Iridium-catalyzed dehydrogenation of substituted amine boranes: kinetics, thermodynamics, and implications for hydrogen storage

Dehydrogenation of amine boranes is catalyzed efficiently by the iridium pincer complex (kappa(3)-1,3-((OPBu2)-Bu-t)(2)C6H3)Ir(H)(2) (1). With CH3NH2BH3 (MeAB) and with AB/MeAB mixtures (AB = NH3BH3), the rapid release of 1 equiv of H-2 is observed to yield soluble oligomeric products at rates similar to those previously reported for the dehydrogenation of AB catalyzed by 1. Delta H for the dehydrogenation of AB, MeAB, and AB/MeAB mixtures has been determined by calorimetry. The experimental heats of reaction are compared to results from computational studies.