Reaction of dibenzyl calcium complex [Ca(Me TACD)(CH Ph) ], containing the neutral NNNN-type macrocyclic ligand Me TACD (Me TACD=1,4,7,10-tetramethyl-1,4,7,10-tetraazacyclododecane), with triphenylsilane gave the cationic dinuclear calcium hydride [Ca H (Me TACD) ](PhCHSiPh ) 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(Me TACD)(CH Ph)(thf)] gave dicationic calcium hydrides [Ca H (Me TACD) ][BAr ] (Ar=C H -4- Bu; C H -3,5-Me ) containing weakly coordinating anions. In THF, they catalyzed the isotope exchange of H and D to give HD and the hydrogenation of unactivated 1-alkenes.

Die Reaktion des Dibenzylcalcium-Komplexes [Ca-(Me 4 TACD)(CH 2 Ph) 2 ], stabilisiert durchd en neutralen, makrocyclischen Liganden 1,4,7,10-Tetramethyl-1,4,7,10-tetra