Mechanism of Dihydrogen Splitting by An Apparent Bimetallic Frustrated Lewis Pair based on Ir(III)/Pt(0)

The incorporation of transition metals into frustrated Lewis pairs (FLPs) offers multiple opportunities for bond activation and catalysis. In this work, we explore the combination acidic Ir(III) cation [(η5-C5Me5)IrCl(PMe2ArDipp2)]+ (ArDipp2=C6H3−2,6-(C6H3−2,6-iPr2)2) with basic Pt(0) compound Pt(PtBu3)2. bulkiness phosphine ligands prevents formation a bimetallic adduct. We have explored cooperative cleavage dihydrogen to gauge FLP reactivity. As anticipated, compounds [(η5-C5Me5)Ir(Cl)(H)(PMe2ArDipp2)] [PtH(PtBu3)2]+ are rapidly formed, which suggests an actual mechanism operating. However, our in-depth experimental/computational study evidences that whole process is considerably more complicated. Instead genuine FLP-type activation, favor synergistic route entails number equilibrium processes Brønsted catalyzed hydrogenation precursor.