Oxidation of Sodium Hypophosphite by Oxygen in Alcoholic Solutions of Ferrum (III)

Authors

  • G. S. Polimbetova D.V. Sokolsky Institute of Organic Catalysis and Electrochemistry, 142 Kunaev St., 480100 Almaty, Kazakhstan
  • M. M. Aleshkova D.V. Sokolsky Institute of Organic Catalysis and Electrochemistry, 142 Kunaev St., 480100 Almaty, Kazakhstan
  • G. O. Bugubaev D.V. Sokolsky Institute of Organic Catalysis and Electrochemistry, 142 Kunaev St., 480100 Almaty, Kazakhstan
  • Zh.U. Ibraimova D.V. Sokolsky Institute of Organic Catalysis and Electrochemistry, 142 Kunaev St., 480100 Almaty, Kazakhstan
  • A.K. Borangazieva D.V. Sokolsky Institute of Organic Catalysis and Electrochemistry, 142 Kunaev St., 480100 Almaty, Kazakhstan

DOI:

https://doi.org/10.18321/ectj410

Abstract

Hypophosphites are widely used as reducers in the metal protection coating, as reagents in the synthesis
of various organophosphorus compounds, in analytical chemistry, and in many other fields. NaH2PO2 difficultly reacts with many oxidizers without catalysts despite of the significant reduction potential. The
kinetics and the mechanism of hypophosphite oxidation in aqueous acid solution of the metal and nonmetal
salts are studied in detail. The reactivity of hypophosphite in the organic solvents was not almost studied. In
this work the basic possibility of synthesis dialkylphosphites from cheap, accessible and harmless NaH2PO2
and alcohols is shown. Sodium hypophosphite is oxidized by oxygen in alcoholic solutions of FeCl3 at 50-
80°С to dialkylphosphites. Kinetic and mechanism of the reaction are investigated by methods of volumetry,
redox-potentiometry, GC, IR-, UV-, EPR-, Mössbauer- and NMR 31Р-spectroscopy and X-ray powder diffraction
analysis, optimum conditions are found, kinetic and activation parameters of the reaction are calculated.
It is shown, that the process follows redox-mechanism and consists of two key stages: reduction of Fe
(III) by hypophosphite with formation of dialkylphosphite and reoxidation of Fe (II) by oxygen. The coordination mechanism of reduction reaction of Fe (III) by hypophosphite is proposed. According to this mechanism the dialkylphosphite forms through innersphere redox-decomposition of intermediate alcoxyhypophosphite complex of Fe (III). The coordination mechanism of the process is confirmed by low values of Е≠ and negative activation entropies ΔS≠. The availability in an inner sphere of Fe (III) bromide, low-molecular alcohols, water, characterized by high acidity, increases the reaction rate of oxidative alcoxylation
of hypophosphite and promotes the further transformation of dialkylphosphite to di- and trialkylphosphate.

References

1. Abdreimova R.R., Faizova F.Kh, Akbayeva D. N., Polimbetova G.S., Aibasova S.M., Borangazieva A.K., Aliev M.B., Eurasian Chem. Tech.Journal 4:11 (2002).

2. Hussain J., Mishra S.K. and P.D. Sharma S.K.,J. Chem. Soc. Dalton Trans. 1:89 (1991).

3. Wojciechowski K., Malecki A., Int. J. Chem. Kinet. 31:737 (1999).

4. Kimura M., Seki K., Horei H., Tsukanara K., Bull. Chem. Soc. Jpn. 69:613 (1996).

5. Mohnot K., Sharma P.K., Banerji K.K., J. Indian Chem. Soc. 74:12 (1997).

6. Dichevskaya V.I., Kovbik A.A., Dulova V.I., Zaharov I.N., Koord. Khim. 8:1219 (1982).

7. Bogomolov A. Yu., Rostovshikova T.N., Smirnov V.V., Zh. Fiz. Khim. 69:1197 (1995).

8. Bogomolov A. Yu., Smirnov V.V., Rostovshikova T.N., Gerasimov P.V., Kinet. Katal. 36:253 (1995).

9. Yudelevich V.I., Sokolov L.V., Ionin B.I., Uspekhi Khimii 49:92 (1980).

10. Nifant'ev E.E. Chemistry of Hydrophosphoryl Compounds. Science, M., 1983, p. 246.

11. Nifant'ev E.E., Vasyatina L.K. NMR 31P − Spectroscopy. MGPI, M. 1986, p. 148.

12. Troickaya A.D. Problem of Coordination Chemistry. Reactionary Ability of Coordination Compounds.
Science, M. 1976, p. 7.

13. Temkin O.N. Introduction in Metallocomplex Catalysis. Catalysis and Coordination Chemistry. MITCT, M. 1980, p. 185.

14. Okamoto J., Kusano T., Takamuku S., Phosp. Sulfur, Silicon and Relat. Elem. 55:195 (1991).

Downloads

Published

2005-01-20

How to Cite

Polimbetova, G. S., Aleshkova, M. M., Bugubaev, G. O., Ibraimova, Z., & Borangazieva, A. (2005). Oxidation of Sodium Hypophosphite by Oxygen in Alcoholic Solutions of Ferrum (III). Eurasian Chemico-Technological Journal, 7(1), 33–39. https://doi.org/10.18321/ectj410

Issue

Vol. 7 No. 1 (2005)

Section

Articles

License

You are free to: Share — copy and redistribute the material in any medium or format. Adapt — remix, transform, and build upon the material for any purpose, even commercially.

Eurasian Chemico-Technological Journal applies a Creative Commons Attribution 4.0 International License to articles and other works we publish.

Subject to the acceptance of the Article for publication in the Eurasian Chemico-Technological Journal, the Author(s) agrees to grant Eurasian Chemico-Technological Journal permission to publish the unpublished and original Article and all associated supplemental material under the Creative Commons Attribution 4.0 International license (CC BY 4.0).

Further distribution of this work must maintain attribution to the author(s) and the published article’s title, journal citation, and DOI.