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在DNA的辐射损伤中,胸腺嘧啶二聚作用被公认为与致癌作用有直接关联,因此胸腺嘧啶光解和辐解的稳定和不稳定产物的研究已有大量的报道。但由于在室温中胸腺嘧啶激发三重态的寿命短,克分子消光系数低,在亲质子溶剂中的量子产额明显比疏质子溶剂中的低,因而以往关于胸腺嘧啶的光解研究主要是用乙腈作溶剂。为了更清楚地了解胸腺嘧啶在水溶液中的光化学行为,我们利用毫微秒级激光动态吸收光谱装置,直接观察水溶液中胸腺嘧啶的瞬态产物及其演变过程,探讨它们的形成机理。
In DNA damage, thymine dimerization has been recognized as a direct link with carcinogenesis. Therefore, studies on stable and unstable products of thymidine photolysis and radiolysis have been reported. However, due to the short lifetime of thymine-excited triplet state at room temperature and the low extinction coefficient of molybdenum, the quantum yield in proton-containing solvents is obviously lower than that in aprotic solvents. Therefore, the previous photolysis study of thymine mainly uses Acetonitrile as a solvent. In order to understand the photochemical behavior of thymine in aqueous solution more clearly, we used nanosecond laser dynamic absorption spectroscopy to directly observe the transient products of thymine in aqueous solution and their evolution, and discuss their formation mechanism.