香豆素 153 的超快时间分辨荧光的极性溶剂化动力学。

Polar solvation dynamics of coumarin 153 by ultrafast time-resolved fluorescence.

机构信息

Department of Chemistry, Pohang University of Science and Technology (POSTECH), Pohang 790-784, South Korea.

出版信息

J Chem Phys. 2009 Dec 28;131(24):244507. doi: 10.1063/1.3276680.

PMID:20059079

Abstract

Polar solvation dynamics of coumarin 153 in acetonitrile, methanol, and butanol are investigated by dynamic Stokes shift function, S(t). In small protic solvents, it is known that an initial ultrafast component below 50 fs constitutes more than half of the total solvation process. We use fluorescence up-conversion technique via two-photon absorption process, which can provide 40 fs time resolution for the whole emission wavelength range. Moreover, time-resolved fluorescence spectra are recorded directly without the spectral reconstruction. We observe a temporal oscillation in frequency of whole emission spectrum in the solvation curve. In the obtained S(t), initial solvation time scale is 120 fs, invariant to solvents used in this experiment, although its amplitude varies in different solvents.

摘要

香豆素 153 在乙腈、甲醇和正丁醇中的极性溶剂化动力学通过动态斯托克斯位移函数 S(t)进行研究。在小质子溶剂中，已知初始超快分量低于 50 fs 构成总溶剂化过程的一半以上。我们使用通过双光子吸收过程的荧光上转换技术，该技术可以为整个发射波长范围提供 40 fs 的时间分辨率。此外，直接记录时间分辨荧光光谱，而无需光谱重建。我们在溶剂化曲线上观察到整个发射光谱的频率出现时间振荡。在获得的 S(t)中，初始溶剂化时间尺度为 120 fs，与本实验中使用的溶剂无关，尽管其幅度在不同溶剂中有所变化。