SYNTHESIS AND CHARACTERIZATION OF THE TRIANGULO RAFT CLUSTER [(AGCO(CN(2,6-C6H3ME2))4)3], A BIMETALLIC HEXANUCLEAR ISONITRILE CLUSTER

The trimer [{AgCo(CNPh*)4}3] (1, Ph* = 2,6-C6H3Me2) has been established by a single-crystal X-ray diffraction study to have a triangulo raft structure (space group P1BAR, with a = 14.738 (3) angstrom, b = 14.717 (3) angstrom, c = 22.693 (5) angstrom, alpha = 84.29 (3)-degrees, beta = 81.74 (3)-degrees, gamma = 89.55 (3)-degrees, D(c) = 1.421 g/mL, Z = 2, and R(F) = 5.62%). The raft contains an equilateral triangle of silver nuclei with a "Co(CNPh*)4" fragment bridging each edge. All of the isonitriles are essentially linear, and each cobalt has one isonitrile ligand radial to the raft and three with close contacts to silver. Structural analysis suggests that these close contacts do not correspond to significant bonding interactions, and that the raft is best described as a cluster of [Co(CNPh*)4]- anions held together by Ag+ cations.