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[OC(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.