Rate Of Dehalogenation Research Articles

Photochemistry of aromatic compounds—VII: The influence of aliphatic amines on the photochemistry of 5-bromopyrimidines in mathanol

The UV irradiation of 2-methoxy-, 2-phenyl- and 2-dimethylamino-5-bromopyrimidine in methanol yields the corresponding dehalogenated, methylated and hydroxymethylated compounds. Added diethylamine or triethylamine strongly increases the rate of dehalogenation. It is suggested that amines influence the photochemistry of these compounds by transfering an electron to the excited state of the bromopyrimidines.

Kinetics of decomposition of copper benzoates

Halogenated compounds constitute one of the largest groups of environmental pollutants, partly as a result of their widespread use as biocides, solvents and other industrial chemicals. A critical step in degradation of organohalides is the cleavage of the carbonhalogen bond. Reductive dehalogenation is generally the initial step in metabolism under methanogenic conditions, which requires a source of reducing equivalents, with the halogenated compound serving as an electron acceptor. Dehalogenation is greatly influenced by alternate electron acceptors; e.g. sulfate frequently inhibits reductive dehalogenation. On the other hand, a number of halogenated aromatic compounds can be degraded under different electron-accepting conditions and their complete oxidation to CO2 can be coupled to processes such as denitrification, iron(III)-reduction, sulfate reduction and methanogenesis. Reductive dehalogenation was the initial step in degradation not only under methanogenic, but also under sulfate- and iron(III)-reducing conditions. Dehalogenation rates were in general slower under sulfidogenic and iron-reducing conditions, suggesting that dehalogenation was affected by the electron acceptor. The capacity for dehalogenation appears to be widely distributed in anoxic environments; however, the different substrate specificities and activities observed for the halogenated aromatic compounds suggest that distinct dehalogenating microbial populations are enriched under the different reducing conditions. Characterization of the microbial community structure using a combination of biomolecular techniques, such as cellular fatty acid profiling, and 16 S rRNA fingerprinting/sequence analysis, was used to discern the distinct populations enriched with each substrate and under each electron-accepting condition. These combined techniques will aid in identifying the organisms responsible for dehalogenation and degradation of halogenated aromatic compounds.

Steric Hindrance. II. The Rates of Dehalogenation of Methyl- and Dimethylstyrene Dibromides1

ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTSteric Hindrance. II. The Rates of Dehalogenation of Methyl- and Dimethylstyrene Dibromides1L. H. Schwartzman and B. B. CorsonCite this: J. Am. Chem. Soc. 1956, 78, 2, 322–325Publication Date (Print):January 1, 1956Publication History Published online1 May 2002Published inissue 1 January 1956https://doi.org/10.1021/ja01583a020RIGHTS & PERMISSIONSArticle Views93Altmetric-Citations12LEARN ABOUT THESE METRICSArticle Views are the COUNTER-compliant sum of full text article downloads since November 2008 (both PDF and HTML) across all institutions and individuals. These metrics are regularly updated to reflect usage leading up to the last few days.Citations are the number of other articles citing this article, calculated by Crossref and updated daily. Find more information about Crossref citation counts.The Altmetric Attention Score is a quantitative measure of the attention that a research article has received online. Clicking on the donut icon will load a page at altmetric.com with additional details about the score and the social media presence for the given article. Find more information on the Altmetric Attention Score and how the score is calculated. Share Add toView InAdd Full Text with ReferenceAdd Description ExportRISCitationCitation and abstractCitation and referencesMore Options Share onFacebookTwitterWechatLinked InReddit PDF (436 KB) Get e-Alerts Get e-Alerts