Monomeric magnesium and calcium complexes containing the rigid, dianionic 1,2-bis[(2,5-di-tert-butylphenyl)imino]acenaphthene (dtb-BIAN) and 1,2-bis[(2-biphenyl)imino]acenaphthene (bph-BIAN) ligands

The new rigid bidentate nitrogen ligands 1,2-bis[(2,5-di-tert-butylphenyl)imino]acenaphthene (1) (dtb-BIAN) and 1,2-bis[(2-biphenyl)imino]acenaphthene (2) (bph-BIAN) have been synthesized by condensation of 1,2-acenaphthylenedione with 2,5-di-tert-butylaniline and 2-aminobiphenyl, respectively. Reduction of 1 and 2 with magnesium and calcium results in the formation of the monomeric metal complexes [(dtb-BIAN)Mg(THF)(2)] (3), [(bph- BIAN)Mg(DME)(2)] (4), and [(bph-BIAN)Ca(THF)(3)] (5). Compounds 1 - 5 have been characterized by C/H analyses, IR, H-1 NMR, and C-13 NMR spectra, the structures of 2, 3, and 5 have been estimated by single crystal X-ray diffraction.