RESEARCH ON THE FLUCTUATION MODES CONTROLLING THE ULTRAFAST CHARGE MIGRATION IN AROMATIC VINYL POLYMERS.

控制芳香族乙烯基聚合物中超快电荷迁移的涨落模式的研究。

• 批准号: 10640490
• 负责人: MIYASAKA Hiroshi
• 金额: $ 2.11万
• 依托单位: KYOTO INSTITUTE OF TECHNOLOGY
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for Scientific Research (C)
• 财政年份: 1998
• 资助国家: 日本
• 起止时间: 1998 至 1999
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-10640490/
• 关键词: ELECTRON TRANSFER; HOLE TRANSFER; PHOTOCONDUCTOR; PICPSECOND LASER SPECTROSCOPY; AROMATIC VINYL POLYMERS; ポリビニルカルバゾール; 光伝導

The transport of electrons initiated by photoexcitation is ubiquitous in nature as well as in artificial systems. Photocon-ductivity in aromatic vinyl polymers is one of the typical phenomena closely related to these fundamental processes. Since the band structures in the electronic states are not plausible because of rather small interaction among the pendant aromatic groups, hopping model has been proposed for this carrier transport processes. Still unclear are the factors regulating the charge shift reaction between two neighboring aromatic groups in a molecular level. To obtain deeper insights into this efficient electron transfer reaction, we have studied temperature dependence of the hole escape process in one of the typical photoconductive polymers, poly (N-vinylcarbazole) (PVCz), doped with electron acceptors by picosecond transient absorption spectroscopy and dichroism measurements and found that no temperature dependence was observed for the rate constant of the hole shift reaction in the initial stages after the photoexcitation in the temperature region between 77 and 295K.The present hole transfer rate constant and its temperature independence are not rationally accounted for by the standard theory of the ET reaction assuming very weak interaction between the reactants. By integrating the present results with the previous ones on the solution phase, it is indicated that large electronic interaction between the aromatics is an important factor regulating the rapid hole transfer also in the solid polymer films. In solid phase, the small fluctuation of the carbazolyl moiety in the hindered space of the polymer film (zero-point motion) may fluctuate the transfer integral and may lead to the rapid hole transfer reaction when the mutual orientation takes a favorable condition. This contribution of the fluctuation in the electronic interaction is strongly suggested to play an important role in the rapid hole migration in the aromatic vinyl polymer systems.

由光激发引发的电子输运在自然界和人工系统中普遍存在。芳香族乙烯基聚合物的光导性是与这些基本过程密切相关的典型现象之一。由于电子态的能带结构是不合理的，因为相当小的相互作用的侧芳基，跳跃模型已被提出的载流子输运过程。在分子水平上调控两个相邻芳香基团之间电荷转移反应的因素尚不清楚。为了更深入地了解这种有效的电子转移反应，我们研究了典型的光电导聚合物聚乙烯中空穴逃逸过程的温度依赖性（N-乙烯基咔唑）（PVCz），用皮秒瞬态吸收光谱和二向色性测量掺杂电子受体，并发现没有观察到温度依赖性的空穴位移反应的速率常数在初始阶段后，在77 ~ 295 K温度范围内的光激发。目前的空穴转移速率常数及其温度无关性不能用ET反应的标准理论合理地解释，假设反应物之间的相互作用非常弱。通过整合本结果与以前的溶液相，它表明，大的电子之间的相互作用的芳香族化合物是一个重要的因素，调节快速空穴传输也在固体聚合物膜。在固相中，咔唑基在聚合物膜的位阻空间中的微小波动（零点运动）可能会使传输积分发生波动，当相互取向处于有利条件时，可能导致快速的空穴传输反应。这种贡献的电子相互作用的波动强烈建议发挥重要作用的快速空穴迁移的芳香族乙烯基聚合物系统。

项目成果

宮坂博: "学会出版センター(印刷中)"芳香族高分子中の光誘起電子移動過程 季刊化学総説46,フェムト秒・ピコ秒領域の化学.

Hiroshi Miyasaka：“学会出版中心（印刷中）”芳香族聚合物中的光诱导电子转移过程，季刊化学评论46，飞秒和皮秒区域的化学。

H.Miyasaka: "Direct detection of the charge shift reaction in aromatic vinyl Polymers" Recent Res.Duel.in Physical Chem.2. 921-930 (1998)

H.Miyasaka：“直接检测芳香族乙烯基聚合物中的电荷转移反应”Recent Res.Duel.in Physical Chem.2。

Hiroshi Miyasaka: "Picosecond dichroism measurement of photoconductive poly(N-ninylcarbazole) solid films : temperature effect on the hole migration reaction"Chem. Phys. Lett.. 292. 339-344 (1998)

Hiroshi Miyasaka：“光电导聚（N-乙烯基咔唑）固体薄膜的皮秒二色性测量：温度对空穴迁移反应的影响”Chem。

Hiroshi Miyasaka: "Formation and deactivation of extremely long-lived charge- separated species in carbazolyl vinyl polymers absorbed on macroreticular resin"Liq. Crys. Mol. Crys.. 315. 193-198 (1998)

Hiroshi Miyasaka：“吸附在大网络树脂上的咔唑基乙烯基聚合物中极长寿命电荷分离物质的形成和失活”Liq。

Hiroshi Miyasaka: "Formation and deactivation of extremely long-lived charge-separated species in carbazolyl vinyl polymers absorbed on macroreticular resin."Liq. Crys. Mol. Crys.. 315. 193-198 (1998)

Hiroshi Miyasaka：“吸附在大网络树脂上的咔唑基乙烯基聚合物中极长寿命的电荷分离物质的形成和失活。”Liq。