Palarographic studies of Pd (II), Pt (II) and Co (III) complexes of Polyaza Ligands
Sharma Punita
Department of SMJN (PG) College, Haridwar
Ain Qurratul
Department of Chemistry, SMIT, Gaziabad
Abstract
The polarographic technique gives a convenient method for studying redox reactions. The complexes studied give well defined, diffusion controlled one electron transfer reduction waves. The waves are irreversible in behavior. In case of P+(II) complexes, a regular cathodic shift in half wave potential of changing over from the trans structural macro cycle to the is observed. The redox properties of polyaza macrocyclic ligands have been of continued interest. As a result of these studies several macro cyclic complexes have been used as oxidant, reductants and electro catalysts. Earlier work on the redox behavior of macrocyclic complexes had mainly dealt with unsaturated systems. Later studies have dealt with many types of saturated systems also. It is important to study the effect of ligand structure, chelate ring size, donar unsaturation, substituent pattern and relative position of five and six membered chelate rings. It has been shown that a decrease in the ligand field strength of the macrocyclic ligands conclude in an anodic shift in the oxidant and reduction potentials. A change in the nature of the ring substituents changes the redox potential. The changes in the redox potential in these complexes are influence the substituents on the metal nitrogen interaction. In this we discuss the polarographic behavior of the complexes of (L1) Me2 (ET4) (14) diene (C20H40N4), Me2 (ET4) (14) ane (C20H44N4), (L3) Me6 (ET4) (14) diene (C16H35N4) and, (L4) Me2 (14) ane (C16H36N4). The polarograms of the complexes in aqueous solution were marked on a Metrohm Polarecord 50 usig a dropping mercury electrode (d.m.e.) as the working device. To choose a correct supporting electrolyte, polarographic wave of a few complexes were recorded in different electrolytes. It was observed that the best waves were prepared in 0.1 M sodium perchlorate. The one electron transfer irreversible waves related to the reduction of Pt (II) to Pt (I) and Pd (II) to Pd (I). It is reasonable to assume that the Pt – N distance is the significant factor. It has been seen that a change in the symmetry of the ligand result in change in the ligand field strength.
Polarographic technique, unsaturated systems, Redox potential
Balasubramanian, S., 1987. Macrocyclic dicarbinolamine complexes of nickel (II) with planar N4 (N2) ligands: synthesis and spectral and electrochemical properties. Inorganic Chemistry, 26(4):553-559.
Barefield, E. K., Wagner, F., and Hodges, K.D., 1976. Synthesis of macrocyclic tetramines by metal ion assisted cyclization reactions. Inorganic Chemistry, 15(6):1370-1377.
Barigelletti, F., and Flamigni, L., 2000. Photoactive molecular wires based on metal complexes. Chemical Society Reviews, 29(1):1-12.
Gomez-Romero, P., Witten, E. H., Reiff, W. M., and Jameson, G. B., 1990. Unusually strong antiferromagnetic coupling in unsymmetrical diiron (III). mu.-oxo complexes. Inorganic chemistry, 29(26):5211-5217.
Jubran, N., Cohen, H., and Meyerstein, D., 1985. Ring Size Effect on the Chemical Properties of Monovalent Nickel Complexes with Tetraazamacrocyclic Ligands in Aqueous Solutions. Israel Journal of Chemistry, 25(2)
:118-121.
Kalyanasundaram, K., 1982. Photophysics, photochemistry and solar energy conversion with tris (bipyridyl) ruthenium (II) and its analogues. Coordination Chemistry reviews, 46:159-244.
Keene, F. R., 1998. Isolation and characterisation of stereoisomers in di-and tri-nuclear complexes. Chemical Society Reviews, 27(3):185-194.
McAuley, A., Olubuyide, O., Spencer, L., and West, P. R., 1984. Kinetics and mechanism of reduction of nickel (III) complexes by titanium (III) in aqueous media. Inorganic Chemistry, 23(17):2594-2599.
McAuley, A., Oswald, T., and Haines, R. I., 1983. Kinetics and mechanisms of the oxidation of ascorbic acid and benzene diols by nickel (III) tetraazamacrocycles in aqueous perchloric acid. Canadian Journal of Chemistry, 61(6):1120-1125.
Meites, L. and Israel, Y., 1961. The calculation of electrochemical kinetic parameters from polarographic current-potential curves. Journal of the American Chemical Society, 83(24):4903-4906.
Mostafa, M. M., and Aicha, Y. N., 2002. Dioxouranium (VI) complexes of some macrocyclic ligands derived from 2, 6-diformyl-and 2, 6-diacetylpyridines and some aliphatic and aromatic amines. Synthesis and reactivity in inorganic and metal-organic chemistry, 32(1):143-154.
Nag, K., and Chakravorty, A., 1980. Monovalent, trivalent and tetravalent nickel. Coordination Chemistry Reviews, 33(2):87-147.
Olson, D. C., and Vasilevskis, J., 1969. Cyclic amine complexes of nickel (I),-(II), and-(III). Electrochemistry, preparation, and properties. Inorganic Chemistry, 8(8):1611-1621.
Priya, S., Balakrishna, M. S., Mague, J. T., and Mobin, S. M., 2003. Insertion of Carbon Fragments into P (III) − N Bonds in Aminophosphines and Aminobis (phosphines): Synthesis, Reactivity, and Coordination Chemistry of Resulting Phosphine Oxide Derivatives. Crystal and Molecular Structures of (Ph2P (O) CH2) 2NR (R= Me, n Pr, n Bu), Ph2P (O) CH (OH) n Pr, and cis-[MoO2Cl2 {(Ph2P (O) CH2) 2NEt-κ O, κ O}]. Inorganic chemistry, 42(4):1272-1281.
Raghuraman, K., Krishnamurthy, S. S., and Nethaji, M., 2003. Late transition metal complexes derived from diphosphazane monosulfide ligands: X-ray crystal structures of [Ru 3 (μ-CO)(CO) 7 (μ 3-S){Ph 2 PN ((S)-* CHMePh) PPh 2-κ 2 P, P}] and [Rh (CO) Cl {Ph 2 PN ((S)-* CHMePh) P (S) Ph 2}-κ 2 P, S]: Part 16. Organometallic chemistry of diphosphazanes. Journal of organometallic chemistry, 669(1):79-86.
Sorrell, T. N., 1989. Synthetic models for binuclear copper proteins. Tetrahedron, 45(1): 3-68.
Wang, S., Luo, Q., Zhou, X., and Zeng, Z., 1993. Synthesis, characterization and luminescence properties of lanthanide (III) complexes with 2, 6-bis (benzimidazol-2′-yl) pyridine. Polyhedron, 12(15):1939-1945.
Whitburn, K. D., and Laurence, G. S., 1979. Radical oxidation of nickel (II) complexes of tetra-azamacrocyclic ligands and the reactions of the resulting nickel (III) complexes: a pulse-radiolysis and flash-photolysis study. Journal of the Chemical Society, Dalton Transactions, 1:139-148.
Winkler, J. R., and Gray, H. B., 1992. Electron transfer in ruthenium-modified proteins. Chemical reviews, 92(3): 369-379.
Punita, S., & Qurratul, A. (2018). Palarographic studies of Pd (II), Pt (II) and Co (III) complexes of Polyaza Ligands. Environment Conservation Journal, 19(3), 145-148.
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© ASEA
Received: 20.05.2018
Revised: 21.06.2018
Accepted: 10.08.2018
First Online: 22.12. 2018
Publisher Name: Action for Sustainable Efficacious Development and Awareness (ASEA)
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