Polynuclear copper(II) complexes bridged by polycarboxylates of aromatic and N-heterocyclic compounds

Two categories of polynuclear Cu(II) complexes bridged by multicarboxylate compounds 2,5-pyridine dicarboxylic acid (H2Py2.5-dc), 2,4-pyridine dicarboxylic acid (H-2 py(2,4-dC)), 2 pyrazine dicarboxylic acid (H(2)Pyaz(2.3-dc)) and terephthalic acid (H(2)tp) have been isolated with the tripod N4-donor ligands tris(2-pyridylmethyl)amine (TPA) and tris(2-isopropy1-2-aminoethyl)amine (iptren). The trinuclear bridgedcarboxylato species were obtained with TPA: [(TPA)Cu-(mu(2)-py,2,(4-dc))(2)Cu(H2O)(2)Cu(TPA)1(ClO4)(2).2H(2)O (1), [Cu(TPA)-Cu((TPA)-Cu(mu(2)-Py-2.5dc))(2)-Cu(TPA))(ClO4)(2) (2) and [(TPA)Cu-(mu(2)-Pyaz(2.3-dc))(2)Cu(ClO4)2-Cu(TPA)][C-u(TPA) (H2O)](2)(ClO4)(4).4H(2)O (3), and the dinuclear species [Cu-2(iptren)(2)(tp)](ClO4)(2) (4) and [Cu-2(iptren)2(Pyaz(2.5-dc))1(ClO4)(2).H2O (5) with iptren. The synthesized complexes were characterized by elemental microanalyses, conductivity measurements, IR and UV-Vis spectroscopic techniques as well as by single crystal X-ray crystallography. The nature of polycarboxylate compounds used and the coligands skeletal structure play crucial role in adopting certain carboxylate-bonding mode and the nuclearity of the coordination product. (C) 2016 Elsevier Ltd. All rights reserved.