SYNTHESIS, STRUCTURE, AND PYROLYSIS OF ORGANOALUMINUM AMIDES DERIVED FROM THE REACTIONS OF TRIALKYLALUMINUM COMPOUNDS WITH ETHYLENEDIAMINE IN A 3-2 RATIO

The reactions of triethylaluminum and trimethylaluminum with ethylenediamine (en) in a 3:2 ratio have been studied. Heating of the initially formed (R3Al)2.en and R3Al.en adduct mixture results in the formation of RAl[(HN(CH2)2NH)AIR2]2 (R = CH3 [3] and C2H5 [4]). The structures and formation mechanisms of these two compounds, as well as their pyrolysis reactions, have been studied with H-1, C-13, and Al-27 NMR, FTIR, MS, GC, DSC, and TGA techniques. The methyl derivative (3) was characterized by a single-crystal X-ray diffraction analysis: space group P2@c; a = 15.523 (3) angstrom; b = 8.419 (1) angstrom; c = 13.464 (3) angstrom; V = 1663.8 (5) angstrom-3; beta = 109.00 (2)-degrees; Z = 4. Full-matrix least-squares refinement converges as R = 0.051 and R(w) = 0.076 based on 2280 reflections with F > 4-sigma-(F). Both four- and five-coordinated Al atoms were observed in which the en-2H groups serve as both chelating and bridging ligands.