Golden Chains and Cartwheels

Abstract

CHEMISTRY Gold atoms in the +1 oxidation state can exhibit strong noncovalent interactions. Bachman et al. planned to take advantage of this property of gold(I) thiolates to build supramolecular assemblies. However, the compounds they synthesized, isonitrilegold(I) phenylthiolates (RNCAuSPh, where R = n -alkyl), apparently polymerized into [PhSAu] n , where the monomers are chained through Au-Au and Au-S bonds. The ethyl precursor reacted almost immediately and, unlike other forms of PhSAu previously synthesized, the product exhibited orange-red luminescence; with the longer n -heptyl reactant, the polymerization could be slowed, and the intermediate compound retaining the isonitrile could be isolated and characterized. Organometallic complexes that contain two different metals may provide insight into intermetallic bonding and may have applications in catalysis. Cerrada et al. have synthesized an unusual complex, in which a silver atom is surrounded by six gold atoms where alternate atoms are slightly above or below the plane of the cartwheel. The bond lengths in the crystal structure indicate that true intermetallic bonds are formed, and nuclear magnetic resonance spectra indicate that the cartwheel structure persists in solution. Two other complexes, containing five gold atoms and one silver or copper atom, could not be crystallized but appeared to form similar structures. — PDS; JU J. Am. Chem. Soc. , in press; Angew. Chem. Int. Ed. 39 , 2353 (2000).