Crystal structures of two Co(NCS)(2) urotropine coordination compounds with different Co coordinations.

The reaction of Co(NCS)(2) with urotropine in ethanol leads to the formation of two different compounds, namely, bis-(ethanol-κO)bis-(hexa-methyl-ene-tetra-mine-κN)bis-(thio-cyanato-κN)cobalt(II)-di-aqua-κ (2)O-bis-(hexa-methyl-ene-tetra-mine-κN)bis-(thio-cyanato-κN)cobalt(II)-ethanol-hexa-methyl-ene-tetra-mine (1.2/0.8/1.6/4), [Co(NCS)(2)(C(6)H(12)N(4))(2)(C(2)H(6)O)(2)](1.2)·[Co(NCS)(2)(C(6)H(12)N(4))(2)(H(2)O)(2)](0.8)·1.6C(2)H(6)O·4C(6)H(12)N(4), 1, and tris-(ethanol-κO)(hexa-methyl-ene-tetra-mine-κN)bis(thio-cyanato-κN)cobalt(II), [Co(NCS)(2)(C(6)H(12)N(4))(C(2)H(6)O)(3)], 2. In the crystal structure of compound 1, two crystallographically independent discrete complexes are observed that are located on centres of inversion. In one of them, the Co cation is octa-hedrally coordinated to two terminal N-bonded thio-cyanate anions, two urotropine ligands and two ethanol mol-ecules, whereas in the second complex 80% of the coordinating ethanol is exchanged by water. Formally, compound 1 is a mixture of two different complexes, i.e. di-aqua-dithio-cyanato-bis-(urotropine)cobalt(II) and di-ethano-ldi-thio-cyanato-bis-(uro-trop-ine)cobalt(II), that contain additional ethanol and urotropine solvate mol-ecules leading to an overall composition of [Co(NCS)(2)(urotropine)(2)(ethanol)(1.2)(H(2)O)(0.8)·0.8ethanol·4urotropine. Both discrete complexes are linked by inter-molecular O-H⋯O and O-H⋯N hydrogen bonding and additional urotropine solvate mol-ecules into chains, which are further connected into layers. These layers combine into a three-dimensional network by pairs of centrosymmetric inter-molecular C-H⋯S hydrogen bonds. In the crystal structure of compound 2, di-thio-cyanato-(urotropine)tri-ethano-lcobalt(II), the cobalt cation is octa-hedrally coordinated to two terminal N-bonded thio-cyanate anions, one urotropine ligand and three ethanol mol-ecules into discrete complexes, which are located in general positions. These complexes are linked by inter-molecular O-H⋯N hydrogen bonding into layers, which are further connected into a three-dimensional network by inter-molecular C-H⋯S hydrogen bonding.