Monomeric Alkylaluminum Complexes (dpp-BIAN)AlR2 (R = Me, Et, iBu) Supported by the Rigid Chelating Radical-Anionic 1,2-Bis[(2,6-diisopropylphenyl)imino]acenaphthene Ligand (dpp-BIAN)

Me 2 AlCl, Et 2 AlBr, and i Bu 2 AlCl react with (dpp-BIAN)Na (dpp-BIAN = 1,2-bis[(2,6-diisopropylphenyl)imino]acenaphthene) in Et 2 O to give the dialkylaluminum complexes (dpp-BIAN)AlR 2 (R = Me ( 1 ), Et ( 2 ), i Bu ( 3 )). Compounds 1 − 3 have been characterized by elemental analysis, IR and ESR spectroscopy, and X-ray crystal structure analysis. In the molecules of 1 − 3 the Al atoms are tetrahedrally coordinated by two alkyl groups and the two N atoms of the dpp-BIAN ligand. The ESR spectra of the complexes prove the radical character of the dpp-BIAN ligand and show a hyperfine structure due to the coupling of the unpaired electron with the 14 N, 27 Al, and 1 H nuclei.