Unexpected gold-containing boride clusters formed from the reactions of [RhRu3H(η5-C5Me5)(CO)9BH]– with gold(I) phosphine derivatives: crystal structures of [RhRu3H(η5-C5Me5)(CO)9B{Au(PPh3)}2(AuCl)]·CH2Cl2 and [RhRu3H(η5-C5Me5)(CO)9B{Au2(dppf)}(AuCl)]·CH2Cl2[dppf = 1,1′-bis(diphenylphosphino)ferrocene]
Abstract
The deprotonation of [RhRu3H(η5-C5Me5)(CO)9BH2] occurred by loss of an M–H–B bridging hydrogen atom to give [RhRu3H(η5-C5Me5)(CO)9BH]–1; indirect evidence suggests the Rh–H–B proton has been removed. Anion 1 reacts with [AuCl(PPh3)] or [Au2Cl2(dppf)][dppf = 1,1′-bis(diphenylphosphino)ferrocene] to yield [RhRu3H(η5-C5Me5)(CO)9B{Au(PPh3)}2(AuCl)]2 and [RhRu3H(η5-C5Me5)(CO)9B{Au2(dppf)}(AuCl)]3 respectively rather than expected derivatives of the type [RhRu3(η5-C5Me5)(CO)9BH3 –x(AuL)x](x= 1, 2 or 3). The single crystal structures of 2·CH2Cl2 and 3·CH2Cl2 have been determined: 2·CH2Cl2, monoclinic, space group P21/c, a= 11.944(4), b= 40.870(6), c= 13.313(4)Å, β= 108.66(2)°, Z= 4, R= 0.0684; 3·CH2Cl2, monoclinic, space group P21/c, a= 11.919(2), b= 39.350(8), c= 13.520(4)Å, β= 108.62(2)°, Z= 4, R= 0.0584. The trigold derivative [RhRu3(η5-C5Me5)(CO)9B{Au(PPh3)}3] was formed either by treating 1 with [{Au(PPh3)}3O][BF4] or treating 2 with PPh3 in the presence of Tl[PF6] or [N(PPh3)2]Cl. The chloride ligand in compound 2 was replaced by iodide through reaction with [NEt4]I. Anion 1 also reacted with [Au2Cl2(dppa)][dppa = bis(diphenylphosphino)acetylene] to give the linked dicluster species [{RhRu3H(η5-C5Me5)(CO)9B(AuCl)}2{µ-Au(dppa)Au}2].