Toward a Quantitative Model for Excited-State Proton Transfer: From "Super" Photoacids to the Green Fluorescent Protein

本研究涉及开发用于检测非均相凝聚相（包括聚合物和蛋白质）中快速质子转移的工具，并形成实用的物理和理论模型供其使用。因此，这项工作包括设计新的基板，合成方法，动力学分析和理论建模。质子转移包含了一系列重要的生理和化学过程。这些过程大多发生在异质介质中，迄今为止，已经使用相对简单的扩散模型来解释这种系统中的速率。托尔伯特教授的工作将包括新光酸的合成、质子转移动力学的研究、光催化研究、界面和超临界流体中质子转移的研究以及绿色荧光蛋白（GFP）的研究。提出的研究代表了我们对激发态酸度的理解的一种努力，以便研究激发态质子转移的工具与研究光激发电子转移的工具一样容易获得。使用“超级”光酸催化化学放大反应的可能性，如光聚合和解聚合将被研究。基质对绿色荧光蛋白荧光特性的影响是目前研究的热点。GFP中生物激发态质子转移的研究将解决其中的一些影响。了解这些效应可以极大地扩展绿色荧光蛋白作为一种生物工具的用途。通过这个奖项，有机和大分子化学项目支持乔治亚理工学院化学与生物化学学院的Laren Tolbert教授的研究。质子转移是许多化学和生物系统的基本过程。因此，更好地了解控制激发态酸度的因素和不同环境下质子转移的机制是非常理想的目标。化学工业正日益走向所谓的“绿色”化学，这涉及到非均相无溶剂或最小溶剂的“复杂流体”环境。因此，需要能够研究这些系统中质子转移的实验方法。托尔伯特教授的方法是通过合成独特的底物来阐明过渡态，然后使用这些底物来测试强酸和弱酸状态下质子转移的各种模型。托尔伯特教授非常成功地让各个层次的学生参与研究，这些学生在化学的各个领域都做出了重大贡献。托尔伯特教授在培养少数民族博士生方面的强大的国际合作和良好的记录将为美国化工企业的人力资源需求做出重大贡献。

This research involves the development of tools for examining fast proton transfer in heterogeneous condensed phases, including polymers and proteins, and the formation of practical physical and theoretical models for their use. Thus, this effort includes design of new substrates, synthetic methodology, kinetic analysis, and theoretical modeling. Proton transfer encompasses a vast array of physiologically and chemically important processes. Most of these processes occur in heterogeneous media and relatively simple diffusion models have been used to account for the rates in such systems up to this point. Professor Tolbert's work will include the synthesis of new photoacids, studies of proton transfer dynamics, photocatalysis studies, studies of proton transfer at interfaces and in supercritical fluids and studies of Green Fluorescent Protein (GFP). The studies proposed represent an effort to advance our understanding of excited state acidity so that the tools available for studying excited-state proton transfer are as accessible as those for studying photoexcited electron transfer. The possibility of using "super" photoacids to catalyze chemically amplified reactions such as photo polymerizations and depolymerizations will be investigated. Matrix effects on the fluorescence properties of GFP are currently of great interest. The proposed studies in biological excited-state proton transfer in GFP will address some of these effects. Understanding these effects could greatly expand the usefulness of GFP as a biological tool.With this award, the Organic and Macromolecular Chemistry Program supports the research of Professor Laren Tolbert of the School of Chemistry and Biochemistry at Georgia Institute of Technology. Proton transfer is a fundamental process in numerous chemical and biological systems. Achieving a better understanding of the factors controlling excited state acidity and the mechanisms of proton transfer in diverse environments are therefore highly desirable goals. The chemical industry is increasingly moving toward so-called "green" chemistry, which involves heterogeneous solventless or minimal solvent "complex fluid" environments. Thus experimental approaches that are amenable to studying proton transfer in these systems are required. Professor Tolbert's approach has been to elucidate the transition state by synthesizing unique substrates, then using these to test various models for proton transfer both in the strong acid and weak acid regime. Professor Tolbert has been unusually successful in involving students at all levels in research and these students have contributed significantly in all areas of chemistry. The strong international collaborations and proven track record of Professor Tolbert in developing minority Ph.D. students will make significant contributions to the human resources needs of the chemical enterprise in the United States.