SYNTHESIS AND CRYSTAL-STRUCTURE OF CYANO(TRIMETHYLPHOSPHINE)GOLD(I)

The crystal structure of [AuCN{P(CH3)3}], M(r) = 299.063, has been determined at room temperature from single-crystal X-ray intensity data. The space group is triclinic, P1BAR, with a = 9.031(2), b = 9.481(2), c = 13.990(4) angstrom, alpha = 76.03(1), beta = 79.64(2), gamma = 75.61(2)-degrees, V = 1116.8(3) angstrom 3, Z = 6, D(x) = 2.67 Mg m-3, lambda(Mo K-alpha) = 0.7107 angstrom, mu = 19.81 mm-1 and F(000) = 134. The refinement for the positional and thermal parameters, carried out by full matrix least-squares calculations, converged to R = 0.055 and R(w) = 0.069 for 2415 reflections with I > 3-sigma(I). There are three [AuCN{P(CH3)3}] complexes in the asymmetric unit with P-Au-C angles close to linear, between 178.4 and 178.8-degrees. The complexes are stacked along a in a staggered conformation so that an infinite zig-zag-shaped array of gold atoms is formed. Within a chain the angles Au-Au-Au are between 138 and 140-degrees and the Au-Au distances between 3.24 and 3.32 angstrom. Since there are no ligand bridges between the gold atoms, the fairly short gold-gold distances indicate weak metal-metal bonding. It is thus justified to formulate the compound as [AuCN{P(CH3)3}]infinity. There are only van der Waals interactions between the chains.