Golden Ring With Aesthetic Appeal

Metal-oxygen-metal linkages in organometallic complexes underpin many applications in heterogeneous catalysis and in electro-optical and magnetic applications. But little is known about less common metal-carbon-metal linkages and the role they might play in catalysis and electronics. In a bid to learn more, Anthony F. Hill and coworkers at Australian National University have been exploring the synthesis of metallacarbyne complexes of the type L_nM≡C–M´L´_n, where M represents different metals and L various ligands. They have now discovered that the reaction between a W≡C–Sn version of the complex and a gold reagent leads to an unprecedented tetrameric gold-carbon ring (J. Am. Chem. Soc., DOI: 10.1021/ja400128h). Hill says making the Au₄C₄ ring complex (shown) is very much a case of aesthetic appeal, as he doesn’t anticipate that the complex will have any direct application to catalysis or any interesting photophysical properties. However, monomeric versions of the gold carbyne might serve to expedite transfer of carbido groups from tin to palladium in a catalytic manner. “A long way down the line, it will be interesting to see if these carbyne complexes do indeed have a role to play in molecular electronics,” he adds.