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化学学报
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化学学报 ›› 2002, Vol. 60 ›› Issue (10): 1768-1772. 上一篇    下一篇

研究论文

超支化聚合物的光物理行为及其压力效应

钟波;李沙瑜;李竑;何黎明;白凤莲;贺庆国;杨国强   

  1. 中国科学院化学研究所分子科学中心.北京(100101)
  • 发布日期:2002-10-15

High Pressure Effects on the Photophysical Properties of a New Type of Hyperbranched Conjugated Copolymer

Zhong Bo;Li Shayu;Li Hong;He Liming;Bai Fenglian;He Qingguo;Yang Guoqiang   

  1. Center for Molecular Sciences, Institute of Chemistry, Chinese Academy of Sciences.Beijing(100101)
  • Published:2002-10-15

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466

被引次数

10

在溶液中观察到超支化聚合物2-甲氧基-5-（2’-乙基已氧基）-对-苯乙烯/3 ，5-二乙烯基苯共聚体（MEH-PPV-HS_1）具有很强的荧光发射，并且在紫外区有两 个明显的相邻吸收带。分别激发这两个吸收带得到相同的荧光发射。在压力作用下 ，这两个吸收带表现出不同的压力效应，并且在不同的压力下分别激发这两个吸收 带时，所得到的荧光发射效率随压力的变化趋势表现出明显的不同。结果表明，这 两个相邻的吸收带分别来自于超支化聚合物分子中具有不同长短的有效共轭结构。 不同的共轭结构受光激发后到达不同的激发态。然后经过不同的松弛途径到达相同 的发光激发态而发出荧光。

关键词: 支化高聚物, 荧光分光光度法, 激发态, 苯乙烯, 二乙烯基苯

Photophysical properties of a new hyperbranched conjugated copolymer, poly(2-methoxy-5-(2'-ethylhexoxy)-p-phenylene vinylene)-alt- (3,5-bisvinylicbenzene) (MEH-PPV-HS_1), have been investigated. MEH-PPV- HS_1 shows two adjacent absorption bands in UV region, and similar fluorescence emission spectra are obtained when it is excited selectively by these two bands. Effects of pressure on these two absorption bands are quite different and the emission intensity may change with pressure in a different way for excitation at different band. All these results indicate that these two absorption bands are attributed to different effective conjugated structures in MEH-PPV- HS_1 respectively and the selective excitation of MEH-PPV-HS_1 generates different excited states, which transit to the same luminescent excited state by different relaxation pathway.

Key words: BRANCHED POLYMER, FLUOROSPECTROPHOTOMETRY, EXCITED STATE, STYRENE, DIETHENYLBENZENE

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