Coordination chemistry of 1,4-bis[bis(2-pyridylmethyl)aminomethyl]benzene with copper(II)

The interaction of 1,4-bis[bis(2-pyridylmethyl)aminomethyl]benzene (p-Xy(DPA)) with CuCl2 center dot 2H(2)O has resulted in the isolation of the dinuclear compound [Cu-2(p-Xy(DPA))Cl-4]center dot H2O (1). When the reaction was performed in presence of sodium perchlorate, sodium azide, sodium dicyanamide (Nadca) and disodium squarate (Na2C4O4) the compounds [Cu-2(p-Xy(DPA))(ClO4)(2)Cl-2] (2), [Cu-2(p-XYDPA)(N-3)(4)]center dot 2H(2)O (3), [Cu-2(p-Xy(DPA))(dca)(4)]center dot 4H(2)O (4), and [Cu-2(p-Xy(DPA))Cl-2(H2O)(2)](C4O4)center dot 5.4H(2)O (5) were obtained, respectively. The complexes were characterized by IR and UV-vis. spectroscopy. The visible spectra of the complexes revealed the square pyramidal geometry around the central Cu2+ ions. The molecular structures of the complexes 2, 3, 4 and 5 were determined by single crystal X-ray crystallography. This study revealed the dinuclear nature of the complexes and showed that the Cu(II) centers have distorted five-coordinate square pyramidal geometry with N-3-donor atoms of the dipicolyl amine arms and the remaining coordination positions are occupied by the chloro and perchlorato ligands in 2, the monodentate azido ligands in 3 or the monodentate terminal nitrile dca in 4 and by the chloro and aqua ligands in 5 with the squarate dianion as counter ion. (C) 2011 Elsevier B.V. All rights reserved.