Collaborative Research: FRG: Nonpolar Electro-Optic Materials

本项目的目标是解决一类非极性电光材料的合成、表征和理论，这类材料对成像平面电光器件的应用很重要。对综合的强调包括几个重要的系统。非环端端lambda形分子和作为晶体紫家族新发色团的发色团正在被制备，以阐明在这些分子中已经观察到的大β 2mm组分的起源。这些发色团是随后的聚合物合成所必需的。大杂环生色团是由6个或6个以上的杂环组成的全共轭大环。巨杂环的大小和对称性决定了它的非线性性质。将合成具有大杂环或纵向扭曲色团核的盘状液晶，其官能团排列以提供所需的对称性。将检查各种盘状核，包括上述的曲酮或大杂环。纵向扭曲的椎间盘系统将被强调作为一个起点。通过在适当的位置上以共价连接形成聚合物，将上面所述的发色团，特别是末端的非环λ形分子，合并为亚基的螺旋聚合物将被创造出来。文件夹是一类具有理想对称性的聚合物。螺旋聚合物的生产首先需要有λ形的成分，因此最初的重点将放在单体上，一旦它们到手，聚合物将被制备和评估。在可能的情况下，将利用有机金属方法探索新的和增强的合成方法。在理论和设计领域，将使用启发式化学和量子化学计算进行发色团设计。许多这些计算将使用AMPAC和GAMESS通用原子和分子电子结构系统完成，也使用可以进行半经验计算的程序，如ZINDO，它可以更好地优化光学性质。这些程序将用于模拟材料的电光响应。此外，为了解决更大的分子和分子取向问题，启发式化学论证将被改编和使用。分析的、粗糙的蒙特卡罗和量子化学技术将用于研究发色团如何根据其分子结构排列，并分析实现最佳排列的方法。非线性光学特性研究将旨在评估非线性光学响应并验证模型和机制。将开展分子水平、体积水平和设备相关的研究，并将用于指导进一步的合成和理论工作。超瑞利测量将用于研究分子响应的表征以及与理论的比较。二次谐波产生和线性电光测量将在薄膜上进行。对这些潜在的器件材料、方法和概念的研究将有助于光学数据和图像处理的新电光技术，也有助于提高电光学的总体水平。该项目将教育和研究相结合，为研究生和博士后研究人员在光电子或相关关键劳动力领域的职业生涯做好准备。总的来说，该项目将加强在有机化学、物理和光学等跨学科领域受过训练的科学家的发展。该项目由化学部和材料研究部共同资助。

The goal of this project is to address synthesis, characterizaton, and theory of a class of nonpolar electro-optic materials important to applications in image-plane electro-optic devices. The emphasis on synthesis includes several important systems. Noncyclic Terminated Lambda-shaped Molecules and Chromophores as new chromophores in the Crystal Violet family are being prepared so as to elucidate the origins of the large beta 2mm component already observed in these molecules. These chromophores are required for subsequent polymer synthesis. Macroheterocyclic Ring Chromophore are composed of large fully conjugated rings comprised of six or more individual heterocyclic rings. The size and symmetry of the macroheterocycle will dictate its nonlinear properties. Discotic Chromophores with Macroheterocycle or Longitudinally Twisted Chromophore Cores as discotic liquid crystals which having functional groups arrayed to provide the desired symmetry will be synthesized. A variety of discotic cores are will be examined including the truxones or the macroheterocycles described above. The longitudinally twisted discotic systems will be emphasized as a starting point. Helical Polymers will be created that incorporate as subunits the chromophores created as described above, especially the noncyclic terminated lambda-shaped molecules, by covalently linking them in the appropriate positions to create a polymer. The foldamers are one class of polymers that have the desired symmetry. The production of helical polymers requires first that the lambda-shaped components are available and so initial emphasis will be on the monomers and once they are in hand then the polymers will be prepared and evaluated. Where possible new and enhanced synthesis methods will be explored using using organometallic approaches. In the area of theory and design, chromophore design will be carried out using heuristic chemistry and quantum chemical calculations. Many of these calculations will be done using AMPAC and the GAMESS general atomic and molecular electronic structure system, and also using a program that can do semi-empirical calculations such as ZINDO which are better optimized for optical properties. These programs will be used to model the electro-optic response of the materials. Also, to address larger molecules and issues of molecular orientation heuristic chemical arguments will be adapted and used. Analytical, crude Monte Carlo and quantum chemical techniques will be used to study how chromophores align according to their molecular structure, and to analyze methods for achieving optimal alignment. Nonlinear optical characterization studies will be aimed at evaluating the nonlinear optical response and to verify models and mechanisms. Molecular level, bulk level and device-related studies will be carried out and will be used to guide further synthetic and theoretical work. Hyper-Rayleigh measurements will be employed to study molecular response for characterization as well as comparison to theory. Second harmonic generation and linear electro-optic measurements will be carried out on films.%%%Research into these potential device materials, methods and concepts will contribute to new electro-optic technologies for optical data and image processing, and also to the knowledge required to promote electro-optics in general. This project integrates education and research in preparing graduate students and post-doctoral researchers for careers in optoelectonics or related critical workforce areas. Overall, the project will enhance development of scientists trained in interdisciplinary efforts in organic chemistry, physics, and optics. This project is co-funded by the Chemistry Division and the Division of Materials Research.