CoI 2(C 6H 4N 3CH 2CO 2C 4H 2SCO 2CH 2C 6H 4N 3)], a coordination polymer containing the thiophene-2,5-di(carboxylatomethylenebenzotriazole) bridging ligand: synthesis, structure, redox properties

Abstract

The title complex was obtained by reacting CoI 2 with thiophene-2,5-di(carboxylatomethylenebenzotriazole) in dichloromethane. The single-crystal X-ray structure analysis of the green material reveals a polymeric chain of CoI 2 units, tetrahedrally coordinated and connected by the 3-nitrogen atoms of the two benzotriazole groups of the multifunctional ligand. The paramagnetic cobalt(II) polymer can be oxidised by hexachloroethane to give the corresponding cationic cobalt(III) complex [CoI 2(C 6H 4N 3CH 2CO 2C 4H 2SCO 2CH 2C 6H 4N 3)(H 2O) 2] + which is diamagnetic and precipitates as the green–yellow chloride salt.