Highly Reduced Organometallics. 5. Synthesis, Properties, and the Molecular Structure of (Ph3PAu)3V(CO)5, A Gold-Vanadium Cluster

Article abstract of DOI:10.1021/ja00410a020

The unusual metal cluster tris((triphenylphosphine)gold)pentacarbonylvanadium, (Ph3PAu)3V(CO)5 (1), has been synthesized by treatment of sodium or cesium salts of the pentacarbonylvanadate(3-) ion, V(CO)5^3-, with chloro(triphenylphosphine)gold in liquid ammonia (10-15percent yields) or in tetrahydrofuran (50-60percent yields).An X-ray crystallographic structure determination of this substance shows that 1 is the first neutral derivative of the unknown tetrahedral cluster (Ph3PAu)4 as well as the only established mixed-metal cluster containing vanadium.In 1 eight-coordinate vanadium is bound to a novel tridentate tris(triphenylphosphyne)trigold ligand containing gold-gold bonds.All four metal atoms form a slightly distorted tetrahedral cluster.The V(CO)5 group in 1 is best described as being a pseudooctahedral fragment which is bound to a large trigold unit.Infrared spectra of 1 support this view as they resemble those of the octahedral anions V(CO)5L^-, where L = PR3, CNR, etc.Chemical reactivity studies demonstrate that 1 is a remarkably robust gold-vanadium carbonyl complex.Triphenylphosphine, soluble halide, and acetonitrile which normally cause facile heterolytic cleavage of gold-vanadium bonds at room temperature are found to have no effect on 1.Crystal data: space group (*), a = 12.840 (6) Angstroem, b = 19.088 (6) Angstroem, c = 12.380 (4) Angstroem, α = 93.82 (3) deg, β = 117.26 (3) deg, γ = 92.02 (3) deg, Z = 2, V = 2684 (4) Angstroem³, and ρ(calcd) = 1.941 g/cm³.