Copper(II) complexes with phenoxyalkanoic acids and nitrogen donor heterocyclic ligands: structure and bioactivity

The copper complexes with the phenoxyalkanoic acids MCPA, 2,4-D, 2,45-T and 2,4-DP in the presence of a nitrogen donor heterocyclic ligand, phen or bipyam, were prepared and characterized. Interaction of Cu(II) with phenoxyalkanoic acids and bipyam leads to dinuclear or uninuclear neutral complexes while in the presence of phen uninuclear neutral or cationic forms have been isolated. The crystal structure of bis(1,10-phenanthroline)(2-methyl-4-chloro-phenoxyacetato)copper(II) chloride-methanol(1/1)-water(1/0.6), 1 has been determined and refined by least-squares methods using three-dimensional MoKalpha data. 1 crystallizes in space group P (1) over bar, in a cell of dimensions a = 14.577(6)Angstrom, b = 11.665(5) Angstrom, c = 12.249(6) Angstrom, alpha = 98.38(1)degrees, beta = 112.18(1)degrees gamma = 104.56(1)degrees, V = 1798(1) Angstrom (3) and Z = 2. The cyclic voltammograms of uninuclear cationic complexes in dmf exhibit an extra cathodic wave due to the chloride ion. The available evidence supports an increasing antimicrobial effeciency for the cationic complexes. (C) 2001 Elsevier Science B.V. All lights reserved.