Synthesis and structural characterization of copper(II), cadmium(II) and zinc(II) complexes with 4,5-diazaspirobifluorene and bis-9-biphenyl-4,5-diazafluorenyl peroxide

The synthesis and structural chemistry of four new divalent transition metal complexes of the fluorene ligands 4,5-diazaspirobifluorene (L1) and bis-9-biphenyl-4,5-diazafluorenyl peroxide (L2), [Cu-3(L1)(4)-(NO3)(6)(H2O)(2)]center dot 2CH(3)CN (1), [Cu(L1)(CH3CO2)(2)(H2O)]center dot 2H(2)O (2), [Cd(L1)(2)(NO3)(2)]center dot DMF (3) (DMF = N,N-dimethylformamide) and [Zn-2(L2)(mu-Cl)(2)Cl-2](infinity) (4) are described. Single-crystal X-ray diffraction analysis reveal that the four complexes exhibit various frameworks due to diverse coordination modes and different conformations of ligands L1 or L2, as well as nitrate, acetate or chloro counterions. L1 in complexes 1, 2 and 3 present an asymmetric rigid bidentate ligand with two nitrogen atoms as the donor sites. Novel complex 4 was formed through complexation between conformationally bent shaped peroxide ligands and zinc(II) dichlorides that adopt a linear coordination geometry, which can also give rise to extended polymeric chains with a zigzag secondary structure. (C) 2008 Elsevier Ltd. All rights reserved.