| Protonation-dissociation reactions of imazamethabenz-methyl and imazamethabenz-Acid in relation to their soil sorption and abiotic degradation. | |
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MedLine Citation:
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PMID: 19904942 Owner: NLM Status: In-Process |
Abstract/OtherAbstract:
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This paper present ultraviolet-visible absorption spectra of imazamethabenz-methyl (IMBM) (mixture of the isomers methyl 6-[(RS)-4-isopropyl-4-methyl-5-oxo-2-imidazolin-2-yl]-m-toluate, m-imazamethabenz, and methyl 2-[(RS)-4-isopropyl-4-methyl-5-oxo-2-imidazolin-2-yl]-p-toluate, p-imazamethabenz) and the corresponding carboxylic acid, imazamethabenz-acid (IMBA). The spectral characteristics are determined as functions of the pH. The appreciable absorbance in the visible (or near-ultraviolet) region of the spectra indicates that the natural photolytic degradation is possible. From variations of the maximum absorbances of the bands, the pK values of 3.4 +/- 0.2 and 9.4 +/- 0.2 were obtained for protonation of the imidazol (=N-) nitrogen and dissociation of the NH imidazol nitrogen of IMBM, respectively. For IMBA, the dissociation pK of the carboxylic group is very close to that of the imidazol (=N-) nitrogen, both being close to 3.3. The dissociation pK of the NH imidazol nitrogen for IMBA is 9.6 +/- 0.2. The role of the acid-base reactions on the sorption on soils of these herbicides is discussed. |
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Authors:
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Sara Pintado; Mercedes Ruiz Montoya; José Miguel Rodríguez Mellado |
Publication Detail:
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Type: Journal Article; Research Support, Non-U.S. Gov't |
Journal Detail:
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Title: Journal of agricultural and food chemistry Volume: 57 ISSN: 1520-5118 ISO Abbreviation: J. Agric. Food Chem. Publication Date: 2009 Dec |
Date Detail:
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Created Date: 2009-12-02 Completed Date: - Revised Date: - |
Medline Journal Info:
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Nlm Unique ID: 0374755 Medline TA: J Agric Food Chem Country: United States |
Other Details:
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Languages: eng Pagination: 11292-6 Citation Subset: IM |
Affiliation:
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Departamento de Quimica Fisica y Termodinamica Aplicada, Facultad de Ciencias, Campus Universitario Rabanales, edificio Marie Curie, Universidad de Cordoba, E-14014 Cordoba, Spain. |
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From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine
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