Reactions of Chromium vi

In the course of reactions of chromium(VI) with different substrates (inductors), depending on whether the inductor is 1- or 2-equivalent reagent, in the primary reaction formation of Cr(V) and Cr(IV), respectively, was assumed. However, no definite statement can be made as to whether the chromium species formed in the primary reaction or another chromium entity produced in a secondary step reacts with the acceptor. The possibility of simultaneous formation of both chromium species in the primary reaction can be excluded. 

Reaction of chromium (VI). with hydrc en peroxide in the presence of glutathione reactive intermediates and resulting DNA damage. Chem. Res. Tox. 3, 595-603. 

Already in 1982, it was suggested that the intermediate chromium(V) state is involved in the carcinogenic process.9 Reactive Cr(V) and Cr(IV) intermediates may be harmful in many ways acting as tyrosine phosphatase inhibitors, or by forming organic radicals upon reaction with cellular reductants, which in turn can react with O2 and lead to reactive oxygen species.10 Reaction of chromium(VI) with... 

References to the many extensive accounts of the preparation, properties and reactions of chromium(VI) compounds, and their industrial and analytical importance have been collected.2,1363... 

Aiyar J, Berkovits HJ, Floyd RA. et al. 1991. Reaction of chromium(VI) with glutathione or with hydrogen peroxide Identification of reactive intermediates and their role in chromium(VI)-induced DNA damage. Environ Health Perspect 92 53-62. 

Lay PA, Levina A. 1998. Activation of molecular oxygen during the reactions of chromium(VI/V/IV) with biological reductants Implications for chromium-induced genotoxicities. J Am Chem Soc 120 6704-6714. 

Stearns DM, Wetterhahn KE. 1997. Intermediates produced in the reaction of chromium(VI) with dehydroascorbate cause single-strand breaks in plasmid DNA. Chem Res Toxicol 10 271-278. 

Chromium(VI) oxide nitrate and vanadium(V) oxide nitrate were first prepared by Schmeisser and Lutzow by the reaction of chromium(VI) oxide and vanadium(V) oxide with nitrogen(V) oxide. The nitrogen(V) oxide was prepared in the solid state by dehydration of fuming nitric acid with phosphorus(V) oxide. The method described below simplifies the preparation of anhydrous nitrogen(V) oxide and shortens significantly the time required. The products obtained can be protected from hydrolysis by totally excluding water from the all-glass system. 

A hitherto unstudied bridging group is the chlorate ion. The complex [(H20)6Cr-(C103)] + has been produced by the reaction of chromium(vi) with HCIO2. 

Levina A, Ludwig C, Lay PA. 2003. Reactive intermediates formed during the reactions of chromium(VI) with glutathione which species are responsible for the DNA damage J Inorg Biochem 96(1) 177. 

Effects of cationic (cetylpyridinium chloride, CPC) and anionic (SDS) micelles on the rate of reaction of chromium(VI) oxidation of formaldehyde have been studied in the presence and absence of picolinic acid. Cationic micelles (CPC) inhibit whereas anionic micelles (SDS) catalyze the reaction rates that could be attributed to electrostatic interactions between reactants (cationic metal ions and catalyst H+) and ionic head groups of ionic micelles. Experimentally determined kinetic data on these metaUomicellar-mediated reactions have been explained by different kinetic models such as pseudophase ion-exchange (PIE) model, Monger s enzyme-kinetic-type model, and Piszkiewicz s cooperativity model (Chapter 3). The rate of oxidation of proline by vanadium(V) with water acting as nucleophile is catalyzed by aqueous micelles. Effects of anionic micelles (SDS) on the rate of A-bromobenzamide-catalyzed oxidation of ethanol, propanol, and n-butanol in acidic medium reveal the presence of premicellar catalysis that has been rationalized in light of the positive cooperativity model. ... 

Scrimin, P., Tecilla, P., Tonellato, U. MetaUomiceUes as catalysts of the hydrolysis of carboxylic and phosphoric acid esters. J. Org. Chem. 1991, 56(1), 161-166. Mondal, S.K., Das, M., Kar, D., Das, A.K. MiceUar effect on the reaction of chromium(VI) oxidation of formaldehyde in the presence and absence of picoUnic acid in aqueous acidic media a kinetic study. Indian J. Chem. Sect. A 2001, 40A(4), 352-360. 

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