Alkylmagnesium complexes with the rigid dpp-bian ligand {dpp-bian 1,2-bis[(2,6-diisopropylphenyl)imino]acenaphthene}

The reactions between equimolar amounts of (dpp-bian)Na(Et2O)(x) (1) {dpp-bian = 1,2-bis[(2,6-diisopropylphenyl)imino]acenaphthene}and MeMgBr, EtMgBr and Me3SiCH2MgCl in Et2O afford the corresponding alkylmagnesium complexes [(dpp-bian)MgMe](2) (2), (dpp-bian)MgEt(Et2O) (3) and (dpp-bian)MgCH2SiMe3(Et2O) (4), respectively. Compound 2 and tBuOH react with elimination of methane and the formation of [(dpp-bian)MgOtBu](2) (5). Compounds 2-5, all of which contain the dpp-bian ligand in its radical monoanionic form, were characterised by elemental analysis, IR spectroscopy, as well as by single-crystal X-ray diffraction. Molecular structure determination revealed that the magnesium atoms in 25 are four-coordinate. The magnesium atoms of complexes 2 and 5 reach the coordination number four by dimerisation through bridging Me and tBuO groups, respectively, whereas compounds 3 and 4 reach it by coordination of one molecule of diethyl ether. (C) Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2008).