Allosteric-controlled metal specificity of a ditopic ligand

Abstract

(Chemical Equation Presented) To twist or not to twist? A ditopic ligand, L1, that contains a potentially tetradentate pyridyl-thiazole ligand chain and a "external" crown ether unit is presented. Reaction of L1 with Cu+ or Zn2+ ions results in the formation of a dinuclear double helicate [Cu2(L1) 2]2+ or a mononuclear [ZnL1]2+ species. This ditopic system changes its preference for Cu+ or Zn2+ ions on the inclusion of s-block-metal ions at the crown ether binding site (e.g., Sr2+ ions as shown in the scheme). © 2005 Wiley-VCH Verlag GmbH & Co. KGaA.