Construction of a Novel Copper(I) Chain Polymer of Hexanuclear Cu6(2-SC5H4NH)6I6 Cores with A New (μ3-S) Mode of Bonding of Pyridine-2-thione and of an Unusual Triangular Cu3I3(dppe)3(2-SC5H4NH) Cluster

The reactions of copper(I) iodide with pyridine-2-thione (2-SC5H4NH) in the presence of a series of diphosphane ligands, Ph2PXPh2P {X = (CH2)m, m = 1(dppm), 2 (dppe), 3 (dppp), 4 (dppb); CHCH (dppen)}, yielded an iodo-bridged hexanuclear CuI linear polymer, {Cu63-SC5H4NH)42-SC5H4NH)2(I4)(μ-I)2}n·2nCH3CN (1). A similar reaction with 1,2-bis(diphenylphosphino)ethane (dppe) and 2-SC5H4NH yielded a triangular cluster, Cu3I3(dppe)3(2-SC5H4NH), 2. In the chain polymer 1, three Cu(I) iodide and three 2-SC5H4NH ligands combined via bridging S donor atoms to form a boat-shaped trinuclear Cu3S3I3 core, and two such cores combined in an inverse manner via four S-donor atoms (μ3-S) to form a centrosymmetric hexanuclear repeat unit, Cu6S6I4(μ-I)2-, which finally formed the iodo-bridged infinite linear chain polymer 1. Linear chains are separated by the nonbonded acetonitrile molecules. Polymer 1 is the first such example of a linear chain formed by the hexanuclear Cu6S6I6 core in copper chemistry as well as in metal−heterocyclic thioamide chemistry. In addition, it has the first μ3-S mode of neutral pyridine-2-thione ever reported. In the moiety Cu3I3(dppe)3 of 2, two copper(I) centers are bridged by the iodide ligands forming a Cu(μ-I)2Cu core, while a third copper(I) center is terminally bonded to another iodide ligand. Polymer 2 is also rare, and the first triangular cluster of CuI with an heterocyclic thioamide.