Scheme 1. The preparation of iridium catalysts 1 containing imine–diphosphine ligands and the X-ray structure of complex B. The H atoms, except for the hydride ligands, and disorder were omitted for clarity. Thermal ellipsoids shown at the 30% probability level. Selected bond lengths [Å] and angles [°] for complex B: Ir1–P1a 2.319 (2), Ir1–N1 2.115(7), Ir1–Cl1 2.391(3), Ir1–Cl2 2.579(3); P1a–Ir1–N1 91.59(4), P1a–Ir1–P1 174.90(9), N1–Ir1–Cl2 82.5(2), N1–Ir1–Cl1 177.3(2).
