title: Molybdenum catalyzed ammonia borane dehydrogenation: oxidation state specific mechanisms.
abstract: Though numerous catalysts for the dehydrogenation of ammonia borane (AB) are known, those that release >2 equiv of H2 are uncommon. Herein, we report the synthesis of Mo complexes supported by a para-terphenyl diphosphine ligand, 1, displaying metal-arene interactions. Both a Mo(0) N2 complex, 5, and a Mo(II) bis(acetonitrile) complex, 4, exhibit high levels of AB dehydrogenation, releasing over 2.0 equiv of H2. The reaction rate, extent of dehydrogenation, and reaction mechanism vary as a function of the precatalyst oxidation state. Several Mo hydrides (Mo(II)(H)2, [Mo(II)(H)](+), and [Mo(IV)(H)3](+)) relevant to AB chemistry were characterized.
authors.affiliation: Division of Chemistry and Chemical Engineering, California Institute of Technology , 1200 East California Boulevard, MC 127-72, Pasadena, California 91125, United States.
authors.forename: Joshua A
authors.initials: JA
authors.lastname: Buss
authors.forename: Guy A
authors.initials: GA
authors.lastname: Edouard
authors.forename: Christine
authors.initials: C
authors.lastname: Cheng
authors.forename: Jade
authors.initials: J
authors.lastname: Shi
authors.forename: Theodor
authors.initials: T
authors.lastname: Agapie