Ligand effects in the syntheses of molecular main group metal species containing interstitial hydride

In seeking to investigate whether structures of the type observed for {[Me3 Al(TMP)]Li}(infinity). (TMP = 2,2,6,6-tetramethylpiperidide) can be oligome rised by the use of polyfunctional N-centred ligands, we report lithium alu minates incorporating RN -C(H)- NR residues. For PhN -C(Ph)- NPh =Am cluste r cation-containing (Li4Am3)(+). {Li[(mu -Me)(2)Al(Me)Bu-t](2)](-) is affor ded. However, the empolyment of PhN(H)(2-pyr) (pyr = pyridyl) instead affor ds both [Li-8(H)[N(2-pyr)Ph](6)}(+). [Li(Me2AlBu2t)(2)](-) and Li-7(H)[N(2- pyr)Ph](6): the first molecular Main Group clusters to incorporate intersti tial hydride. Results indicate that R-elimination front (BuLi)-Li-t represe nts the source of H-. in these reactions.