Imido analogs of aluminophosphates: syntheses and X-ray structures of {LiAl[OP(NtBu)2(NHtBu)]2}2 and the mono- and di-methylaluminum complexes of the anions [OP(NtBu)x(NHtBu)3−x]x− (x=1, 2)

The reaction of OP(NHtBu)3 with trimethylaluminum in 1:1 or 2:1 molar ratios in hydrocarbon solvents yields the complexes {Me2Al(μ-NtBu)2P(μ-O)(NHtBu)AlMe2[OP(NHtBu)3]} (1) and MeAl[(μ-NtBu)(μ-O)P(NHtBu)2]2 (2). The dimeric complex {LiAl[OP(NtBu)2(NHtBu)]2}2 (3) is obtained by treatment of OP(NHtBu)3 with LiAlH4 in toluene. Complexes 1–3 were characterized by multinuclear NMR spectroscopy and by X-ray crystallography, which revealed different bonding modes for the anions [OP(NtBu)(NHtBu)2]2− and [OP(NtBu)2(NHtBu)]2−.