NMR, X-RAY AND MASS SPECTROMETRY CHARACTERIZATION OF SOME HETEROLEPTIC ALUMINUM ALKOXIDE COMPLEXES

摘要

Among the synthesized (CH_3)_2AlOR compounds (R = CH_2CH_2OCH_3 (1), CH(CH_3)CH_2OCH_3 (2), CH_2CH_2OCH(CH_3)_2 (3), CH(CH_3)CH_2OC(CH_3)_3 (4)), 2 and 4 have been characterized by ~1H and ~(27)Al NMR spectroscopy and X-ray diffraction, while 1, 2 and 3 have been studied by mass spectrometry using an instrument with a specially designed input system to obtain data on heterogeneous thermal decomposition. While in the solid state, it is clear that the compounds are present in the form of an oxygen-bridged dimer with a five-coordinated aluminum center, in solution an equilibrium exists between two fluxional species containing tetra- and penta- coordinated Al atoms respectively.