Synthesis and crystal structure of poly[[di-μ3-tetrathioantimonato-tris[(cyclam)cobalt(II)]] acetonitrile disolvate dihydrate] (cyclam = 1,4,8,11-tetraazacyclotetradecane)

Abstract

Reaction of Co(ClO4)2·6H2O with cyclam (cyclam = 1,4,8,11-tetraazacyclotetradecane) and Na3SbS4·9H2O (Schlippesches salt) in a mixture of acetonitrile and water leads to the formation of crystals of the title compound with the composition {[Co3(SbS4)2(C10H24N4)3]·2CH3CN·2H2O}n or {[(Co-cyclam)3(SbS4)2]·2(acetonitrile)·2H2O}n. The crystal structure of the title compound consists of three crystallographically independent [Co-cyclam]2+ cations, which are located on centers of inversion, one [SbS4]3− anion, one water and one acetonitrile molecule that occupy general positions. The acetonitrile molecule is disordered over two orientations and was refined using a split model. The CoII cations are coordinated by four N atoms of the cyclam ligand and two trans-S atoms of the tetrathioantimonate anion within slightly distorted octahedra. The unique [SbS4]3− anion is coordinated to all three crystallographically independent CoII cations and this unit, with its symmetry-related counterparts, forms rings composed of six Co-cyclam cations and six tetrathioantimonate anions that are further condensed into layers. These layers are perfectly stacked onto each other so that channels are formed in which acetontrile solvate molecules that are hydrogen bonded to the anions are embedded. The water solvate molecules are located between the layers and are connected to the cyclam ligands and the [SbS4]3− anions via intermolecular N—H...O and O—H...S hydrogen bonding.

Keywords

• crystal structure
• cobalt thioantimonate
• layered structure
• hydrogen bonding