Hydrogen elimination in bulky calcium amidoborane complexes: isolation of a calcium borylamide complex.

The decomposition route of N-substituted calcium amidoborane complexes depends on the steric bulk of the substituent. Relatively small substituents (R = H, Me, iPr) gave dehydrogenation to dimeric complexes with a bridging RN-BH-N(R)-BH(3)(2-) ion, whereas the larger 2,6-di-isopropylphenyl substituent resulted in formation of a complex with a borylamide anion: H(2)B(R)N(-). This product is a promising species for (catalytic) regeneration with H(2), i.e., hydrogenation to the amidoborane anion H(3)B(R)NH(-).