【作者】 龚伟；

【导师】 秦金贵；

【作者基本信息】 武汉大学 ， 有机化学， 2005， 硕士

【摘要】 随着信息时代的到来,高速光通讯、光信息处理和光电子学等实用领域取得了飞速发展,二阶非线性光学材料在这些领域中的应用前景得到越来越广泛的重视。有机非线性光学材料与无机材料相比具有非线性光学系数大、响应速度快、损伤阀值高、介电常数低、可加工性良好等优点。为了达到实用化的要求,尚有一个很关键的挑战性课题有待于进一步地得到解决:设计并合成出兼具大的分子一阶超极化率、良好的光学透明性和较高的热稳定性的二阶非线性光学发色团分子。 本论文由两部分研究工作组成。第一部分(第二章)首次设计并合成了一类8个新型具有大的分子一阶超极化率、良好透明性的吲哚类有机发色团分子。第二部分(第三章)首次设计并合成了两类共16个新型具有大的分子一阶超极化率、良好透明性的三苯胺类有机发色团分子。第四章则讨论了以上三类共24个发色团的光学性能和热稳定性能。各章的主要内容简述如下: 第一章在简要介绍非线性光学有关知识的基础上,分别从高β值发色团分子的设计合成、高β值和良好热稳定性发色团的设计合成以及高β值和良好透明性发色团的设计与合成三方面,综述了最近几年中有机二阶非线性光学发色团的研究进展,并在此基础上提出本论文的设计思想。 第二章首次设计合成了8个含有呋喃乙烯基吲哚体系或噻吩乙烯基吲哚体系的新型有机二阶非线性光学发色团分子,这8个新化合物经过核磁、红外、紫外、质谱和元素分析鉴定为目标化合物。 第三章首次报道了8个分别以呋喃和噻吩为共轭桥,三苯胺为给体部分的二维∧型有机二阶非线性光学发色团分子。同时首次设计合成了三苯胺为给体,呋喃和噻吩分别为共轭桥的一类共8个新型一维D—π—A型发色团分子作为参照物。这两类共16个新化合物经过核磁、红外、紫外、质谱和元素分析鉴定为目标化合物。 第四章简要介绍超瑞利散射测试方法的基本原理,然后讨论了前两章合成的三类共24个发色团的线性光学性能和热稳定性能。将吲哚呋喃发色团和另一类二乙氨基呋喃发色团的光学性质进行了比较。实验结果显示:吲哚呋喃发色团的最大吸收波长比二乙氨基呋喃类似物蓝移26～30nm。这可能是吲哚呋喃发色团分子由于给体基团吲哚环上氮原子的孤对电子离域化使分子内电荷转移效率有些降低而发生蓝移,证实了我们的设计思想。另外,在这三类发色团分子中以噻吩作为共轭桥的发色团透明性均要略好于呋喃为共轭桥的类似发色团。TGA结果显示这些发色团分子具有良好的热稳定性。这些发色团的非线性光学性能正在测试当中。更多还原

【Abstract】 Organic second-order nonlinear optical (NLO) materials have attracted much attention in the past two decades due to their huge potential applications in many different fields and many advantages over inorganic materials such as large nonlinearities, ultrafast response, high optical damage threshold, low dielectric, good processbility, integrability etc. One of the major challenges in this research is to design and synthesize second-order NLO chromophores possessing simultaneously large first-order molecular hyperpolarizability (β), good transparency and thermal stability; another is multifunctionalized polymeric NLO materials heralded as promising for application in high-tech.Chapter 1 gives a brief introduction on nonlinear optics, and recent progress of organic second-order nonlinear optical chromophores are reviewed from three aspects: the synthesis of new chromophores with large β value, the synthesis of new chromophores with large β value and good thermal stability, the synthesis of new chromophores with large β value and good transparency. Then the research strategy of the thesis is presented.In chapter 2, eight novel chromophores, in which N-hexylindole acts as an electron donor and furan or thiophene ring as a part of the conjugation bridge, are synthesized and characterized by ~1H-NMR, IR, UV-Vis spectra and elemental analysis.In charpter 3, eight new two-dimensional NLO chromophores containing triphenylamine with A type structure are designed and synthesized, and the corresponding one-dimensional NLO chromophores (common D—π— A type) are also synthesized for comparison. Their structure has been verified through the characterization of ~1H-NMR, IR, UV-Vis spectra and elemental analysis.Chapter 4 briefly describes the principle of Hyper-Rayleigh Scattering (HRS) method, which is used to determine the μβ values of NLO chromophores. Then the linear optical and thermal properties of the chromophores, which are synthesized and characterized in Chapter 2 and Chapter 3, are discussed. UV-VIS absorption phenomena of the four indole-based furan chromophores show 26~30nm blue-shifted absorption when compared with 5-[2-(4-diethylaminephenyl)vinyl]furan analogues. And this fact confirms our initial designing thought that indole-based chromophores can exhibit better transparency when compared with similar dialkylaniline-based chromophores. TGA results show that indole-based chromophores and triphenylamine-based chromophores are thermally stable up to 337℃ and 340℃, respectively. The measurement of these chromophores’ nonlinear optical properties is now in progress.更多还原