Nature of the reactants and influence of water on the supramolecular assembly

Abstract

The influences of the nature of reactants and water on the self-assembly of cationic Cu(II) complex structures containing N-(2-pyridylmethyl)glycine (Hpgly) and N-(2-pyridylmethyl)-L-alanine (Hpala) ligands have been investigated. A metallamacrocycle [Cu6(pgly)3(spgly) 3] (ClO4)6·9H2O has been formed by the reaction of [Cu(pgly)2]·2H2O with Cu(ClO4)2·6H2O. The hexameric cation has Schiff base and reduced Schiff base ligands alternatively bonded to Cu(II) to provide cyclohexane-like conformation with a cavity diameter of 9.4 Å. The reaction of Cu(ClO4)2·6H2O with Hpgly-HCl yielded [Cu(pgly)(H2O)](ClO4), which is presumed to have 1D coordination polymeric structure. A {K⊂[12-MC-3]} metallacrown, [K(ClO4)3{Cu3(pala) 3}](ClO4) has been isolated by reacting Cu(ClO 4)2 with Kpala in MeCN/MeOH. This {K⊂[12-MC-3]} metallacrown further reacts with water to form an infinite 1D coordination polymer [Cu(pala)(H2O)(ClO4)]n, which can also be obtained by conducting the reaction in aqueous MeOH.