Unexpected reactivity of an alkylaluminum complex of a non-innocent 1,2-bis[(2,6-diisopropylphenyl)imino]acenaphthene ligand (dpp-bian)

Abstract

The reaction of (dpp-bian)AlEt(Et2O) (1) (dpp-bian = 1,2-bis[(2,6-diisopropylphenyl)imino]acenaphthene) with 4,4'-dimethoxybenzophenone leads to the replacement of Et2O with the ketone resulting complex (dpp-bian)AlEt[O[double bond, length as m-dash]C(4-MeOC6H4)2] (2). The reaction of compound 1 with 2,6-di-tert-butyl-4-methylphenol (1 : 1) or Ph2NH (1 : 1) affords the addition products [dpp-bian(H)]AlEt[O(2,6-tBu2-4-MeC6H2)] (3) and [dpp-bian(H)]AlEt(NPh2) (4) correspondingly. Treatment of complex 1 with 0.5 molar equivalents of H2O gives ethylalumoxane {[dpp-bian(H)]AlEt}2(μ-O) (5). Newly prepared complexes 2-5 have been characterized by NMR and IR spectroscopy, and the molecular structures of 2, 3, and 5 have been determined by single crystal X-ray analysis.