A Series of Neutral Alkaline Earth Metal Hydride Complexes Supported by a Bulky, Unsymmetrical B-Diketiminate Ligand, [{(Dip/TCHPNacnac)M(mu-H)}2] (M = Mg, Ca, Sr or Ba)

A bulky, unsymmetrical B-diketiminate ligand, [HC{MeCN(Dip)}{MeCN(TCHP)}]- (Dip/TCHPNacnac; Dip = 2,6-diisopropylphenyl, TCHP = 2,4,6-tricyclohexylphenyl), has been utilised in the preparation of a series of magnesium alkyl and calcium, strontium and barium amide complexes. Reaction of these with PhSiH3 afforded the first complete series of B-diketiminato heavier group 2 metal hydride complexes, [{(Dip/TCHPNacnac)M(mu-H)}2] (M = Mg, Ca, Sr or Ba). The unsymmetrical nature of the B-diketiminate ligand seemingly promotes stabilising interactions of ligand Dip groups with the metal centres in the Ca, Sr and Ba hydride complexes.