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 Cu-I linear polymer, {Cu-6(mu(3)-SC5H4NH)(4)(mu(2)-SC5H4NH)(2)(I-4)(mu-I)(2)-}(n).2nCH(3)CN (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 (mu(3)-S) to form a centrosymmetric hexanuclear repeat unit, Cu6S6I4(mu-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 mu(3)-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(mu-I)(2)Cu core, while a third copper(l) center is terminally bonded to another iodide ligand. Polymer 2 is also rare, and the first triangular cluster of Cu-I with an heterocyclic thioamide.