From Cu(I) and Cu(I)-Cu(II) mixed-valence clusters to 2D Cu(II) and Cu(I) coordination polymers supported by a flexible bis-tetrazole organosulfur ligand.

Three coordination compounds from the reaction of copper(II) bromide with the flexible bis-tetrazole organosulfur ligand, 1,2-bis(1-methyl-1 H -tetrazole-5-ylthio)ethane (bmtte) have been isolated and characterised. The identification of polymeric 2∞Cu 2 Br 4 (bmtte) (1), trinuclear [Cu 3 Br 4 (bmtte) 2 ] (2) and tetranuclear [Cu 2 Br 2 (bmtte)] 2 (3) compounds shows that the reaction conditions have a significant influence on the structure of the complexes formed. Moreover, two polymorphs of the 2D Cu(II)-coordination polymer 1 have been isolated and these crystallise in the monoclinic C 2/ m (1m) and the triclinic P 1̄ (1t) space groups. The thermal stabilities and behaviour in aqueous media of compounds 1-3 were investigated along with the reactivity of compound 2 with CuBr 2 and KI. The solid-state reaction between mixed-valence compound 2 with KI or the direct reaction of CuI and bmtte under microwave irradiation allowed the preparation of the polymeric 2∞Cu 4 I 4 (bmtte) 2 (4). The redox behaviour of complexes 2 and 3 was analysed by cyclic voltammetry.