Synthesis and structural characterization of magnesium complexes bearing phenanthrene imine derivative ligands

Reduction reactions of the phenanthrene-o-aryliminoquinone with 0.5 equiv of magnesium in tetrahydrofuran afford the bisligated magnesium complexes [(Ar)piq](2)Mg(thf) (1a, Ar = 2,6-Me2C6H3; 1b, Ar = 2,6-(Pr2C6H3)-Pr-i). 1a can be further reduced by magnesium to oxygen-bridged dinuclear complex [(mu-O)(Ar-)piqMg(thf)(2)](2) (2). Similar reduction reactions of the N,N-bis(arylimino)phenanthrene with magnesium give bis(arylimino)phenanthrene magnesium complexes (Ar1,Ar2)bipMg(thf)(3) (3, Ar-1 = Ar-2 = 2,6-Me2C6H3: 4, Ar-1 = Ar-2 = 2,6-(Pr2C6H3)-Pr-i: 5, Ar-1 = 2,6-Me2C6H3, Ar-2 = 2,6-(Pr2C6H3)-Pr-i). All the complexes were well characterized and the molecular structures of 1b, 2, 3, and 5 were established by X-ray diffraction analysis. (C) 2013 Elsevier Ltd. All rights reserved.