Kinetics and mechanism of oxidation of excited state Tris‐(2,2′‐bipyridyl)‐ruthenium (II) complex by peroxomonosulfate, peroxodisulfate, and peroxodiphosphate

Abstract

Excitation of Ru(bipy);'ion by visible radiation of wavelength A = 436 nm in aqueous medium in presence of inorganic peroxides, peroxomonosulfate (PMS), peroxodisulfate (PDS), and peroxodiphosphate (PDP) was found to generate Ru(bipy),3'. The kinetics of this photochemical oxidation of Ru(bipy);' by each peroxide was followed spectrophotometrically and found to obey a total second-order, first-order each in [Ru(bipy):+] and [peroxide]. In the absence of light, thermal reaction of PMS and PDS with Ru(bipy);+ occurred but only when a t 1.0 M [H'] and M [peroxide]. The reaction of PMS with the complex is found to be cyclic, ie., Ru(bipy);+ formed oxidizes PMS itself and such a reaction was not observed in the case of PDS and PDP. The effects of pH, [peroxide], and [Ru(bipy);'] on the visible light induced oxidation of Ru(bipy);' by these peroxides are investigated. The results are discussed with suitable reaction mechanisms.

Kinetic Investigation of Oxidation of Aromatic Anils by Potassium Peroxymonosulfate in Aqueous Acidic Medium

“…+ [8], amino acids [9], sulfide ion [10], tris(2,2-bipyridyl)Ru(II) [11], Ti(III), Fe(II), and α-oxygen-substituted radicals [12], NO 2 − ion [13], parasubstituted anilines [14], aminobenzoic acids [15], "Co 2+ " ion in the presence of molybdate ion, [16], and that of [Co(II)W 12 O 40 ] 6− [17]. Schiff bases are nitrogen donor ligands (-CH=N-) that form complexes by donating an electron pair to a metal atom in the formation of coordination compounds.…”

“…In acid medium, the triple salt gives the active “HSO 5. − HSO 5, − ” a potentially important strong oxidant, which is first described in the oxidation reactions and some of the later studies including the oxidations of aldehydes , [(NH 3 ) 5 CoS 2 O 3 ] + , amino acids , sulfide ion , tris(2,2‐bipyridyl)Ru(II) , Ti(III), Fe(II), and α‐oxygen–substituted radicals , NO 2 − ion , parasubstituted anilines , aminobenzoic acids , “Co 2+ ” ion in the presence of molybdate ion, , and that of [Co(II)W 12 O 40 ] 6− . Schiff bases are nitrogen donor ligands (–CH=N–) that form complexes by donating an electron pair to a metal atom in the formation of coordination compounds.…”

Kinetics and mechanism of peroxysulfate/NaNO2 mediated nitration of phenols in aqueous bisulfate medium

“…Review articles published by House [1], Wilmarth and Haim [2] furnish excellent bibliography and summary of the results pertain to the kinetic studies and their plausible mechanisms prior to 1961. On the otherhand, Potassium peroxymonosulfate (potassium monopersulfate, Caroat, Oxone or PMS) is well known for the oxidation of boron-, nitrogen-, phosphorus-, and sulfur-containing compounds [10][11][12][13][14][15][16][17][18][19][20][21][22][23][24]. In highly acidic solutions the standard electrode potential for this compound is + 2.51 V with a half reaction generating the hydrogen sulfate (pH = 0), which makes it as effective oxidizing agent [23].…”

Kinetics and mechanism of the oxidation of glyoxylic acid by peroxodisulfate induced by irradiation with visible light of aqueous solutions containing tris (2,2′-bypyridine)ruthenium(II) ion

“…Peroxodisulfate is considered to be a strong oxidant both in aqueous and alkaline media. 1 Comparing peroxodisulfate and peroxomonosulfate, the reactions of the former are slower than the reactions of the latter, despite the fact that the potentials of the redox couples viz. E SO 2are 1.84V, 3 and 2.01V, 2 respectively.…”

“…These compounds are extensively used both in oxidation studies of organic/inorganic compounds as well as in reactions of synthetic 4 application. They are also efficient reagents in generating radicals by two successive one electron-transfer [5][6][7] steps. The reactions are activated by visible light and the photosplitting yields more powerful oxidising sulphate free radicals.…”