水相中•HS的光谱表征及其与氧气的反应研究

利用激光光解-瞬态吸收技术探讨了水相?HS自由基的产生及其在水溶液中的化学行为. 实验中利用?OH与H2S反应以及266 nm激光直接光解HS?两种途径产生了?HS, 通过光谱解析, 得到了?HS的紫外-可见吸收光谱： 吸收范围为220~300 nm, 最大吸收在220 nm, 并且在250~270 nm有肩峰. 进一步的研究结果表明, 氧气饱和的水溶液中,?HS的化学行为非常活泼, 它首先与O2反应生成?SO2?, ?SO2?继续与O2发生电子转移反应生成SO2和?O2?, 后者在酸性条件下会很快地质子化生成?HO2.

Spectrum of ·HS and Its Reactions with Oxygen in Aqueous Solution

The 266 nm laser photolysis formation and chemical behavior of ?HS in aqueous solution have been studied by laser photolysis-transient absorption technique. The 266 nm laser photolysis of H2O2 leads to the formation of ?OH, which reacts with H2S to produce ?HS, while solutions of HS? can also be directly photolyzed with 266 nm laser pulses to produce ?HS radical. The transient UV-Vis absorption spectrum of ?HS has been attributed to 220~300 nm with a maximum absorption at 220 nm and a shoulder at 250~270 nm. The chemical behavior of ?HS is very active in oxygen saturated aqueous solution:?HS will first react with oxygen to form ?SO2?, which further reacts with another oxygen molecule with the production of SO2 and ?O2?. In acid solution, ?O2? immediately protonates to form ?HO2.