Details
| Original language | English |
|---|---|
| Pages (from-to) | 1661-1668 |
| Number of pages | 8 |
| Journal | Journal of the Chemical Society, Perkin Transactions 2 |
| Issue number | 9 |
| Publication status | Published - 1983 |
| Externally published | Yes |
Abstract
Absolute rate constants have been measured for the reactions of the protonated forms of chlorpromazine and promethazine, CZH+ and PZH+, with the electrophilic radicals .OH, Br 2-., (SCN)2-., I2 -., N3., Tl2+, Tl(OH)+, (t-C4H9S t-C4H9)+., (CH3SSCH3)+., and lipoate+. in the pH range 2-8. Values for these one-electron oxidations vary from k = 3.1 × 108 mol-1 dm3 s-1 for [(t-C 4H9S t-C4H9)+. + PZH +] to 5.5 × 109 mol-1 dm3 s-1 for (Br2-. + CZH+). The yields of the oxidation products, PTZH2+., vary from 28% for (.OH + CZH+) to 97% for [(SCN)2.- + CZH +]. The PTZH2+. radical cations exhibit characteristic absorption spectra with two maxima around 270 and 510 nm, and extinction coefficients of Sε(CZH2+.) = 56 000 mol-1 dm 3 cm-1 at 270 nm and 12 000 mol-1 dm 3 cm-1 at 510 nm, and ε(PZH2+.) = 62 500 mol-1 dm3 cm-1 at 265 nm and 9 500 mol -1 dm3 cm-1 at 505 nm. A transient absorption around 350 nm observed in the reaction of the phenothiazines with hydroxyl radicals is most probably the .OH-adduct, PTZH(OH)+.. The mechanism of the .OH-radical-induced oxidation of phenothiazines suggested in an earlier publication has been confirmed and enlarged.
ASJC Scopus subject areas
- Chemistry(all)
- General Chemistry
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In: Journal of the Chemical Society, Perkin Transactions 2, No. 9, 1983, p. 1661-1668.
Research output: Contribution to journal › Article › Research › peer review
}
TY - JOUR
T1 - Free radical induced one-electron oxidation of the phenothiazines chlorpromazine and promethazine
AU - Bahnemann, Detlef
AU - Asmus, Klaus Dieter
AU - Willson, Robin L.
N1 - Copyright: Copyright 2015 Elsevier B.V., All rights reserved.
PY - 1983
Y1 - 1983
N2 - Absolute rate constants have been measured for the reactions of the protonated forms of chlorpromazine and promethazine, CZH+ and PZH+, with the electrophilic radicals .OH, Br 2-., (SCN)2-., I2 -., N3., Tl2+, Tl(OH)+, (t-C4H9S t-C4H9)+., (CH3SSCH3)+., and lipoate+. in the pH range 2-8. Values for these one-electron oxidations vary from k = 3.1 × 108 mol-1 dm3 s-1 for [(t-C 4H9S t-C4H9)+. + PZH +] to 5.5 × 109 mol-1 dm3 s-1 for (Br2-. + CZH+). The yields of the oxidation products, PTZH2+., vary from 28% for (.OH + CZH+) to 97% for [(SCN)2.- + CZH +]. The PTZH2+. radical cations exhibit characteristic absorption spectra with two maxima around 270 and 510 nm, and extinction coefficients of Sε(CZH2+.) = 56 000 mol-1 dm 3 cm-1 at 270 nm and 12 000 mol-1 dm 3 cm-1 at 510 nm, and ε(PZH2+.) = 62 500 mol-1 dm3 cm-1 at 265 nm and 9 500 mol -1 dm3 cm-1 at 505 nm. A transient absorption around 350 nm observed in the reaction of the phenothiazines with hydroxyl radicals is most probably the .OH-adduct, PTZH(OH)+.. The mechanism of the .OH-radical-induced oxidation of phenothiazines suggested in an earlier publication has been confirmed and enlarged.
AB - Absolute rate constants have been measured for the reactions of the protonated forms of chlorpromazine and promethazine, CZH+ and PZH+, with the electrophilic radicals .OH, Br 2-., (SCN)2-., I2 -., N3., Tl2+, Tl(OH)+, (t-C4H9S t-C4H9)+., (CH3SSCH3)+., and lipoate+. in the pH range 2-8. Values for these one-electron oxidations vary from k = 3.1 × 108 mol-1 dm3 s-1 for [(t-C 4H9S t-C4H9)+. + PZH +] to 5.5 × 109 mol-1 dm3 s-1 for (Br2-. + CZH+). The yields of the oxidation products, PTZH2+., vary from 28% for (.OH + CZH+) to 97% for [(SCN)2.- + CZH +]. The PTZH2+. radical cations exhibit characteristic absorption spectra with two maxima around 270 and 510 nm, and extinction coefficients of Sε(CZH2+.) = 56 000 mol-1 dm 3 cm-1 at 270 nm and 12 000 mol-1 dm 3 cm-1 at 510 nm, and ε(PZH2+.) = 62 500 mol-1 dm3 cm-1 at 265 nm and 9 500 mol -1 dm3 cm-1 at 505 nm. A transient absorption around 350 nm observed in the reaction of the phenothiazines with hydroxyl radicals is most probably the .OH-adduct, PTZH(OH)+.. The mechanism of the .OH-radical-induced oxidation of phenothiazines suggested in an earlier publication has been confirmed and enlarged.
UR - http://www.scopus.com/inward/record.url?scp=37049091998&partnerID=8YFLogxK
U2 - 10.1039/P29830001661
DO - 10.1039/P29830001661
M3 - Article
AN - SCOPUS:37049091998
SP - 1661
EP - 1668
JO - Journal of the Chemical Society, Perkin Transactions 2
JF - Journal of the Chemical Society, Perkin Transactions 2
SN - 1472-779X
IS - 9
ER -