Exploring the Limits of Catalytic Ammonia–BoraneDehydrogenation Using a Bis(N-heterocyclic carbene) Iridium(III) Complex.

Ammoniaborane dehydrogenation can be catalyzed by a number of organometallicspecies. [Ir(κ2-ItBu)2][PF6] (ItBu = 1,3-bis(tert-butyl)imidazol-2-ylidene) is the most active catalystfor this process that has been reported to date. We explore hereinthe absolute limits of the use of this and related complexes, including[Ir(κ2-ItBu)2][BArF4], [Ir(H)2(ItBu)2][BArF4], and[Ir(κ2-ItBu)2(NH3)][BArF4] (BArF4= tetrakis(3,5-bis(trifluoromethyl)phenyl)borate). [ABSTRACT FROM AUTHOR]