The syntheses, structures and redox properties of phosphine-gold(I) and triruthenium-carbonyl cluster derivatives of tolans

The syntheses of several ethynyl-gold(I)phosphine substituted tolans (1,2-diaryl acetylenes) of general form [Au(CCC6H4CCC6H4X)(PPh3)] are described [X = Me (2a), OMe (2b), CO2Me (2c), NO2 (2d), CN (2e)]. These complexes react readily with [Ru3(CO)10(μ-dppm)] to give the heterometallic clusters [Ru3(μ-AuPPh3)(μ-η1,η2-C2C6H4CCC6H4X)(CO)7(μ-dppm)] (3a–e). The crystallographically determined molecular structures of 2b, 2d, 2e and 3a–e are reported here, that of 2a having been described on a previous occasion. Structural, spectroscopic and electrochemical studies were conducted and have revealed little electronic interaction between the remote substituent and the organometallic end-caps.