Reactions of Thiyl Radicals. XI. Further Investigations of Thiol–Disulfide Photolyses in the Liquid Phase
Reactions of Thiyl Radicals. XI. Further Investigations of Thiol–Disulfide Photolyses in the Liquid Phase
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XI。硫醇-二硫化物在液相中的光解反应。
DOI：
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发表时间：
1973
期刊：
影响因子：
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通讯作者：
A. R. Knight
中科院分区：
文献类型：
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作者：
Donna D. Carlson;A. R. Knight
C2 H5 SH液体在2537 A下的光解已经显示出以相等的速率产生H2和C2 H5 SSC 2 H5，量子产率为0.25。 乙硫醇-甲基二硫醚液体混合物的光解通过涉及硫代自由基攻击二硫键S-S键而传播的连锁反应，导致以高量子效率形成CH 3SH、C2 H5 SSC 2 H5以及作为中间体的CH 3SH、C2 H5 SSC 2 H5。长时间暴露后消耗，CH 3SSC 2 H5。交换过程顺序的最终结果是甲基二硫化物基本上不可逆地转化为甲硫醇。在室温下，同样的总反应以热的方式发生，但速率明显低于光化学过程。在等摩尔的CH_3SSCH_3 + n-C_3 H_7SSC_3 H_7和C_2 H_5SSC_2 H_5 + n-C_3 H_7SSC_3 H_7混合物中，光化学引发的交换反应生成不对称二硫化物的量子产率分别为6.9和4.4，而CH_3-SSCH_3 + C_2 H_5SSC_2 H_5混合物的量子产率为355。 在这三个...
The photolysis of C2H5SH liquid at 2537 A has been shown to give H2 and C2H5SSC2H5 at equal rates with a quantum yield of 0.25. The photolysis of ethanethiol – methyl disulfide liquid mixtures leads, via a chain reaction involving propagation by attack of thiyl radicals on the disulfide S—S bond, to the formation with high quantum efficiency of CH3SH, C2H5SSC2H5 and, as an intermediate that is consumed after long exposures, CH3SSC2H5. The net result of the sequence of exchange processes is the essentially irreversible conversion of the methyl disulfide into methanethiol. The same overall reaction occurs thermally at room temperature, but the rate is appreciably less than that of the photochemical process. The quantum yields of formation of the unsymmetrical disulfides arising from the photochemically initiated exchange reaction in equimolar mixtures of CH3SSCH3 + n-C3H7SSC3H7 and C2H5SSC2H5 + n-C3H7SSC3H7 have been shown to be 6.9 and 4.4, compared to 355 for CH3-SSCH3 + C2H5SSC2H5 mixtures. In all three ...