Flash Communication: Ir Complexes with a PhN(CH2CH2PiPr2)2 Pincer Ligand for Reversible CO2 Hydrogenation

Abstract

The pincer ligand PhN(CH2CH2PiPr2)2 (iPrPNPhP) was treated with [Ir(coe)2(μ-Cl)]2 (coe = cyclooctene) under H2 to generate (iPrPNPhP)IrH2Cl (1). Reaction of 1 with LiBHEt3 formed (iPrPNPhP)IrH3 (2). The solid-state structures of 1 and 2 were determined. Compound 2 catalyzes CO2 hydrogenation to formate and formic acid dehydrogenation but gives inferior performance to systems with RN(CH2CH2PiPr2)2 (R = H or Me) ligands, demonstrating the importance of the substituent on the nitrogen donor.