A series of neutral alkaline earth metal hydride complexes supported by a bulky, unsymmetrical β-diketiminate ligand, [{( Dip/TCHP Nacnac)M(μ-H)} 2 ] (M = Mg, Ca, Sr or Ba).

A bulky, unsymmetrical β-diketiminate ligand, [HC{MeCN(Dip)}{MeCN(TCHP)}] - ( Dip/TCHP Nacnac; 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 PhSiH 3 afforded the first complete series of β-diketiminato heavier group 2 metal hydride complexes, [{( Dip/TCHP Nacnac)M(μ-H)} 2 ] (M = Mg, Ca, Sr or Ba). The unsymmetrical nature of the β-diketiminate ligand seemingly promotes stabilising interactions of ligand Dip groups with the metal centres in the Ca, Sr and Ba hydride complexes.