title: Herbicides interacting with lanthanide(III) and calcium(II) ions: structural and biological similarities of Gd and Ca polymers.
abstract: In this paper we report the synthesis and characterization of Ca(II), Gd(III) and Ce(III) complexes with chlorophenoxyalkanoic acids, which are commonly used as herbicides. The Gd(III) and Ca(II) complexes were characterized by the typical formulas [Gd(III)(L)(3)(H(2)O)(2).2dmf](n) and [Ca(L)(2)(MeOH)(2)](n) [L=[2,4-D=2,4-dichlorophenoxyacetic acid, 2,4,5-T=2,4,5-trichlorophenoxyacetic acid, MCPA=2-methyl-4-chlorophenoxy acetic acid and 2,4-DP=2-(2,4-dichlorophenoxy)propanoic acid]]. The crystal structure of the Gd(III) complex with 2,4-D shows that the compound is a one-dimensional polymer with a [Gd(III)(2)(2,4-D)(6)(H(2)O)(4)] dimeric repeat unit and the gadolinium atoms are in a nine-coordination environment, while the crystal structure of the Ca analog shows that it also has a polymeric structure with a [Ca(2)(2,4-D)(4)(CH(3)OH)(4)] dimeric repeat unit and the calcium atoms are in an eight-coordination environment. The gadolinium compound displays three different coordination modes for the carboxylato moiety, bidentate chelate, bidentate double bound and bidentate triple bound, while the calcium compound displays only one, bidentate triple bound. Coordination spheres are completed with oxygens of H(2)O or MeOH molecules, respectively. The complexes were tested against a few common bacteria by minimum inhibitory concentration (MIC) experiments and did not exhibit any antimicrobial action at concentrations up to 1600 microg/ml.
authors.affiliation: Department of General and Inorganic Chemistry, Faculty of Chemistry, Aristotle University of Thessaloniki, 54006, Thessaloniki, Greece.
authors.forename: Catherine
authors.initials: C
authors.lastname: Dendrinou-Samara
authors.forename: Dimitra
authors.initials: D
authors.lastname: Drosou
authors.forename: Lykourgos
authors.initials: L
authors.lastname: Iordanidis
authors.forename: Aris
authors.initials: A
authors.lastname: Terzis
authors.forename: Dimitris P
authors.initials: DP
authors.lastname: Kessissoglou
mesh_terms: D000900:Anti-Bacterial Agents / Q000138:chemical synthesis* / Q000494:pharmacology; D001419:Bacteria / Q000187:drug effects; D002118:Calcium / Q000737:chemistry*; D018360:Crystallography, X-Ray; D006540:Herbicides / Q000737:chemistry*; D028581:Lanthanoid Series Elements / Q000737:chemistry*; D008826:Microbial Sensitivity Tests; D015394:Molecular Structure; D009942:Organometallic Compounds / Q000138:chemical synthesis / Q000494:pharmacology*
chemical_list: D000900:Anti-Bacterial Agents; D006540:Herbicides; D028581:Lanthanoid Series Elements; D009942:Organometallic Compounds; D002118:Calcium