Synthesis, characterization, and X-ray structures of three iridium(III)-hydrido-cyclometallated-imine complexes, including the first reported hydrido-(eta(1)-imine)-Ir complex

Reactions of cis,trans,cis-[Ir(H)(2)(PPh3)(2)(solv)(2)]PF6 (solv = MeOH or Me2CO) with the imines HN=CPh2, (o-HOC6H4)C(Me)=NCH2Ph, and PhC(H)=N(p-F-C6H4) in MeOH or acetone under Ar give the complexes [IrH{NH=C(Ph)(o-C6H4)}(NH=CPh2)(PPh3)(2)]PF6 (3), [IrH{PhCH2N=C(Me)(o-C6H3OH)}(solv)(PPh3)(2)]PF6, where solv = MeOH (4) or Me2CO (4a), and [IrH{N(p-F-C6H4)=CH(o-C6H4)}(Me2CO)(PPh3)(2)]PF6 (5a), which have been isolated and characterized. The imine (C6F5)C(H)=NPh is unreactive toward the Ir precursors. The X-ray structures of 3, 4 center dot 2MeOH, and 5a center dot 1/2Me(2)CO show an eta(2)-N,C-imine moiety coordinated via the N atom and an orthometallated-C atom. Complex 3, which contains both an orthometallated imine and an eta(1)-imine, is the first structurally characterized hydrido-(eta(1)-imine)-Ir complex. Comparisons are made with data for the corresponding Rh systems.