密度泛函方法研究噻唑橙类菁染料的光谱性质

摘要

4-( Diethylamino ) butyl substituted trimethylthiazole orange ( DEAB-TO3 ) is essentially nonfluorescent in aqueous solution, which can be used to detect nucleic acids in cells.The spectroscopic properties of 4-(two ethyl amino) butyl substituted methyl thiazole orange(DEAB-TO1) and DEAB-TO3 were studied by density functional theory method.The geometry optimization of the ground state and the excited state reveal highly distorted configuration of the excited state.Spectral analysis and orbital analysis show that the first excited state is a dark state with twisted intermolecular charge transfer.The ground state and the excited state potential energy curves show that DEAB-TO1 and DEAB-TO3 have very low energy gap and rotational energy barrier.These results explain their low background fluorescence.%4-(二乙基氨基)丁基取代的三甲川噻唑橙(DEAB-TO3)具有极低的本底荧光可用于核酸检测.本文运用密度泛函理论研究了4-(二乙基氨基)丁基取代的一甲川噻唑橙(DEAB-TO1)和DEAB-TO3光谱性质.基态和激发态几何优化显示激发态构型高度扭曲;光谱计算和轨道分析得出第一激发态是暗态,出现了扭曲的分子内电荷转移;势能曲线计算可知,DEAB-TO1和DEAB-TO3有着极低的能隙和旋转能垒.以上结果解释了本底荧光极弱的实验现象.