Isolation of Bis‐ and Mono‐Cyclometallated Ru−IMes Complexes upon Reaction of [Ru(PPh3)3HCl], IMes and ZnMe2

Abstract

AbstractAddition of an excess of ZnMe2to a mixture of [Ru(PPh3)3HCl] and IMes (IMes=1,3‐bis(2,4,6‐trimethylphenyl)imidazolin‐2‐ylidene) yields the bis‐cyclometallated complex, [Ru(IMes)“(PPh3)2]2, together with the mono‐cyclometallated, Ru−Zn heterobimetallic complex [Ru(IMes)′(PPh3)2(ZnMe)]3. Treatment of2with H2, PhSiH3or pinacolborane yields the previously reported complex, [Ru(IMes)′(PPh3)2H]1, the synthesis of which has been reinvestigated. Further studies of small molecule reactivity show that1adds H2to give [Ru(IMes)(PPh3)2H4]4, whilst2reacts with catecholborane to give [Ru(IMes‐Bcat)′(PPh3)2H]5, in which (IMes‐Bcat)′ signifies a borylated NHC ligand that is singly‐metallated onto Ru. Treatment of2with CO gives the 18‐electron dicarbonyl product [Ru(IMes)”(PPh3)(CO)2]6. Compounds1–3,5and6have been structurally characterised.