非共轭聚合物PPV衍生物中烷氧基团对发光性质的影响

Effect of Alkoxyl Radical in Conjugated-nonconjugated Multiblock Copolymers on Luminescent Characteristics

研究了 3种非共轭PPV聚合物以及 3种共轭PPV衍生物的吸收谱和发光光谱的特性。非共轭PPV聚合物上的侧链烷氧基团有着很强的供电子能力 ,对调节非共轭聚合物能带带隙有重要的影响 ,且离主链较近的碳原子对能带结构也有一定的影响。但当侧链上的碳原子数量很大 ,从 7个小时一直变化到 1 0小时 ,共轭PPV衍生物的吸收光谱和发光光谱变化较少 。

Since the discovery of poly(p-phenylenevinylene)electroluminescence in 1990,much effort has been devoted to the synthesis of various conjugated polymers and to adjustment of polymer energy gap by chemical and physical methods to realize the emission in whole range of visible light.Usually,among poly(p-phenylenevinylenen)and its derivatives,there are two kinds of methods to adjust their band gap.One is that the alkyl or alkoxyl sidechain are attached main chain to adjust the energy gap.Other is that the non-conjugated chain is inserted conjugated main chain,which can limit delocated-state electron in a short range and increase the energy gap.However,while the energy gap of conjugated polymer is adjusted by the alkoxyl chain or non-conjugated chain,we find that their attachment positions of main chain are related to the energy gaps. It this paper,we research the alkoxyl chain in the different position of main-chain how to change the luminescent properties.Here, the absorbance and luminescence characteristics of three conjugated-nonconjugated multiblock copolymers(CNCMBC)and three conjugated PPV derivative were investigated.For the alkoxyl radical in the side-chains of CNCMBC can strongly offer delocated electrons to conjugated main-chains,the band gap of CNCMBC can be significantly adjusted.Moreover,when alkoxyl chain locates in different position of various CNCMBC,the absorption and luminescent spectra shift.While the vicinity of carbon atoms in mainchain of CNCMBC can slightly affect the band structure.However,when the number rang of side-chain carbon atoms in conjugated PPV derivative changes from seven to twelve,the luminescence spectra are slightly changes and aren't significantly independent of band gap.Results show that the alkoxy chains in different position of PPV derivatives have different adjustment capability of energy gap.