Abstract
Two new cyanido-bridged coinage metal compounds are presented. A novel hetero trinuclear Ag-Cu-Au compound of formula [AgCuAu(CN)(3)(PPh3)(5)](H2O)(2) 1 is described with bridging cyanide ligands between the metals, and terminal phosphane ligands for Cu(I) and Ag(I). Silver is tetrahedrally coordinated by 3 phosphane ligands and a bridging cyanido ligand, copper is coordinated tetrahedrally by 2 phosphanes, and 2 bridging cyanide ligands, whereas gold has a linear coordination by 2 cyanido-kappa C ligands. Under slightly different synthetic conditions, an alternating chain compound [AuCu(CN)(2)(PPh3)(2)](H2O)(2) 2 was found, isostructural with the related Ag- Cu compound. In 2, Cu(I) is tetrahedrally coordinated by 2 phosphane ligands and 2N atoms of the bridging cyanido ligand to the Au(I). The qualitative solid-state luminescence emission intensity of 1 is reported and compared with that of the related bimetallic Au-Cu, Ag-Cu, Ag-Ag and Ag-Au cyanido-bridged chain compounds. The luminescence of 2 was found somewhat stronger than that of 1. The electronic molecular orbitals were calculated by DFT, where a strong contribution of Cu(I) orbitals in HOMO/LUMO character of the two complexes is observed. (C) 2014 Elsevier B.V. All rights reserved.