Enhanced π-backdonation from gold(i): Isolation of original carbonyl and carbene complexes
Résumé
The specific electronic properties of bent o-carborane diphosphine gold(I) fragments were exploited to obtain the first classical carbonyl complex of gold [(DPCb)AuCO]+ (ν(CO) = 2143 cm-1) and the diphenylcarbene complex [(DPCb)Au(CPh2)]+ , which is stabilized by the gold fragment rather than the carbene substituents. These two complexes were characterized by spectroscopic and crystallographic means. The [(DPCb)Au]+ fragment plays a major role in their stability, as substantiated by DFT calculations. The bending induced by the diphosphine ligand substantially enhances π backdonation and thereby allows the isolation of carbonyl and carbene complexes featuring significant π-bond character. © 2014 Wiley-VCH Verlag GmbH &Co. KGaA,Weinheim.