Interrogating the steric outcome during H2 heterolysis: in-plane steric effects in the regioselective protonation of the PN3P-pincer ligand.

H2 heterolysis to generate well-defined nickel hydride-proton complexes was achieved by the 2nd generation PN3P-pincer nickel platform. The regioselective protonation in the ligand framework was demonstrated for the first time to highlight the importance of in-plane hindrance during the H2 splitting process.