title: Dicopper(II) Complexes of the Antitumor Analogues Acylbis(salicylaldehyde hydrazones) and Crystal Structures of Monomeric [Cu(2)(1,3-propanedioyl bis(salicylaldehyde hydrazone))(H(2)O)(2)].(ClO(4))(2).3H(2)O and Polymeric [{Cu(2)(1,6-hexanedioyl bis(salicylaldehyde hydrazone))(C(2)H(5)OH)(2)}(m)()].(ClO(4))(2)(m)().m(C(2)H(5)OH).
abstract: Salicylaldehyde hydrazones derived from acyldicarboxylic acids (H(4)L(n)(), where n = 0, 1, 2, 4, 6, 8, 10, 14 and is the number of methylene units) of varying chain length have been prepared, and their dicopper(II) complexes have been isolated as bis analogues of antitumor carboxylate hydrazones. The predominant structural form adopted is polymeric, with [{Cu(2)L(n)()}(m)()] formed in neutral or basic solution, [{Cu(2)(H(2)L(n)())Cl(2)}(m)()] from dilute HCl, and [{Cu(2)(H(2)L(n)())}(m)()].(ClO(4))(2)(m)() from dilute HClO(4). The crystal structures of [Cu(2)(H(2)L(1))(H(2)O)(2)].(ClO(4))(2).3H(2)O and [{Cu(2)(H(2)L(4))(C(2)H(5)OH)(2)}(m)()].(ClO(4))(2)(m)().m(C(2)H(5)OH) have been determined. The structure of [Cu(2)(H(2)L(1))(H(2)O)(2)]. (ClO(4))(2).3H(2)O consists of discrete di-Cu(II) molecules with nonsymmetry-related Cu(II) centers. The copper atoms are square-planar with H(2)L(1) supplying two tridentate, monoanionic ONO domains and water completing the coordination sphere. The two metal-binding domains are inclined at 80 degrees to each other. For [{Cu(2)(H(2)L(4))(C(2)H(5)OH)(2)}(m)()].(ClO(4))(2)(m)().m(C(2)H(5)OH) the symmetry-related copper atoms are square-pyramidal with the base composed of H(2)L(4), acting as a tridentate ONO chelator, and an O-bonded ethanol molecule. Axial phenolato bridges complete the coordination sphere, linking molecules to give a polymer. Compounds prepared have been characterized by a range of physicochemical and spectroscopic techniques, and proton and metal ion stability constant data have been determined.
authors.affiliation: Department of Chemistry, National University of Singapore, Lower Kent Ridge Road, Singapore 119260.
authors.forename: John D.
authors.initials: JD
authors.lastname: Ranford
authors.forename: Jagadese J.
authors.initials: JJ
authors.lastname: Vittal
authors.forename: Yu M.
authors.initials: YM
authors.lastname: Wang