Complex Ions of Chromium. VIII. Mechanism of Reaction of Organic Acid Anions with Chromium(III)<sup>1,2</sup>

Hamm, Randall E.; Johnson, Robert L.; Perkins, Ralph H.; Davis, Robert E.

doi:10.1021/ja01550a008

Cited by 73 publications

(21 citation statements)

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“…This observation clearly indicates the existence of chromium as Cr(III) in the form of complex species probably with oxalic acid as observed by other researchers [31,32] and not exist as free ion.…”

Section: Product Analysissupporting

confidence: 84%

Spectral Evidence for the One-Step Three-Electron Oxidation of Phenylsufinylacetic Acid and Oxalic Acid by Cr(VI)

Subramaniam¹,

Selvi²

2013

AJAC

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The co-oxidation of a mixture of phenylsulfinylacetic acid (PSAA) and oxalic acid (OxH 2 ) by Cr(VI) in 20% acetonitrile-80% water (v/v) medium follows third order kinetics, first order, each with respect to PSAA, OxH 2 and Cr(VI). The reaction involves nucleophilic attack of sulfur atom of PSAA on chromium of the oxidizing species, Cr(VI)-OxH 2 to form a ternary complex, Cr(VI)-OxH 2 -PSAA followed by a one-step three-electron reduction of Cr(VI) to Cr(III) and simultaneous oxidation of both the substrates. The reaction is catalysed by Mn 2+ ion while retarded by Al 3+ ion. Electron releasing substituents in the meta-and para-positions of the phenyl ring of PSAA enhance the rate of co-oxidation while electron withdrawing substituents retards the reaction. The Hammett plots at different temperatures exhibit excellent correlation with negative ρ values. The reaction series obey isokinetic relationship and the observed isokinetic temperature is lying below the experimental range of temperature.

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Section: Product Analysissupporting

confidence: 84%

Spectral Evidence for the One-Step Three-Electron Oxidation of Phenylsufinylacetic Acid and Oxalic Acid by Cr(VI)

Subramaniam¹,

Selvi²

2013

AJAC

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“…The stronger electrostatic interaction between oxalate and Cr(II1) may lead to more complicated limiting behavior near 0.01 M oxalate where oxalate makes up a significant portion of the total ionic strength of the test solutions. It is possible that salicylate would show the same type of behavior at higher concentrations (>0.01 M), especially considering that the final limiting rates for the two ligands are expected to be the same (6).…”

Section: Limiting Behavior For Reaction Of Cr(ll1)mentioning

confidence: 99%

“…These data were then modeled with eq. [6] and the ki values for the different pathways are presented in Table 2. The slope of the curve near pH 3.5 is not less than one as was observed for oxalate and salicylate.…”

Section: Rates Of Reaction Of Cr(ll1) With Humic Acidmentioning

confidence: 99%

A chemiluminescence study of the kinetics of reactions of Cr(III) with carboxylate ligands: oxalate, salicylate, and humic acid

Huizenga¹,

Patterson²

1990

Can. J. Chem.

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The reaction of Cr(1II) with chelate-forming carboxylate ligands can be monitored at the low ligand concentrations typical of natural waters by chemiluminescence analysis of unreacted Cr(II1). This technique is utilized here for the measurement of Cr(II1) reaction kinetics with oxalate, salicylate, and humic acid over a wider ligand concentration range than previously reported. Variation of the pH and ligand concentrations allowd the determination of rates of reaction by three pathways with different pH dependencies. The magnitude of rate constants of these pathways for Cr(II1) with inorganic (Cl-, SCN-) and carboxylate ligands gives insight into the reaction pathways for the environmentally important ligand humic acid. Introduction Knowledge of both the rate of conversion of aquated Cr(II1) to bound forms and the ultimate equilibrium speciation of Cr(III) are important in predicting its biogeochemical behavior in natural waters. In general, the reaction kinetics of Cr(II1) are dominated by the slow exchange of water molecules from the inner coordination sphere. The rates of reaction of Cr(II1) with inorganic ligands such as C1-and SCN-have been extensively studied either directly or indirectly by combination of aquation rate and equilibrium measurements and the results have been systematically compared (1). In contrast, the rates of reaction of Cr(III) with carboxylate ligands and humic materials have been little studied. The few studies available for carboxylate ligands have been conducted under acid conditions and at high ligand concentrations (2).The rates of reaction of Cr(II1) with carboxylate ligands at the low concentrations typical of dissolved organic matter in natural waters (about lop5 M) have not been reported. At such low concentrations, the rate of reaction should become dependent upon the ligand concentration. We have used chemiluminescence analysis to monitor rates of reaction of Cr(II1) with the carboxylate ligands oxalate, salicylate, and humic acid over a wide range of ligand concentrations ( l o p 2 to lop5 M). The technique involves the oxidation of luminol by hydrogen peroxide in the presence of unbound Cr(II1) to yield a product which luminesces (3). The intensity of luminescence is proportional to the u~e a c t e d Cr(II1) concentration. Because of its high sensitivity, chemiluminescence analysis is well suited to kinetic studies of Cr(II1) reacting with carboxylate and humic ligands at low concentrations.

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“…The 3+ with various amino acids have been reported [11][12][13][14][15][16][17][18][19][20][21][22][23][24]. Recently the reaction between Cr(H 2 O) 6 3+ with 1,3-propanediamine-N,N-diacetate-N,N'-di-3-propionate has been reported [25].…”

Section: Introductionmentioning

confidence: 99%

Kinetics and Mechanism of Reaction of cis-[Cr(C2O4)2(H2O)2]– with L-Dopa in Aqueous Medium: A Comparative Antiparkinsonian Studies

Rout¹,

Kar²,

Pattanaik³

et al. 2017

Asian J. Chem.

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The substitution reaction of cis-[Cr(C2O4)2(H2O)2]-with L-Dopa in aqueous medium has been studied over the range 35 ≤ t ≤ 50 °C, 3.5 (KNO3). The reaction takes place via an outer sphere association between cis-[Cr(C2O4)2(H2O)2]-and L-Dopa followed by chelation. Characterization of the product was done by physicochemical and infrared spectroscopic methods. The antiparkinsonian activity of L-Dopa was found to be less than that of the product chromium(III) complex.

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Complex Ions of Chromium. VIII. Mechanism of Reaction of Organic Acid Anions with Chromium(III)^1,2

Cited by 73 publications

References 0 publications

Spectral Evidence for the One-Step Three-Electron Oxidation of Phenylsufinylacetic Acid and Oxalic Acid by Cr(VI)

Spectral Evidence for the One-Step Three-Electron Oxidation of Phenylsufinylacetic Acid and Oxalic Acid by Cr(VI)

A chemiluminescence study of the kinetics of reactions of Cr(III) with carboxylate ligands: oxalate, salicylate, and humic acid

Kinetics and Mechanism of Reaction of cis-[Cr(C2O4)2(H2O)2]– with L-Dopa in Aqueous Medium: A Comparative Antiparkinsonian Studies

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Complex Ions of Chromium. VIII. Mechanism of Reaction of Organic Acid Anions with Chromium(III)1,2

Cited by 73 publications

References 0 publications

Spectral Evidence for the One-Step Three-Electron Oxidation of Phenylsufinylacetic Acid and Oxalic Acid by Cr(VI)

Spectral Evidence for the One-Step Three-Electron Oxidation of Phenylsufinylacetic Acid and Oxalic Acid by Cr(VI)

A chemiluminescence study of the kinetics of reactions of Cr(III) with carboxylate ligands: oxalate, salicylate, and humic acid

Kinetics and Mechanism of Reaction of cis-[Cr(C2O4)2(H2O)2]– with L-Dopa in Aqueous Medium: A Comparative Antiparkinsonian Studies

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Complex Ions of Chromium. VIII. Mechanism of Reaction of Organic Acid Anions with Chromium(III)^1,2