当前位置：
X-MOL 学术
›
Photochem. Photobiol.
›
论文详情
Our official English website, www.x-mol.net, welcomes your
feedback! (Note: you will need to create a separate account there.)
Mechanistic Study of the Peroxyoxalate System in Completely Aqueous Carbonate Buffer
Photochemistry and Photobiology ( IF 2.6 ) Pub Date : 2020-11-05 , DOI: 10.1111/php.13343 Felipe A Augusto 1 , Fernando H Bartoloni 1, 2 , Ana Paula E Pagano 1 , Wilhelm J Baader 1
Photochemistry and Photobiology ( IF 2.6 ) Pub Date : 2020-11-05 , DOI: 10.1111/php.13343 Felipe A Augusto 1 , Fernando H Bartoloni 1, 2 , Ana Paula E Pagano 1 , Wilhelm J Baader 1
Affiliation
|
The peroxyoxalate reaction is one of the most efficient chemiluminescence transformations, with emission quantum yields of up to 50%; additionally, it is widely utilized in analytical and bioanalytical assays. Although the real reason for its extremely high efficiency is still not yet understood, the mechanism of this transformation has been well elucidated in anhydrous medium. Contrarily, only few mechanistic studies have been performed in aqueous media, which would be of great importance for its application in biological systems. We report here our experimental results of the peroxyoxalate reaction in completely aqueous carbonate buffer, using fluorescein as chemiluminescence activator. The kinetics are very fast in the used basic conditions (pH > 9); despite this, reproducible kinetic results were obtained. The reaction proceeds by specific base catalysis, with rate-limiting attack of hydrogen peroxide anion to the oxalic ester, in competition with ester hydrolysis by hydroxide ion. Emission quantum yields increase with the hydrogen peroxide concentration up to an optimal concentration of 10 mmol L-1 . The infinite singlet quantum yield of (5.8 ± 0.2) × 10-7 is much lower than in anhydrous medium, however, it is similar to quantum yields measured before in partially aqueous media.
中文翻译：
全水碳酸盐缓冲液中过氧草酸盐体系的机理研究
过氧草酸盐反应是最有效的化学发光转化之一，发射量子产率高达 50%；此外，它还广泛用于分析和生物分析测定。虽然其极高效率的真正原因尚不清楚，但这种转变的机制已经在无水介质中得到了很好的阐明。相反，在水介质中进行的机械研究很少，这对其在生物系统中的应用非常重要。我们在这里报告了我们在完全水性碳酸盐缓冲液中过氧草酸盐反应的实验结果，使用荧光素作为化学发光激活剂。在所用的碱性条件下（pH > 9），动力学非常快；尽管如此，还是获得了可重复的动力学结果。该反应通过特定的碱催化进行，过氧化氢阴离子对草酸酯进行限速攻击，与氢氧根离子对酯的水解竞争。发射量子产率随着过氧化氢浓度增加至最佳浓度 10 mmol L-1 。(5.8 ± 0.2) × 10-7 的无限单线态量子产率远低于无水介质，但与之前在部分水性介质中测得的量子产率相似。
更新日期：2020-11-05
中文翻译：
全水碳酸盐缓冲液中过氧草酸盐体系的机理研究
过氧草酸盐反应是最有效的化学发光转化之一，发射量子产率高达 50%；此外，它还广泛用于分析和生物分析测定。虽然其极高效率的真正原因尚不清楚，但这种转变的机制已经在无水介质中得到了很好的阐明。相反，在水介质中进行的机械研究很少，这对其在生物系统中的应用非常重要。我们在这里报告了我们在完全水性碳酸盐缓冲液中过氧草酸盐反应的实验结果，使用荧光素作为化学发光激活剂。在所用的碱性条件下（pH > 9），动力学非常快；尽管如此，还是获得了可重复的动力学结果。该反应通过特定的碱催化进行，过氧化氢阴离子对草酸酯进行限速攻击，与氢氧根离子对酯的水解竞争。发射量子产率随着过氧化氢浓度增加至最佳浓度 10 mmol L-1 。(5.8 ± 0.2) × 10-7 的无限单线态量子产率远低于无水介质，但与之前在部分水性介质中测得的量子产率相似。
京公网安备 11010802027423号