Hostname: page-component-8448b6f56d-cfpbc Total loading time: 0 Render date: 2024-04-25T00:40:02.477Z Has data issue: false hasContentIssue false

Ionization of Buthidazole, VEL 3510, Tebuthiuron, Fluridone, Metribuzin, and Prometryn

Published online by Cambridge University Press:  12 June 2017

J. B. Weber*
Affiliation:
Weed Sci., North Carolina State Univ., Raleigh, NC 27650

Abstract

Aqueous solutions of buthidazole {3-[5-(1,1-dimethylethyl)-1,3,4-thiadazol-2-yl]-4-hydroxy-1-methyl-2-imidazolidinone}, VEL 3510 {1-β,β-dimethoxyethyl-1-methyl-3-[5-(1,1-dimethylethyl)-1,3,4-thiadazol-2-yl] urea}, tebuthiuron {N-[5-(1,1-dimethylethyl)-1,3,4-thiadazol-2-yl]-N,N′-dimethylurea}, fluridone 1-methyl-3-phenyl-5-[3-trifluoromethyl)phenyl]-4(1H)-pyridinone, metribuzin [4-amino-6-tert-butyl-3-(methylthio)-as-triazin-5(4H)-one], and prometryn [2,4-bis(isopropylamino)-6-(methylthio)-s-triazine] were spectrophotometrically titrated to obtain pKA values. Ionizing properties of the chemicals were compared with other related compounds reported in the literature. The pKA values for the six herbicides were 0.6 and 11.3, 0.9 and 9.0, 1.2, 1.7, 1.1, and 4.1, respectively.

Type
Research Article
Copyright
Copyright © Weed Science Society of America 

Access options

Get access to the full version of this content by using one of the access options below. (Log in options will check for institutional or personal access. Content may require purchase if you do not have access.)

References

Literature Cited

1. Bohn, H. L., McNeal, B. L., and O'Conner, G. A. 1979. Soil Chemistry. John Wiley & Sons, Inc., New York, NY. 329 pp.Google Scholar
2. Chang, S. S. and Stritzke, J. F. 1977. Sorption, movement, and dissipation of tebuthiuron in soils. Weed Sci. 25:184188.Google Scholar
3. Gysin, H. 1962. Triazin herbicides – Their chemistry, biological properties and mode of action. Chem. and Ind. (London), pages 13931400.Google Scholar
4. Ladlie, J., Meggitt, W. E., and Penner, D. 1976. Effect of soil pH on microbial degradation, adsorption and mobility of metribuzin. Weed Sci. 24:477481.Google Scholar
5. MacDiarmid, B. N. 1975. VEL-5026 – A new herbicide for nonselective weed control. Proc. N. Z. Weed and Pest Control Conf. 28:154159.Google Scholar
6. Sandstrom, J. 1968. Recent advances in the chemistry of 1,3,4-thiadiazoles. Pages 165209 in Katritzky, A. R. and Boulton, A. J., eds. Advances in Heterocyclic Chemistry, Vol. 9. Acad. Press, New York.Google Scholar
7. Schmidt, R. R. 1973. Calculations on the herbicidal activity of metribuzin in relation to various soil properties. Proc. Eur. Weed Res. Counc. Symp. Herbicides-Soil. Pages 2430.Google Scholar
8. Waldrep, T. W. and Taylor, H. M. 1976. 1-methyl-3-phenyl-5-[3-(trifluoromethyl)phenyl]-4(1H)-pyridinone, a new herbicide. J. Agric. Food Chem. 24:12501251.Google Scholar
9. Weber, J. B. 1967. Spectrophotometrically determined ionization constants of 13 alkylamino-s-triazines and the relationships of molecular structure and basicity. Spectrochim. Acta 23A:458461.Google Scholar
10. Weber, J. B. 1977. Spectrophotometric analyses of herbicides. Pages 109177 in Truelove, Bryan ed., Res. Methods in Weed Sci. (2nd Ed.). South. Weed Sci. Soc., Auburn Printing Co., Auburn, AL.Google Scholar
11. Weber, J. B. 1980. Adsorption of buthidazole, VEL 3510, tebuthiuron, and fluridone by organic matter, montmorillonite clay, exchange resins, and a sandy loam soil. Weed Sci. 28. In press.Google Scholar
12. Woislawski, S. 1953. The spectrophotometric determination of ionization constants of basic dyes. J. Amer. Chem. Soc. 75:52015203.Google Scholar