Chromium(VI)-thioester formation in N,N-dimethylformamide

Mazurek, W.; Nichols, Peter J.; West, Bruce O.

doi:10.1016/s0277-5387(00)83765-1

Cited by 14 publications

(26 citation statements)

References 23 publications

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“…However, as the concentration of chromate increased, the intensity of the coating peaks decreased and a new peak appeared at ;600 cm 2 1 . It has been shown that chromate interacts with glutathione (GSH) 25 and other thiols 26 to form a thiol ester in which the chromium binds to the sulfur atom:…”

Section: Resultsmentioning

confidence: 99%

Detection of Anions by Normal Raman Spectroscopy and Surface-Enhanced Raman Spectroscopy of Cationic-Coated Substrates

Mosier‐Boss

Lieberman

2003

Appl Spectrosc

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The use of normal Raman spectroscopy and surface-enhanced Raman spectroscopy (SERS) of cationic-coated silver and gold substrates to detect polyatomic anions in aqueous environments is examined. For normal Raman spectroscopy, using near-infrared excitation, linear concentration responses were observed. Detection limits varied from 84 ppm for perchlorate to 2600 ppm for phosphate. In general, detection limits in the ppb to ppm concentration range for the polyatomic anions were achieved using cationic-coated SERS substrates. Adsorption of the polyatomic anions on the cationic-coated SERS substrates was described by a Frumkin isotherm. The SERS technique could not be used to detect dichromate, as this anion reacted with the coatings to form thiol esters. A competitive complexation method was used to evaluate the interaction of chloride ion with the cationic coatings. Hydrogen bonding and pi-pi interactions play significant roles in the selectivity of the cationic coatings.

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Section: Resultsmentioning

confidence: 99%

Detection of Anions by Normal Raman Spectroscopy and Surface-Enhanced Raman Spectroscopy of Cationic-Coated Substrates

Mosier‐Boss

Lieberman

2003

Appl Spectrosc

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“…Aqueous complexes of hexavalent chromium have been the object of intensive studies, mainly due to their toxicity and their role in mutagenesis and carcinogenesis (Connett and Wetterhahn, 1985;Brauer and Wetterhahn, 1991;Mazurek et al, 1991). Monocromate complexes generally have a tetrahedral symmetry and bichromate complexes are formed by distorted tetrahedra linked at one apex by a bridging oxygen (Fig.…”

Section: Optimized Geometries and Vibrational Properties Of Cr(vi) Spmentioning

confidence: 99%

Ab-initio structure, energy and stable Cr isotopes equilibrium fractionation of some geochemically relevant H-O-Cr-Cl complexes

Ottonello

Zuccolini

2005

Geochimica et Cosmochimica Acta

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“…While researchers interested in the biological significance of Cr(VI) reduction have concentrated on cellular thiols and utilized aqueous conditions, the work of Mazurek et al. , has focused on the industrial significance of Cr(VI) reduction, using smaller, non-biological thiols in non-aqueous solvents. The reaction of Cr(VI) with alkane- and arenethiols in N,N -dimethylformamide (DMF), as in aqueous solution, resulted in the oxidation of thiols to the corresponding disulfides and the reduction of Cr(VI) to Cr(III) .…”

Section: Introductionmentioning

confidence: 99%

Chromium(VI) Forms Thiolate Complexes with γ-Glutamylcysteine, N-Acetylcysteine, Cysteine, and the Methyl Ester of N-Acetylcysteine

et al. 1996

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Reaction of potassium dichromate with gamma-glutamylcysteine, N-acetylcysteine, and cysteine in aqueous solution resulted in the formation of 1:1 complexes of Cr(VI) with the cysteinyl thiolate ligand. The brownish red Cr(VI)-amino acid/peptide complexes exhibited differential stability in aqueous solutions at 4 degrees C and ionic strength = 1.5 M, decreasing in stability in the order: gamma-glutamylcysteine > N-acetylcysteine > cysteine. (1)H, (13)C, and (17)O NMR studies showed that the amino acids act as monodentate ligands and bind to Cr(VI) through the cysteinyl thiolate group, forming RS-Cr(VI)O(3)(-) complexes. No evidence was obtained for involvement of any other possible ligating groups, e.g., amine or carboxylate, of the amino acid/peptide in binding to Cr(VI). EPR studies showed that chromium(V) species at g = 1.973-4 were formed upon reaction of potassium dichromate with gamma-glutamylcysteine and N-acetylcysteine. Reaction of potassium dichromate or sodium dichromate with N-acetylcysteine and the methyl ester of N-acetylcysteine in N,N-dimethylformamide (DMF) also led to the formation of RS-Cr(VI)O(3)(-) complexes as determined by UV/vis, IR, and (1)H NMR spectroscopy. Thus, an early step in the reaction of Cr(VI) with cysteine and cysteine derviatives in aqueous and DMF solutions involves the formation of RS-CrO(3)(-) complexes. The Cr(VI)-thiolate complexes are more stable in DMF than in aqueous solution, and their stability towards reduction in aqueous solution follows the order cysteine < N-acetylcysteine < gamma-glutamylcysteine < glutathione.

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Chromium(VI)-thioester formation in N,N-dimethylformamide

Cited by 14 publications

References 23 publications

Detection of Anions by Normal Raman Spectroscopy and Surface-Enhanced Raman Spectroscopy of Cationic-Coated Substrates

Detection of Anions by Normal Raman Spectroscopy and Surface-Enhanced Raman Spectroscopy of Cationic-Coated Substrates

Ab-initio structure, energy and stable Cr isotopes equilibrium fractionation of some geochemically relevant H-O-Cr-Cl complexes

Chromium(VI) Forms Thiolate Complexes with γ-Glutamylcysteine, N-Acetylcysteine, Cysteine, and the Methyl Ester of N-Acetylcysteine

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