Self-activated DNA cleavage and nitric oxide reactivity studies on mononuclear copper complexes derived from tetradentate ligands

Two new tetradentate ligands Timpy (1,2-bis((E)-(2-phenyl-2-(pyridine-2-yl)hydrozono)methyl)benzene) and Gimpy ((1Z,2Z)-1,2-bis(2-phenyl-2-(pyridine-2-yl)hydrozono)ethane) were synthesized and characterized. Mononuclear complexes [Cu(Timpy)(ClO4)](ClO4) (1) and [Cu(Gimpy)](ClO4)2 (2) were synthesized and characterized by IR, UV–visible and conductivity measurements. The molecular structure of [Cu(Timpy)(ClO4)](ClO4) (1) was determined by single crystal X-ray diffraction and structural index parameter (τ = 0.4725) supported distorted square planar geometry at the metal centre. Electrochemical studies for 1 and 2 were investigated. Two-fold applications of these complexes were examined. First, self-activated DNA cleavage activity of complexes 1 and 2 and mechanism of nuclease activity. Second, the complexes were utilized as fluorescence probe for the detection of nitric oxide in solution.

Mononuclear copper(II) complexes [Cu(Timpy)(ClO4)](ClO4) (1) and [Cu(Gimpy)](ClO4)2 (2) derived from tetradentate ligands Timpy and Gimpy. Two-fold applications of these complexes will be described. First, these complexes were efficient in cleaving DNA in self-activated pathway and enhancement of nuclease activity was observed in presence of oxidizing or reducing agent. Second, the complexes were utilized as fluorescence probe for the detection of nitric oxide.Figure optionsDownload as PowerPoint slideHighlights
► Copper complexes derived from tetradentate ligands were synthesized.
► Ligands and complexes were characterized by spectroscopic studies.
► Molecular structure of representative complex was determined by X-ray crystallography.
► Nuclease activity happened via self-activation.
► Nitric oxide detection in solution by fluorescence measurement.