Characterization of a Rhodium(III)−Imine−Orthometalated Imine Complex: Reversible C−H Activation of a Coordinated Imine

Solutions of cis -[Rh(PPh 3 ) 2 (solv) 2 ]PF 6 (solv = acetone or MeOH) react at room temperature under Ar with benzophenone imine to yield cis -[Rh(PPh 3 ) 2 (η 1 -NH CPh 2 ) 2 ]PF 6 ( 3 ), but depending on reaction conditions, one of the imine ligands undergoes orthometalation to give [RhH{NH C(Ph)( o- C 6 H 4 )}(HN CPh 2 )(PPh 3 ) 2 ]PF 6 ( 2 ) with trans -phosphines; this is the first recorded complex containing an imine in its η 1 -form and as an η 2 -moiety formed via orthometalation. Complexes 2 and 3 are characterized by elemental analysis, 1 H and 31 P{ 1 H} NMR spectroscopy, and, in the case of 2, an X-ray crystal structure.