摘要
测量了对苯醌(p-benzoquinone,PBQ)在CS2中的可见吸收光谱,论证了该实验中发现的507 nm带来源于PBQ的n-π*单-三态跃迁.基于液芯光纤内共振拉曼散射可以提高拉曼光谱强度109倍这一技术,在10-3~10-6 mol·L-1的浓度范围首次探测到514.5 nm激光激发该跃迁而产生的共振拉曼光谱(1 439cm-1).分析认为该谱线来源于PBQ的n-π*单-三态跃迁的羰基伸缩振动(v c-o).实验发现,随着PBQ溶液浓度的降低,该谱线的拉曼频移发生蓝移.文章的研究结果将有助于理解PBQ电子结构与其光物理特性的相互关系,便于获得更丰富的分子结构信息.
The visible absorption spectra of p-benzoquinone (PBQ) in CS2 were measured, and a weak absorption band around 507 nm attributed to n-π^* singlet-triplet transition was demonstrated. Using the resonance Raman effect excited in liquid-core optical fiber which can enhance Raman intensity by 6-9 orders of magnitude, the authors obtained the 514.5 nm excited resonance Raman (RR) spectra of PBQ at 1 439 cm^-1 in the concentration range from 10^-3 to 10^-6 mol·L^-1. The new characteristic RR band is attributed to the symmetric C-O stretch ( v c-o ) of n-π^* singlet-triplet transition of PBQ. The resonance Raman shift is blue-shifted with decreasing concentration. The results of this paper are helpful for understanding the relationship between the electric structure and the photophysical properties of PBQ, and for obtaining more abundant structural information of molecules.
出处
《光谱学与光谱分析》
SCIE
EI
CAS
CSCD
北大核心
2005年第11期1821-1823,共3页
Spectroscopy and Spectral Analysis
基金
国家自然科学基金(10274023)资助项目
关键词
液芯光纤
n-π^*单-三态跃迁
共振拉曼光谱
Liquid-core optical fiber
n-π^* singlet-triplet transition
Resonance Raman spectra