Abstract
Reaction of dibenzyl calcium complex [Ca(Me4TACD)(CH2Ph)2], containing the neutral NNNN-type macrocyclic ligand Me4TACD (Me4TACD=1,4,7,10-tetramethyl-1,4,7,10-tetraazacyclododecane), with triphenylsilane gave the cationic dinuclear calcium hydride [Ca2H2(Me4TACD)2](PhCHSiPh3)2 which was characterized by NMR spectroscopy and single-crystal X-ray diffraction.
The cation can be regarded as the ligand-stabilized dimeric form of hypothetical [CaH]+. Hydrogenolysis of benzyl calcium cation [Ca(Me4TACD)(CH2Ph)(thf)]+ gave dicationic calcium hydrides [Ca2H2(Me4TACD)2][BAr4]2 (Ar=C6H4-4-tBu; C6H3-3,5-Me2) containing weakly coordinating anions.
In THF, they catalyzed the isotope exchange of H2 and D2 to give HD and the hydrogenation of unactivated 1-alkenes.