PULSE-RADIOLYSIS STUDIES OF OXIDATION OF PHENOLS BY SO-4(-) AND BR-2(-) IN AQUEOUS-SOLUTIONS

被引：78

作者：

BANSAL, KM

FESSENDEN, RW

机构：

[1] CARNEGIE MELLON UNIV, RADIAT RES LABS, PITTSBURGH, PA 15213 USA

[2] CARNEGIE MELLON UNIV, MELLON INST SCI, DEPT SCI, PITTSBURGH, PA 15213 USA

来源：

RADIATION RESEARCH | 1976年 / 67卷 / 01期

关键词：

D O I：

10.2307/3574490

中图分类号：

Q [生物科学];

学科分类号：

07 ; 0710 ; 09 ;

摘要：

The reactions of .**GRAPHIC**. and .**GRAPHIC**. with phenol, o-, m- and p-cresol, and tyrosine were studied by pulse radiolysis methods using optical absorption and conductometric detectors. The reaction of .**GRAPHIC**. with the undissociated phenols was very rapid; in the case of tyrosine the rate constant was measured to be (3.0 .+-. 0.2) .times. 109 M-1 s-1. With tyrosine, formation of the phenoxyl radical was complementary to the disappearance of .**GRAPHIC**. with no intermediate having a lifetime > 0.1 .mu.s being possible. The reaction proceeds most probably by a direct oxidative electron transfer from the phenol. Reaction of Br2- with the phenoxide ions gave similar spectra. Calculated extinction coefficients based on reaction of .**GRAPHIC**. and .**GRAPHIC**. agreed to within the experimental error of .+-. 5%. Conductometric experiments (SO4- reaction) showed identical behavior for all phenols in near neutral solution with exactly the same yield of strong acid produced as when .**GRAPHIC**. abstracts from CH3OH. Thus, quantitative direct oxidation to a phenoxyl radical must occur in each case.

引用

页码：1 / 8

页数：8

共 19 条

[1]

Adams G., 1972, ADV RADIAT CHEM, V3, P125

[2]

ADAMS GE, 1972, ISRAEL J CHEM, V10, P1079

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