摘要
联吡啶以分子水平掺入SiO2凝胶玻璃中,显示出独特的光谱性质。其发射光谱除了正常的S1→S0跃迁产生的中心位于400nm的发射峰外,还出现了中心位于454nm的激基缔合物发射峰。经200℃处理后,联吡啶分子受Si—O网络刚性约束,激基缔合发射峰消失,出现了基于S2→S0辐射跃迁产生的325nm高能级发射峰。至550℃处理后,因联吡啶分子基本进入Si—O三维网络的间隙,发射光谱中只剩下振动结构明显的高能级荧光峰。上述结果为表征有机/无机复合材料微结构演变提供了荧光探针工具。
Doping 2,2'-bipyridine molecules in silica gel glass leads to special spectroscopic properties compared to those dissolved in liquid solutions. For the sample without heat treatment, two broad bands centered at 400 nm and 454 nm respectively, induced by the radiative transition from the first excited level S_1 to the ground level S_0 and attributed to the emission from an excited dimeric 2,2'-~bipyridine species respectively, were observed. After heat-treated at 200 ℃, the excimer emission at 454 nm disappeared, and the sample exhibited another emission band centered at 325 nm due to the radiative transition from the second excited level S_2 to the ground level. S_2→S_0 transition resulted from restricting 2,2'-bipyridine molecules in silica networks. Only the structure emission of S_2→S_0 transition was observed when heat-treated at 550 ℃, which indicates that most of 2,2'-bipyridine molecules were entrapped in the cages of Si—O network. The above results can be used to characterize the microstructural evolution of hybrid organic-inorganic optical materials.
出处
《光谱学与光谱分析》
SCIE
EI
CAS
CSCD
北大核心
2005年第2期181-183,共3页
Spectroscopy and Spectral Analysis
基金
国家自然科学基金(90101007)
教育部跨世纪优秀人才培养计划资助
