the title compound [systematic name: tetra-aqua-bis-(thio-cyanato-κN)cobalt(II)-1,3,7-trimethyl-1,2,3,6-tetra-hydro-7H-purine-2,6-dione-water (1/2/4)], [Co(NCS)2(H2O)4]·2C8H10N4O2·4H2O, the cobalt(II) cation lies on an inversion centre and is coordinated in a slightly distorted octa-hedral geometry by the oxygen atoms of four water mol-ecules and two N atoms of two trans-arranged thio-cyanate anions. In the crystal, the complex mol-ecules inter-act with the caffeine mol-ecules through O-H⋯N, O-H⋯O and C-H⋯S hydrogen bonds and π-π inter-actions [centroid-to-centroid distance = 3.4715 (5) Å], forming layers parallel to the ab plane, which are further connected into a three-dimensional network by O-H⋯O and O-H⋯S hydrogen bonds involving the non-coordinating water mol-ecules.