Square Planar Ru( i Pr 2 PCH 2 CH 2 NH) 2 and its Role in Fast and Selective Catalytic Amine–Borane Dehydropolymerization to Form High Molecular Weight Polyaminoboranes

Abstract Addition of t BuOK to orange RuCl 2 ( i Pr 2 PCH 2 CH 2 NH 2 ) 2 forms the pink, square planar, Ru(II) complex Ru( i Pr 2 PCH 2 CH 2 NH) 2 . This is an active catalyst (ToF 250 s −1 ) for the dehydropolymerization of H 3 B·NMeH 2 to give high molecular weight polyaminoborane, [H 2 BNMeH] n ( M n  = 138 700 g mol −1 ) at low loadings (0.03 mol%). An induction period observed is due to the initial formation of a hydroxy‐hydride species, Ru( i Pr 2 PCH 2 CH 2 NH 2 ) 2 (OH)(H), prior to fast turnover.