Ultrafast electron - transfer reactions in radiation chemistry and radiation biology

这个更新提案描述了一个持续的研究计划，研究分子系统中具有生物和环境意义的超快电子转移反应。在过去的几年里，申请人建立了一个创新的项目，研究各种分子体系的超快电子转移反应，并发现它们在环境和生物过程中的重要性，从大气臭氧消耗到抗癌药物的作用机制，以治疗癌症。本课题旨在实时观察环境污染物有机卤素分子在电离/紫外辐射下在生物和环境系统中的超快电子转移反应，并评价其生物效应。申请人已经建立了一个高灵敏度飞秒（超快）时间分辨激光光谱，它非常强大，可以实时，直接观察水环境中有机卤素分子的超快电子转移反应。这是通过在分子水平上实时观察化学反应而提供的非凡机会。本研究将利用新型的超快激光光谱技术，结合DNA损伤和细胞死亡等生物分析方法。该项目对了解有机卤素污染物的分子反应机理及其对地球环境和人类健康的影响具有重要意义。此外，本工作开发的反应机制可能会导致发现保护人类暴露于有机卤素和辐射的分子剂，并开发一种高效经济的处理环境有害有机卤素材料的技术。

This renewal proposal describes a continuous research program to study ultrafast electron-transfer reactions in molecular systems of biological and environmental significance. Over the past several years, the applicant has built an innovative program to study ultrafast electron-transfer reactions of various molecular systems and to discover their importance for environmental and biological processes, ranging from atmospheric ozone depletion to the mechanisms of action of anticancer drugs for cancer treatment. The objectives of this proposal are to obtain real-time observations of ultrafast electron transfer reactions of organohalogen molecules, recognized as environmental pollutants, in biological and environmental systems under ionizing/UV radiation and to evaluate their biological effects. The applicant has built a high-sensitivity femtosecond (ultrafast) time-resolved laser spectroscopy, which is very powerful for real-time, direct observation of ultrafast electron-transfer reactions of organohalogen molecules in an aqueous environment. This is the remarkable opportunity afforded through the real-time observation of chemical reactions at the molecular level. The proposed research will utilize the novel ultrafast laser spectroscopic technique combined with biological analysis methods such as DNA damage and cell death assays. This project will have significance for understanding the molecular reaction mechanisms of organohalogen pollutants and their effects on Earth's environment and human health. Moreover, the reaction mechanism developed in this work may lead to the discovery of molecular agents for protection of humans exposed to organohalogens and radiation and the development of an efficient and economical technology for disposal of environmentally hazardous organohalogen materials.