三种氨基酸荧光光谱的量子化学研究

氨基酸荧光光谱的量子化学计算为氨基酸荧光分析方法的设计与选择提供了一定的理论依据。本文采用量子化学半经验方法AM1对三种氨基酸的荧光光谱进行了理论研究。对三种化合物的结构进行优化后 ,从其结构参数可知分子具有刚性平面结构 ,具有大的离域π键。并对优化后的构型作振动分析 ,均未出现虚频率 ,证明该结构是稳定构型。在此基础上 ,采用单激发态组态相互作用 (CIS)方法计算其荧光激发波长及强度 ,并给出了三种化合物荧光光谱的波长与CIS组态数之间的关系。所得计算结果与实验值基本吻合。

Quantum Chemistry Study on Fluorescence Spectra of Three Kinds of Amino Acids

Quantum chemistry calculation of fluorescence spectrum offers certain theoretical reference for designing and selecting fluorescent analysis methods of amino acids. A theoretical study on fluorescence spectra of three kinds of amino acids by semi-empirical AM1 is given in this paper. After geometries of the three compounds are optimized, it is known that the titled compounds have rigid planar construction and big unlocalized pi bond from structural parameters. For all optimal geometries, there is no imaginary frequency in vibrational analysis, which proves that the geometric configurations of the three compounds are stable. On this basis, the electronic spectra have been calculated by CIS method. All calculated results are basically consistent with experimental values.