ELECTROGENERATED CHEMILUMINESCENCE .30. ELECTROCHEMICAL OXIDATION OF OXALATE ION IN PRESENCE OF LUMINESCERS IN ACETONITRILE SOLUTIONS
ELECTROGENERATED CHEMILUMINESCENCE .30. ELECTROCHEMICAL OXIDATION OF OXALATE ION IN PRESENCE OF LUMINESCERS IN ACETONITRILE SOLUTIONS
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DOI：
10.1021/ja00458a028
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发表时间：
1977-01-01
影响因子：
15
通讯作者：
BARD, AJ
中科院分区：
文献类型：
--
作者：
CHANG, MM;SAJI, T;BARD, AJ
通过循环伏安法、旋转环盘伏安法和控制电位库伦法研究了草酸盐在铂电极上在乙腈溶液中的电化学氧化，结果表明，在约0.3 V的SCE下，草酸盐发生了不可逆的双电子氧化，生成了CO2，这些技术没有检测到中间产物。草酸盐在几种荧光剂（如rubrene、9,10 -二苯基蒽以及钌（II）和锇（ll）的联吡啶螯合物）存在下的氧化不产生光，但荧光剂的发光特性在添加剂和草酸盐同时氧化时发生。通过对存在噻吩和萘的排放条件的研究，得出了草酸氧化的机理和草酸氧化为C2O4-·的激发过程，C2O4-·快速分解为CO2和CO2-·。CO2-·可以将一个电子转移到添加剂分子中产生一个自由基阴离子，然后与电生成的自由基阳离子发生电湮灭反应。在非水溶剂中，在荧光化合物存在的情况下，草酰氯或草酸酯与过氧化氢反应产生的强烈化学发光引起了人们的极大兴趣。在提出的这些过程的机制中，氧丙酸酯和H2O2之间的反应产生二氧乙二酮(1)
The electrochemical oxidation of oxalate at a platinum electrode in acetonitrile solutions as studied by cyclic and ro-tating-ring disk voltammetry and controlled potential coulometry shows an irreversible two-electron oxidation at ca. 0.3 V vs. SCE to CO2 with no intermediates detectable by these techniques. The oxidation of oxalate in the presence of several fluo-rescers (such as rubrene, 9, 10-diphenylanthracene, and the bipyridyl chelates of ruthenium (II) and osmium (ll)) does not pro-duce light, butemission characteristicof the fluorescer occurs during the simultaneous oxidation of the additive and oxalate. Studies of the conditions for emission in the presence of thianthrene and naphthalene lead to a mechanism for the oxidation of oxalateand the excitation process based on oxidation of oxalate to C2O4-·, which undergoes rapid decomposition to CO2 and CO2-·. The CO2-· can transfer an electron to the additive molecule to produce a radical anion, which can then undergo an eel annihilation reaction with the electrogenerated radical cation.There has been much interest in the intense chemilumi-nescence which results from the reaction of oxalyl chloride or oxalate esters and hydrogen peroxide in the presence of fluo-rescent compounds in nonaqueous solvents. 1" 3 In theproposed mechanism for these processes, the reaction between the ox-alate ester and H2O2 producesthe dioxetanedione (1) as an