Quantum Electronics Laboratory, Faculty of Physics, Adam Mickiewicz University, Poznan, Poland.
J Phys Chem A. 2011 Dec 22;115(50):14300-5. doi: 10.1021/jp2055238. Epub 2011 Nov 23.
Photochemistry of 4-methyl-5-carboethoxy-1,2,3-thiadiazole (MCT) in solution was studied at room temperature using UV-vis and IR transient absorption spectroscopies (λ(ex) = 266 nm). Three deactivation pathways are discussed: thiirene formation, thioketene generation, and the internal conversion by repopulating MCT in the ground state. Ultrafast techniques show a very fast rise (<0.4 ps) of thiirene species in acetonitrile, possibly as a result of a rearrangement in the singlet excited state of MCT in concert with molecular nitrogen extrusion. The remarkable stability of thiirene in solution on a millisecond time scale is limited by the process of dimerization (thiirene-thiirene, thiirene-thioketene). NMR analysis permitted identification of stable photoproducts as 1,3-dithietane, 1,3-dithiole, and thiophene derivatives.
在室温下使用紫外可见和红外瞬态吸收光谱（λ（ex）= 266nm）研究了 4-甲基-5-羧酸乙酯-1,2,3-噻二唑（MCT）在溶液中的光化学。讨论了三种失活途径：硫烯形成、硫酮生成以及通过重新填充基态中的 MCT 进行内部转化。超快技术显示在乙腈中硫烯物种的快速上升（<0.4ps），可能是由于 MCT 在单重激发态中与分子氮的协同排出的重排。在毫秒时间尺度上，溶液中硫烯的显著稳定性受到二聚化过程（硫烯-硫烯、硫烯-硫酮）的限制。NMR 分析允许鉴定稳定的光产物为 1,3-二噻烷、1,3-二噻吩和噻吩衍生物。
