School of Chemistry and Centre for Synthesis and Chemical Biology, Trinity College, Dublin 2, Ireland.
J Am Chem Soc. 2011 Mar 30;133(12):4212-5. doi: 10.1021/ja1106089. Epub 2011 Mar 8.
The role of N1-substitution in controlling the deactivation processes in photoexcited cytosine derivatives has been explored using picosecond time-resolved IR spectroscopy. The simplest N1-substituted derivative, 1-methylcytosine, exhibits relaxation dynamics similar to the cytosine nucleobase and distinct from the biologically relevant nucleotide and nucleoside analogues, which have longer-lived excited-state intermediates. It is suggested that this is the case because the sugar group either facilitates access to the long-lived (1)n(O)π* state or retards its crossover to the ground state.
利用皮秒时间分辨红外光谱技术研究了 N1 取代在控制光激发胞嘧啶衍生物去活过程中的作用。最简单的 N1 取代衍生物 1-甲基胞嘧啶的弛豫动力学与胞嘧啶核苷酸碱基相似，与生物学上相关的核苷酸和核苷类似物不同，后者具有更长寿命的激发态中间体。这表明，这是因为糖基要么促进了长寿命（1）n(O)π*态的进入，要么阻碍了它向基态的交叉。
