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Title: Formation of radical cations of methoxylated benzenes by reaction with OH radicals, Ti$sup 2+$, Ag$sup 2+$, and SO$sub 4$$.$$sup -$ in aqueous solution. An optical and conductometric pulse radiolysis and in situ radiolysis electron spin resonance study

Abstract

The reactions of anisole, 1,2-, 1.3-, and 1,4-dimethoxybenzene and 1,2,3- , 1,2,4-, and 1,3,5-trimethoxybenzene with Tl$sup 2+$, Ag$sup 2+$, SO$sub 4$$.$$sup -$, and OH, respectively, were investigated in aqueous solution using optical and conductometric pulse radiolysis and in situ radiolysis ESR for detection. Tl$sup 2+$ and Ag$sup 2+$ were produced by reaction of OH with Tl$sup +$ and Ag$sup +$, respectively. SO$sub 4$$.$$sup -$ was generated by reaction of e$sup -$/sub aq/ with persulfate. Tl$sup 2+$, Ag$sup 2+$, and SO$sub 4$$.$$sup -$ react with the methoxylated benzenes by electron transfer to yield radical cations and Tl$sup +$, Ag$sup +$, and SO$sub 4$$sup 2-$, respectively. In the absence of cyclohexadienyl radicals the radical cations decay by second-order kinetics with rate constants ranging from less than 4 x 10$sup 3$ to 1 x 10$sup 9$ M$sup -1$ sec$sup -1$ depending on the positions of the methoxy groups relative to each other. OH radicals react with the methoxylated benzenes by addition to the aromatic ring with diffusion-controlled rates. Depending on conditions, the hydroxycyclohexadienyl radicals thus formed subsequently undergo three different types of reaction: (a) bimolecular decay (k values ranging from 8 x 10$sup 8$ to 2 x 10$sup 9$ M$sup -1$ sec $supmore » 1$); (b) reaction with protons to yield radical cations (k values from 2 x 10$sup 8$ to 1.4 x 10$sup 9$ M$sup -1$ sec$sup -1$); and (c) reaction with radical cations (k values from 8.6 x 10$sup 8$ to 3.5 x 10$sup 9$ M$sup -1$ sec$sup -1$). The assignment of the optical absorption spectra of the radical cations and the determination of the respective extinction coefficients is based on a combination of optical and conductivity data. The radical cation yield obtained at pH 1 by reaction of protons with the OH adducts of the substrates amounts to greater than 90 percent in the case of anisole, 1,3- dimethoxybenzene, and 1,3,5-trimethoxybenzene. (auth)« less

Authors:
; ;
Publication Date:
Research Org.:
Max-Planck-Institut fuer Kohlenforschung, Muelheim, Ger.
OSTI Identifier:
4097062
NSA Number:
NSA-33-014320
Resource Type:
Journal Article
Journal Name:
J. Phys. Chem., v. 79, no. 25, pp. 2773-2779
Additional Journal Information:
Other Information: Orig. Receipt Date: 30-JUN-76
Country of Publication:
United States
Language:
English
Subject:
N40300* -Chemistry-Radiation Chemistry; 400600* -Chemistry-Radiation Chemistry; *ANISOLE- CHEMICAL REACTIONS; *ETHERS- CHEMICAL REACTIONS; *HYDROXYL RADICALS- CHEMICAL REACTIONS; ANIONS; AQUEOUS SOLUTIONS; CATIONS; ELECTRON BEAMS; ELECTRON SPIN RESONANCE; MEV RANGE 01-10; PULSED IRRADIATION; RADIOLYSIS; SILVER COMPOUNDS; SOLVATED ELECTRONS; SULFATES; THALLIUM COMPOUNDS

Citation Formats

O'Neill, P, Steenken, S, and Schulte-Frohlinde, D. Formation of radical cations of methoxylated benzenes by reaction with OH radicals, Ti$sup 2+$, Ag$sup 2+$, and SO$sub 4$.$sup -$ in aqueous solution. An optical and conductometric pulse radiolysis and in situ radiolysis electron spin resonance study. United States: N. p., 1975. Web.
O'Neill, P, Steenken, S, & Schulte-Frohlinde, D. Formation of radical cations of methoxylated benzenes by reaction with OH radicals, Ti$sup 2+$, Ag$sup 2+$, and SO$sub 4$.$sup -$ in aqueous solution. An optical and conductometric pulse radiolysis and in situ radiolysis electron spin resonance study. United States.
O'Neill, P, Steenken, S, and Schulte-Frohlinde, D. 1975. "Formation of radical cations of methoxylated benzenes by reaction with OH radicals, Ti$sup 2+$, Ag$sup 2+$, and SO$sub 4$.$sup -$ in aqueous solution. An optical and conductometric pulse radiolysis and in situ radiolysis electron spin resonance study". United States.
@article{osti_4097062,
title = {Formation of radical cations of methoxylated benzenes by reaction with OH radicals, Ti$sup 2+$, Ag$sup 2+$, and SO$sub 4$.$sup -$ in aqueous solution. An optical and conductometric pulse radiolysis and in situ radiolysis electron spin resonance study},
author = {O'Neill, P and Steenken, S and Schulte-Frohlinde, D},
abstractNote = {The reactions of anisole, 1,2-, 1.3-, and 1,4-dimethoxybenzene and 1,2,3- , 1,2,4-, and 1,3,5-trimethoxybenzene with Tl$sup 2+$, Ag$sup 2+$, SO$sub 4$.$sup -$, and OH, respectively, were investigated in aqueous solution using optical and conductometric pulse radiolysis and in situ radiolysis ESR for detection. Tl$sup 2+$ and Ag$sup 2+$ were produced by reaction of OH with Tl$sup +$ and Ag$sup +$, respectively. SO$sub 4$.$sup -$ was generated by reaction of e$sup -$/sub aq/ with persulfate. Tl$sup 2+$, Ag$sup 2+$, and SO$sub 4$.$sup -$ react with the methoxylated benzenes by electron transfer to yield radical cations and Tl$sup +$, Ag$sup +$, and SO$sub 4$$sup 2-$, respectively. In the absence of cyclohexadienyl radicals the radical cations decay by second-order kinetics with rate constants ranging from less than 4 x 10$sup 3$ to 1 x 10$sup 9$ M$sup -1$ sec$sup -1$ depending on the positions of the methoxy groups relative to each other. OH radicals react with the methoxylated benzenes by addition to the aromatic ring with diffusion-controlled rates. Depending on conditions, the hydroxycyclohexadienyl radicals thus formed subsequently undergo three different types of reaction: (a) bimolecular decay (k values ranging from 8 x 10$sup 8$ to 2 x 10$sup 9$ M$sup -1$ sec $sup 1$); (b) reaction with protons to yield radical cations (k values from 2 x 10$sup 8$ to 1.4 x 10$sup 9$ M$sup -1$ sec$sup -1$); and (c) reaction with radical cations (k values from 8.6 x 10$sup 8$ to 3.5 x 10$sup 9$ M$sup -1$ sec$sup -1$). The assignment of the optical absorption spectra of the radical cations and the determination of the respective extinction coefficients is based on a combination of optical and conductivity data. The radical cation yield obtained at pH 1 by reaction of protons with the OH adducts of the substrates amounts to greater than 90 percent in the case of anisole, 1,3- dimethoxybenzene, and 1,3,5-trimethoxybenzene. (auth)},
doi = {},
url = {https://www.osti.gov/biblio/4097062}, journal = {J. Phys. Chem., v. 79, no. 25, pp. 2773-2779},
number = ,
volume = ,
place = {United States},
year = {Mon Dec 01 00:00:00 EST 1975},
month = {Mon Dec 01 00:00:00 EST 1975}
}