Abstract
Syntheses of four iron(II)–azo amino acid complexes (1–4) with the general formula [FeIIL2(H2O)2]Cl2·nH2O, where L represents azo amino acid ligands, were carried out by direct mixing of N,N-diethylamino-4-nitrosoaniline, amino acids (alanine, histidine, tryptophan or phenylalanine) and Fe(II) ions in aqueous–methanol media. Azo ligands act as bidentate ligands and coordinate to Fe(II) ions through O-carboxylic and N-azo groups. Complexes 1–4 were characterized by IR, UV–visible spectra, thermogravimetric analyses (TGA) and conductance measurements. Kinetics of 1–4 oxidation by peroxydisulfate ions were studied spectrophotometrically in an aqueous media and in various aqueous–methanol binary mixtures at 25 °C. Kinetics of the oxidation followed pseudo-first-order reaction kinetics, \( k_{\text{obs}} = (k_{2} [{\text{S}}_{2} {\text{O}}_{8}^{2 - } ])[{\text{complex}}] \). Reactivity trends and their rate constants are discussed in terms of polarity, hydrophobicity of 1–4, and solvation effect of methanol. The effect of methanol ratios on the oxidation reaction is analyzed into initial (is) and transition state (ts) components. The decrease in the rate constant of the 1–4 oxidation, as the ratio of methanol increases, is predominantly caused by the effect of methanol on the initial state (ts) or by an increase in the Gibbs energy difference between is and ts.
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References
Fioriani, C., Fochi, G.: Azo-complexes of bis(cyclopentadienyl)-titanium and -vanadium; model systems for N-N multiple bond activation. J. Chem. Soc., Dalton Trans. 5, 1515–1521 (1983)
Oakes, J., Gratton, P.: Kinetic investigations of azo dye oxidation in aqueous media. J. Chem. Soc., Perkin Trans. II 9, 1857–1864 (1998)
Rau, H.: Spectroscopic properties of organic azo compounds. Angew. Chem. Int. Ed. 12, 224–235 (1973)
Zhou, Y.M., Leng, W.N., Xu, Q.H.: Synthesis of nonlinear optical polyimides containing benzothiazole moiety and their electro-optical and thermal properties. J. Polym. Sci. 42, 9253–9259 (2001)
Guangbin, W., Hou, L., Gan, F.: Optical storage properties of novel azo dye-in-polymer (PMMA) thin films. Phys. Status Solidi A 174, 269–275 (1999)
Shaker, A.M., Adam, M.S.: Synthesis and physico-chemical properties of some novel amino acid azo Fe(II) complexes. Synth. React. Inorg. Met-Org. Nono-Met. Chem. 33, 1081–1104 (2003)
Wang, X., Wang, Y., Li, J., Zhang, Z.: The new synthesis of azo compounds by 4-hydroxy-2,2,6,6-tertramethyl-l-piperidinyloxyl as the phases transfer dehydrogenation catalyst. Synth. Commun. 29, 157–162 (1999)
Blandamer, M.J., Burgess, J.: Initial state and transition state solvation in inorganic reactions. Coord. Chem. Rev. 31, 93–121 (1980)
Sieklucka, B., Macartney, D.H.: Kinetics and mechanisms of the oxidation of the octacyanoniobate(III)ion by oxyanions in alkaline aqueous media. Transit. Met. Chem. 21, 200–205 (1996)
Chen, M.H., Lee, S., Liu, S., Yeh, A.: Kinetic Studies of the reactions of pentacyanoferrate(ii) complexes with peroxydisulfate. Inorg. Chem. 35, 2627–2629 (1996)
Ramesh, K., Shylaja, S., Rajanna, K.C., Reddy, P.G., Saiprakash, P.K.: Polyethylene glycol-mediated kinetic study of nitrodecarboxylation of α,β-unsaturated acids by Blau’s Fe(III) bipy complex. Int. J. Chem. Kinet. 46, 126–137 (2014)
Rodriguez, A., Lopez-Cornejo, P., Perez, P., Muriel, F., Sanchez, F., Burgess, J.: Salt effects upon the S2O8 2− + Ru(NH3)5pz2+ electron transfer reaction. Int. J. Chem. Kinet. 31, 485–490 (1999)
Geselowitz, D.A., Taube, H.: Stereoselectivity in electron-transfer reactions. J. Am. Chem. Soc. 102, 4525–4526 (1980)
Wei, S.K., Yen, A.: Kinetic study of the Ru(II) catalyzed oxidation of pentacyanoferrate(II) complexes by peroxydisulfate. J. Chin. Chem. Soc. 46, 905–910 (1999)
Benko, J., Vollarova, O., Burgess, J., Lopez, P.: Correlation of volumes and entropies of activation for oxidation of coordinated sulfur in bis-ethylenediaminecobalt(III) complexes by peroxodisulphate, hydrogen peroxide and periodate and for peroxodisulphate oxidation of diimine–cyanide–iron(II) complexes. Tranition Met. Chem. 25, 674–679 (2000)
Babshet, R.M., Gokavi, G.S.: Kinetics and mechanism of oxidation of aurate(I) by peroxydisulphate in aqueous hydrochloric acid. Int. J. Chem. Kinet. 34, 589–594 (2002)
Farah, S.F.A., Sulfab, Y., Adnan, R.: Kinetics and mechanism of oxidation of some nickel(II)–imine–oxime complexes by peroxodisulfate in aqueous acidic solutions. Transition Met. Chem. 39, 247–252 (2014)
Hildenbrand, K.: The \( {\text{SO}}_{4}^{-} \) induced oxidation of 2’-deoxyuridine-5’-phosphate, uridine-5-phosphate and thymidine-5-phosphate. An ESR study in aqueous solution. Z. Naturforsch. 45, 47–58 (1990)
Shaker, A.M., El-Cheikh, F.M., Adam, M.S.S.: Kinetics and mechanism of the reaction of novel low spin Fe(II)–azo amino acid complexes with hydrogen peroxide in aqueous solutions and in aqua–methanol binary mixtures. Kinet. Catal. 52, 62–71 (2011)
Shaker, A.M., Awad, A.M., Adam, M.S.S.: Salt effects on reactivity of some Fe(II)–azo complexes catalyzing disproportionation of hydrogen peroxide. Monatsh. Chem. 137, 421–431 (2006)
Lalitham, J., Vijaraghavan, V.R.: Kinetics of oxidation of nickel(II) aza macrocycles by peroxydisulphate in aqueous media. J. Chem. Sci. 112, 507–514 (2000)
Truong, G.L., De Laat, J.D., Legube, B.: Effects of chloride and sulfate on the rate of oxidation of ferrous ion by H2O2. Water Res. 38, 2384–2394 (2004)
Apelblat, A., Korin, E., Mazurola, E.: Solubilities and vapour pressures of saturated aqueous solutions of sodium peroxydisulfate and potassium peroxydisulfate. J. Chem. Thermodyn. 33, 61–69 (2001)
Burgess, J., Shraydeh, B.: Reactions of tris-diimine and diimine-cyanide complexes of iron(II) with peroxoanions in solution. Polyhedron 11, 2015–2019 (1992)
Nassr, L.A.E., Shaker, A.M.: Kinetic and mechanistic aspects of reactivity of the oxidation of some Fe(II)–tris Schiff base complexes by peroxydisulfate: spectrophotometric tracer and solvent effect on the reactivity. Int. J. Chem. Kinet. 46, 701–710 (2014)
Sharma, P.K., Dubey, S.N.: Synthesis and structural studies of iron(II) complexes with N-salicylideneand N-(2-hydroxy-1-naphthylidene)amino acids. Indian J. Chem. 33A, 1113–1115 (1994)
Blandamer, M.J., Burgess, J., Clark, B., Duce, P.P., Hakin, A.W., Gosal, N., Radulovic, S., Guardado, P., Sanchez, F., Hubbard, C.D., Abu-Gharib, E.A.: Solubilities of salts and kinetics of reaction between hydroxide ions and iron(II–di-imine complexes in water–methanol mixtures. Derivation of single-ion transfer chemical potentials and their application to analysis of solvent effects on kinetic parameters. J. Chem. Soc., Faraday Trans. 1(82), 1471–1514 (1986)
Mohamad, A.D., Adam, M.S.S.: Reactivity of base catalysed hydrolysis of 2-pyridinylmethylene-8-quinolinyl-Schiff base iron(II) iodide complexes: solvent effects. Chem. Pap. 67, 464–476 (2013)
Alshehri, S., Blandamer, M.J., Burgess, J., Guardado, P., Hubbard, C.D.: Solvation and reactivity of the low-spin trisdiimine iron(II) complex of the schiff base ligand derived from 2-benzoylpyridine and 3,4-dimethylaniline, [Fe(Me2bsb)3]2+. Polyhedron 12, 445–454 (1993)
Myhovich, M.I., Kelman, V.A.: Theoretical and experimental study of spectroscopic characterizatics of aromatic amino acids. Ukr. J. Phys. 59, 581–588 (2014)
Geary, W.J.: The use of conductivity measurements in organic solvents for the characterisation of coordination compounds. Coord. Chem. Rev. 7, 81–122 (1971)
Angelici, R.J.: Synthesis and Technique in Inorganic Chemistry, 2nd edn. Saunders Company, Philadelphia (1977)
Haines, R.I., Pieda, D., Goulding, W.: Structure of tetraphenylarsonium tricyano-2,2′,6′,2′′-terpyridylferrate(II), AsPh4[FeII(terpy)(CN)3]; and kinetics of oxidation of the complex anion by peroxodisulfate in water and in binary aqueous mixtures. Transit. Met. Chem. 23, 763–769 (1998)
Haines, R.I., Rowley, J.E.: Structure and kinetics of oxidation of amphiphilic nickel(II) pentaazamacrocycles by peroxodisulfate and by a nickel(III) pendant-arm macrocycle. J. Incl. Phenom. Macro. Chem. 47, 25–32 (2003)
Haines, R.I., Baldwin, R.: Initial state versus transition state solvation effects on the kinetics of oxidation of nickel(II) dioxocyclam by peroxodisulfate. Transition Met. Chem. 27, 284289 (2002)
Rotzinger, F.P., Weber, J., Daul, C.: Base hydrolysis of (acidato)(pentaamine) complexes with inert metal centers: electronic structure of the intermediates, requirements for their formation, and the unique reactivity of the complexes of cobalt(III). Helv. Chim. Acta 74, 1247–1263 (1991)
Burgess, J., Galema, S.A., Hubbard, C.D.: Volumes of activation for dissociation of the cations of [tris-2,2′-bipyridyl]iron(II), [tris-1,10- phenanthroline]iron(II) and of other diimine iron(II) complexes in aqueous solution. Polyhedron 10, 703–709 (1991)
Abu-Gharib, E.A., Gosal, N., Burgess, J.: Kinetics of base hydrolysis of low-spin iron(II)-diimine complexes in methanol–water mixtures. Croat. Chem. Acta 74, 545–558 (2001)
Abu-Gharib, E.A., Komy, Z., Eltaher, A., Desoky, A., Burgess, J.: Kinetic, solvation and reactivity studies of iron(II) complexes of monoxime and dioxime ligands. Transit. Met. Chem. 30, 357–366 (2005)
El Marackchi, M., Tissier, C., Juillard, J.: Gibbs functions for transfer of divalent metal cations from water to water + methanol mixtures using potentiometry, polarography and solubility measurements. J. Electroanal. Chem. 420, 267–278 (1997)
Blandamer, J., Burgess, M.J., Reed, N.V., Wellings, P.: Kinetics of peroxodisulphate oxidation of dicyanobis-(2,2′-bipyridyl)iron(II) and of the tetracyano-2,2′-bipyridylferrate(II) anion; initial state and transition state effects in reactions of tris-diimine and diimine-cyanide complexes of iron(II). J. Inorg. Nucl. Chem. 43, 3245–3251 (1981)
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The authors greatly thank Vice-Presidency of Graduate Studies and Academic Research in King Faisal University for its financial support and encouragement to produce this work as a scientific project (Project Number 160034).
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Adam, M.S.S., El-Ayaan, U. & Mohamad, A.D.M. Oxidation Efficiencies of High Spin Fe(II)–Azo Amino Acid Complexes by Potassium Peroxydisulfate: Initial State–Transition State Solvation Effects. J Solution Chem 45, 772–790 (2016). https://doi.org/10.1007/s10953-016-0469-7
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DOI: https://doi.org/10.1007/s10953-016-0469-7