Synthesis, characterization and crystal structures of copper(II) complexescontaining multidentate polypyridine ligands

Three mononuclear copper(II) complexes of the tetrapyridyl ligand bis[di(2- pyridyl)methyl]amine have been synthesised and crystallized. The correspond ing X-ray crystal structures displayed different geometries around the meta l ion, which are mainly induced by the nature of the anionic ligands of the copper(II) salt. Cu(BDPMA)Cl-2 1, Cu(BDPMA)(SO4)MeOH 2 and [Cu(BDPMA)(BF4) CH3CN]BF4 3 exhibited distorted trigonal bipyramidal, square pyramidal and octahedral geometries, respectively. FAB mass spectra and ESR spectra of cr ystalline samples and frozen solutions suggested that the overall structure s are not modified for complexes 1-3 on going from the solid to the solutio n states.