Crystal structure of a pentanuclear gold-silver cluster complex

The title compound, [C₁₆H₃₆N]⁺[C₄₈H₃₀Au₃Ag₂]^-, crystallizes in the triclinic space group P1^-1, with a=18.199(12), b=19.210(8), c=19.270(9)Å, α=71.34(3)°β=76.43(4)° γ=72.95(5)° and Z=4, with two independent molecules in the asymmetric unit. The structure was solved by direct methods and refined by full-matrix least squares methods to R=0.072 for 3739 observed reflections. The metal atoms have a trigonal-bipyramidal arrangement with the three Au atoms forming an equilateral triangle and two Ag atoms occupying apical positions. Each Au atom is σ-bonded to phenylethynyl ligands in a linear coordination. Each Ag atom is asymmetrically pi-bonded to three alkyne groups. The Au-Au distances lie in the range of 3.934-4.010 A, indicating the lack of Au-Au bond.