Synthesis, Spectroscopic, and Electrochemical Studies on Some New Copper(II) Complexes Containing 2-{[(Z)-Phenyl (Pyridine-2-yl) Methylidene] Amino}Benzenethiol and Monodentate Ligands

Abstract

Five new mononuclear copper(II) complexes, namely, [Cu(L)(ImH)]·ClO41; [Cu(L)(Me-ImH)]·ClO42; [Cu(L)(Et-ImH)]·ClO43; [Cu(L)(2-benz-ImH)]·ClO44; [Cu(L)(benz-ImH)]·ClO45, where HL = 2-{[(Z)-phenyl (pyridine-2-yl) methylidene] amino} benzenethiol; ImH = Imidazole; Me-ImH = Methy-limidazole; Et-ImH = Ethyl-imidazole; 2-benz-ImH = 2-methyl-benzimidazole; benz-ImH = benz-imidazole, have been synthesized and characterized by various physicochemical and spectroscopic techniques. Magnetic moments, electronic spectra, and EPR spectra of the complexes suggested a square planar geometry around Cu(II) ion. The synthesized HL ligand behaves as monobasic tridentate Schiff base bound with the metal ion in a tridentate manner, with N2S donor sites of the pyridine-N, azomethine-N, and benzenethiol-S atoms. The redox behaviour of the copper complexes has been studied by cyclic voltammetry. Superoxide dismutase activity of these complexes has been revealed to catalyse the dismutation of superoxide (O2-) and IC50 values were evaluated and discussed.

Understanding the Effect of Functional Groups on the Seeded Growth of Copper on Carbon Nanotubes for Optimizing Electrical Transmission

“…[23][24][25][26][27] Of these substituents, pyridine functionality not only acts as an efficient ligand, 24,28,29 but also facilitates a decrease in the copper reduction potential, resulting in the preferential reduction of the surface bound Cu(II) to Cu(I). [29][30][31][32][33][34][35] This coordinated Cu can then act as a catalyst for the deposition of further Cu(II) ions from solution, allowing controlled seeded growth by electroless deposition. 28,29,36 In the case of CNTs, we have reported that pyridine (py) functionalization may be achieved through 1,3-dicyclohexylcarbodiimide (DCC) coupling of isonicotinic acid (with CNT-OH groups) or 4-hydroxypyridine (with CNT-CO 2 H groups).…”

“…A commonly used approach to facilitate the deposition of Cu nanoparticles on CNTs is through oxidation of the CNTs to graft epoxide, hydroxyl, and carboxyl groups on the surface. − We have also shown that functionalization with pyridine, phosphines, and thiols of CNTs can be achieved in a number of ways, and this allows for coordination of metal ions, compounds, or nanoparticles. − Of these substituents, the pyridine functionality not only acts as an efficient ligand, ,, but also facilitates a decrease in the copper reduction potential, resulting in the preferential reduction of the surface-bound Cu­(II) to Cu­(I). − This coordinated Cu can then act as a catalyst for the deposition of further Cu­(II) ions from solution, allowing controlled seeded growth by electroless deposition. ,, In the case of CNTs, we have reported that pyridine-(py-)­functionalization may be achieved through the 1,3-dicyclohexylcarbodiimide (DCC) coupling of isonicotinic acid (with CNT–OH groups) or 4-hydroxypyridine (with CNT–CO 2 H groups) …”

Surface-initiated growth of copper using isonicotinic acid-functionalized aluminum oxide surfaces

“…The high stability of the isonicotinate's pyridine Lewis base interaction with Cu 2+ ensures the coordination. 22 Based on analogy with other Cu 2+ complexes with pyridine-type ligands, 40,41 immobilization with isonicotinic acid ligands will reduce the reduction potential resulting in the preferential reduction of the surfacebound Cu 2+ to Cu 0 . This already-deposited copper can then act as a catalyst for the deposition of further Cu 2+ ions from the solution, allowing the deposition to proceed in an autocatalytic manner.…”