The reactions of the five-membered cyclic osmacarbyne complex, i.e., osmapentalyne, with a complete set of coinage metal (Cu, Ag, and Au) complexes have been investigated. Osmapentalyne 1 reacts with CuCl or AuCl(PPh3) via its metal–carbon triple bond, leading to the formation of osmapentalyne-copper(I) chloride adduct 2 or osmapentalyne-gold(I)-triphenylphosphine adduct 3, respectively. Moreover, it can react with AgOTf in the presence of 1,10-phenanthroline to give osmapentalyne-silver(I)-phenanthroline adduct 4. All the compounds have been characterized by X-ray diffraction analysis. The formation of these bimetallic adducts can be regarded as the “alkyne-like” interaction of an osmium–carbon triple bond with the coinage metal center. The interaction is weak and these adducts can readily dissociate to regenerate precursor osmapentalyne 1 in essentially quantitative yield with the assistance of PPh3 or chloride ligands.
