Triesters of phosphoric acid OP(OR)(3) (R = Me, Et, n-Bu, SiMe3) react with [M(NMe2)(3)](2) (M = Al (B), Ga (2)) in nonaqueous aprotic solvents with the formation of amorphous alumino-and gallophosphates MPO4 (M = Al, Ga). Triphenyl phosphate, on the other hand, undergoes ligand scrambling with 1 and 2. Aluminophosphate also results from the reaction of AlCl3 with OP(OSiMe3)(3). The products and mechanisms of these reactions were examined by H-1, C-13, Si-29, and (31)p NMR spectroscopy, X-ray powder diffraction (XRD), thermogravimetric methods (TG/DTA), infrared spectroscopy (LR), and elemental analyses. The molecular structure of the first-step model compound (Me2N)(3)Al . OPPh3 (3) was established by the single-crystal X-ray diffraction experiment. Crystal data for 3 (-70 degrees C) : a = 8.870(2) Angstrom, b = 10.195(3) Angstrom, c = 14.706(5) Angstrom, alpha = 90.27(3)degrees, beta = 94.04(2)degrees, gamma 109.61(2)degrees V = 1249.0(6) Angstrom(3), Z = 2, triclinic space group (No. 2). Alumazene [MeAINDipp](3) (4) forms a bis-adduct [MeAINDipp](3) . 2OP(OMe)(3) (5) with trimethyl phosphate. The molecular structure of 5 was also elucidated by X-ray crystallography. Crystal data for 5 (-140 degrees C) : a = 12.176(2) Angstrom, b = 12.630(3) Angstrom, c = 21.376(4) Angstrom, alpha = 96.04(3)degrees, beta = 90.46(3)degrees, gamma = 115.38(3)degrees V = 2948(1) Angstrom(3), Z = 2, triclinic space group (No. 2).