OXIDATION OF THIOSULFATE BY [OS(PHENANTHROLINE)3]3+ AND RELATED COMPLEXES

被引：39

作者：

SARALA, R ^{[1
]}

RABIN, SB ^{[1
]}

STANBURY, DM ^{[1
]}

机构：

[1] AUBURN UNIV,DEPT CHEM,AUBURN,AL 36849

来源：

INORGANIC CHEMISTRY | 1991年 / 30卷 / 21期

关键词：

D O I：

10.1021/ic00021a007

中图分类号：

O61 [无机化学];

学科分类号：

070301 ; 081704 ;

摘要：

The kinetics of oxidation of thiosulfate by [Os(phen)3]3+ (phen = phenanthroline) in aqueous media at 25.0-degrees-C and 0.10 M ionic strength has been investigated by stopped-flow spectrophotometry. With excess thiosulfate, the reaction has the stoichiometry 2[Os(phen)3]3+ + 2S2O3(2-) --> 2[Os(phen)3]2+ + S4O6(2-), and the rate law is -d[Os(III)]/dt = 2k1[Os(III)][S2O3(2-)] + 2k2[Os-(III)][S2O3(2-)]2. Oxidations by [Os(4,7-Me2phen)3]3+, [Os(5,6-Me2phen)3]3+, and [Os(5-Cl-phen)3]3+, having reduction potentials that span a range of 0.65 to 0.94 V, show similar rate laws. Both the k1 and k2 rate constants increase as the reduction potential of the oxidant increases. An outer-sphere electron-transfer mechanism is inferred for both terms, with S2O3- and S4O6(3-) as the primary intermediates.

引用

页码：3999 / 4007

页数：9

共 58 条

[1]

ALI M, 1990, INDIAN J CHEM A, V29, P528

[2]

BRAUER G, 1963, HDB PREPARATIVE INOR, V1, P393

[3] TITANIUM(III) CHEMISTRY - ELECTRON-TRANSFER REACTIONS WITH GROUND-STATE POLY(PYRIDINE)OSMIUM(III) COMPLEXES, QUENCHING REACTIONS WITH EXCITED-STATE POLY(PYRIDINE)RUTHENIUM(II) COMPLEXES, AND FORMAL REDUCTION POTENTIALS [J].