Photoreduction of thiazine dye with trimethylamine
Joint Authors
Uddin, Fahim
Zuhayr al-Hasanayn, Qadi
Yusufzai, Ayyub Khan
Source
The Arabian Journal for Science and Engineering. Section A, Science
Issue
Vol. 26, Issue 2ِAِ (31 Jul. 2001), pp.109-125, 17 p.
Publisher
King Fahd University of Petroleum and Minerals
Publication Date
2001-07-31
Country of Publication
Saudi Arabia
No. of Pages
17
Main Subjects
Abstract EN
Thionine, being a typical representative of thiazine dyes, was selected for investigations of photochemical reactions with organic reductants such as trimethylamine in 50% aqueous methanol.
The photochemical reduction was carried out in a specially designed apparatus provided with a double-walled temperature-controlled reaction cell.
Transmitted light was observed in terms of electrical signals through calibrated galvanometers.
Acidities of solutions were controlled by acetate buffers and determined by means of the spectrophotometric method in terms of Hammett acidity function {H0).
It was observed that quantum yield (0) is a function of acidity (H0) as well as concentration of reductant (AH2).
The quantum yield was found to be independent of the concentration of thionine dye.
The results have been interpreted in terms of a proposed mechanism.
The ratios of certain rate constants for the proposed mechanism have been evaluated.
It was concluded that the protonated triplet excited state of thionine (Th.H 2t) makes a major contribution to the determination of quantum yield (
The complex (Th.H2t.
AH2) is the rate controlling species and it may undergo either a electron transfer process or a free radical transfer process.
It was also found that the quantum yield is controlled by two equilibria: (i) triplet excited state of thionine with proton and protonated triplet state of thionine; and (ii) protonated triplet excited state of thionine with reductant and associated complex of thionine with reductant (Th.H 2t.
AH2).
American Psychological Association (APA)
Uddin, Fahim& Zuhayr al-Hasanayn, Qadi& Yusufzai, Ayyub Khan. 2001. Photoreduction of thiazine dye with trimethylamine. The Arabian Journal for Science and Engineering. Section A, Science،Vol. 26, no. 2ِAِ, pp.109-125.
https://search.emarefa.net/detail/BIM-389453
Modern Language Association (MLA)
Zuhayr al-Hasanayn, Qadi…[et al.]. Photoreduction of thiazine dye with trimethylamine. The Arabian Journal for Science and Engineering. Section A, Science Vol. 26, no. 2ِAِ (Jul. 2001), pp.109-125.
https://search.emarefa.net/detail/BIM-389453
American Medical Association (AMA)
Uddin, Fahim& Zuhayr al-Hasanayn, Qadi& Yusufzai, Ayyub Khan. Photoreduction of thiazine dye with trimethylamine. The Arabian Journal for Science and Engineering. Section A, Science. 2001. Vol. 26, no. 2ِAِ, pp.109-125.
https://search.emarefa.net/detail/BIM-389453
Data Type
Journal Articles
Language
English
Notes
Includes bibliographical references : p. 125
Record ID
BIM-389453