Design of Photo- and Electro-functional Polymers and Their Characteristics

本研究旨在设计新型光功能和电功能聚合物，即光导聚合物，并对其特性进行分析。主要研究结果可归纳为以下三点：1。(1)聚合物薄膜中的准分子形成和激发态能量迁移：我们发现准分子形成位点在聚合物薄膜中起着能量陷阱的作用。在对各种聚合物进行研究后，我们发现聚（（9-咔唑基）甲基丙烯酸乙酯）没有准分子形成位点，成为激发能迁移的良好聚合物介质。(2)聚合物固体中芳香族分子的光电离：我们研究了聚合物基体中芳香族分子通过双光子激发的光电离和聚合物固体中给体-间隔体-受体分子通过单光子激发的光电离。我们发现，在前一种情况下，聚甲基丙烯酸甲酯具有较弱的电子接受能力，并捕获通过双光子激发发射的电子，而在后一种情况下，光电离效率取决于间隔链的长度。我们发现准分子形成位点作为载流子陷阱位点，通过减少准分子形成位点的数量，可以制备出具有高载流子迁移率的体系，约为10^<-5>cm^2V^<-1>s^<-1>.3。为了估计自由基离子的稳定能，我们发展了两种方法：“自由基离子转移法”和“电荷共振带测量法”。利用这些技术，我们评估了聚合物链中产生的自由基离子的稳定能。

This investigation aimed at the molecular design of new photo- and electro-functional polymers, i. e., photoconductive polymers and the analysis of their characteristics. The main results are summarized in the following three items.1. Elucidation of carrier generation mechanism(1)Excimer formation and excited energy migration in polymer films : we found that excimer-forming sites act as energy-traps in polymer films. After serveying various polymers, we found that poly((9-carbazolyl)ethyl methacrylate)has no excimer-forming site and that it becomes a good polymer medium for excitation energy migration. (2)Photoionization of aromatic molecules in polymer solids : we studied both the photoionization of aromatic molecules in polymer matrices through two-photon excitation and the photoionization of donor-spacer-acceptor molecules through one photon excitation in polymer solids. We found that in the former case poly(methyl methacrylate)has a weak electron accepting ability and traps the electrons ejected through two-photon excitation and in the latter case photoionization efficiency depends on the length of spacer chains.2. Elucidation of carrier transport mechanism We found that excimer forming sires act as carrier-trap sites, nd by reducing the number of excimer forming sites, , could prepare the system having a high carrier mobility of ca. 10^<-5>cm^2V^<-1>s^<-1>.3. Estimate of the stabilization energy of the radical ions Produced by photochemical electron transfer For the estimate of the stabilization energies of the radical ions, we developed two methods : "radical ion transfer method" and "measurement of charge resonance band". Using these techniques we evaluated the stabilization energies of radical ions produced in polymer chains.