Weak Electronic Couplings in Biradicals and Radical Pairs: Through-Bond, Through-Space, and Through-Solvent

电子自旋共振耦合的研究 在各种不同的环境中，双自由基物种将 进行。 时间分辨电子顺磁共振 将被用来研究取代基的影响，几何 约束，距离，溶剂和温度之间的 柔性有机双自由基 媒体将包括在 研究包括有机溶剂，超临界流体， 囊泡、胶束、液晶、聚合物和沸石。 耦合常数的大小将 提供关于通过溶剂的关键信息 与弱耦合系统中的键相互作用相比。 在 聚合物系统的情况下， 聚合物链中的双自由基位点将允许旋转 在终点和中心都要探测的障碍 聚合物的 此外，含有关键的 酮的浓度将被合成和研究 定义下一个发展中重要的参数 光降解高分子材料的产生。 %%% 有机动力学计划的这笔赠款支持 化学体系中双自由基相互作用的研究 北卡罗来纳州大学马尔科姆·福布斯教授 查佩尔山。 关键是要了解 分子系统的不同部分相互联系 其他电子，以便能够设计 这些分子能够在 一个分子装置的背景。 此外，合成 具有光降解塑料潜在用途的新材料 将以双基研究的结果为指导。 也 光化学反应性聚合物将被设计成增加 传统上非相互作用聚合物 材料.

An investigation of electron spin resonance couplings of biradical species in a variety of different environments will be conducted. Time-resolved electron paramagnetic resonance will be used to study the effects of substituents, geometrical constraints, distance, solvent, and temperature between the flexible organic biradicals. Media to be included in the investigation include organic solvents, super critical fluids, vesicles, micelles, liquid crystals, polymers, and zeolites. The magnitude of the size of the coupling constants will provide critical information with respect to through solvent versus through bond interactions in weakly coupled systems. In the case of the polymer systems, strategic placement of the biradical sites in the polymer chain will allow rotational barriers to be probed both at the end and at the center of the polymer. In addition, polymers containing critical concentrations of ketones will be synthesized and investigated to define the parameters important in development of the next generation of photodegradable macromolecular materials. %%% This grant from the Organic Dynamics Program supports the investigation of biradical interactions in chemical systems by Professor Malcolm Forbes at the University of North Carolina at Chapel Hill. It is critical to understand the method by which different parts of molecular systems communicate with each other electronically in order to be in a position to design molecules that are capable of performing specific functions in the context of a molecular device. In addition, the synthesis of new materials with potential use as photodegradable plastics will be guided by the results of the biradical studies. Also photochemically reactive polymers will be designed to increase the adhesion between traditionally non-interactive polymeric materials.