The simplest amino‐borane H2B=NH2 trapped on a rhodium dimer : pre‐catalysts for amine–borane dehydropolymerization

Abstract

The μ‐amino–borane complexes [Rh2(LR)2(μ‐H)(μ‐H2B=NHR′)][BArF4] (LR=R2P(CH2)3PR2; R=Ph, iPr; R′=H, Me) form by addition of H3B⋅NMeR′H2 to [Rh(LR)(η6‐C6H5F)][BArF4]. DFT calculations demonstrate that the amino–borane interacts with the Rh centers through strong Rh‐H and Rh‐B interactions. Mechanistic investigations show that these dimers can form by a boronium‐mediated route, and are pre‐catalysts for amine‐borane dehydropolymerization, suggesting a possible role for bimetallic motifs in catalysis