Synthesis, characterisation and molecular recognition of novel Zn(II) macrocyclic complexes with imidazole or benzimidazole pendants

Macrocyclic polyamine Zn(II) mononuclear and dinuclear complexes bearing imidazole or benzimidazole pendants have been synthesised and their binding constants determined by UV-Vis spectrometric titration. The binding ability of the complexes is stronger than that of the control materials with cytosine (Cyt). The recognition abilities of the dinuclear complexes for Cyt are much higher than that for the other bases or nucleosides (such as uracil, 5-hydroxymeyhyl uracil, adenosine, thymidine and uridine); the binding constants of the dinuclear complexes with m-xylyl or pyridyl as linkers are 25,360 and 22,550 dm(3) mol(-1) respectively.