Use of [Re6Q8(CN)6]4− (Q = S, Se, Te) cluster anions and Cu(I) cationic complexes with 2,2′-bipyridine for the construction of new cyano-bridged coordination compounds

Abstract

A series of four new coordination compounds [{Cu(bpy)2(μ-CN)Cu(bpy)}2Re6S8(CN)6]·bpy·2H2O (1), [{Cu(bpy)}2(μ-CN)][{Cu(bpy)}3Re6S8(CN)6] (2) and [{Cu(bpy)(μ-CN)Cu(bpy)}2{Cu(bpy)}2Re6Q8(CN)6] (3, Q=Se; 4, Q=Te) have been synthesized by the reactions of hexanuclear rhenium(III) chalcocyanide complexes, CuCN and 2,2′-bipyridine (bpy) under hydrothermal conditions. Compound 1 was characterized by single-crystal X-ray diffraction analysis, compounds 2–4 were characterized by a set of methods, including IR spectroscopy, thermal analysis, elemental analysis, EDS, and single-crystal X-ray diffraction analysis. 1 has a molecular structure, in which two cyano groups of cluster anion [Re6S8(CN)6]4− are N-bonded to the dimeric mixed-valent cations {Cu(bpy)2(μ-CN)Cu(bpy)}2+ through axial coordination to the Cu+ cations. In 2, the cluster anions provide all of their six cyano groups for coordination with the copper centers of {Cu(bpy)}+ moieties, giving rise to a 3D framework in which the cavities are occupied by the dimeric cations [{Cu(bpy)}2(μ-CN)]+. 3 and 4 are isostructural and have a 1D chain structure, in which four equatorial cyano groups of cluster anions are N-bonded to the {Cu(bpy)}+ bridging fragments, while two axial cyano groups are terminated by dimeric cations {Cu(bpy)(μ-CN)Cu(bpy)}+. The compounds synthesized appear to be the first examples which combine hexanuclear rhenium(III) chalcocyanide clusters and monovalent Cu(I) ions.