Excited and Ground State Hydrogen Migration

本项目由化学学部化学结构、动力学和机理B项目资助，由Matthew Platz教授指导，由美国国家科学基金（NSF）资助夏威夷大学希洛分校（UHH）的本科生研究。该研究结合了合成有机化学、光化学、反应混合物的化学分析和化学计算。本研究验证了先进理论方法在描述一种新的光化学反应机理方面的预测。夏威夷大学希洛分校（UH Hilo）一直是美国最多元化的四年制大学之一。该项目为来自历史上代表性不足的人群的经济困难的本科生提供了现代研究经验。通过合作关系，希洛大学的本科生在俄亥俄州立大学度过了夏季，在时间分辨飞秒测量领域的专家克里斯托弗·哈达德教授的指导下发展计算化学技能。在夏威夷的Hilo，本科生合成了重氮嘧啶、重氮化合物和恶二唑啉，将这些化合物暴露在单色紫外-可见辐射下生成了碳中间体，并分析了由此产生的烯烃产物的比例与激发波长的关系。在达到激发光子的临界能量后，烯烃立体异构体的比例发生显著变化，证实了理论的预测。通过合作关系，希洛大学的本科生在俄亥俄州立大学度过了几个月的暑假，在该领域专家克里斯托弗·哈达德教授的指导下发展计算化学技能。学生们还参加了飞秒时间分辨红外实验，测量碳烯的寿命和反应性。该奖项反映了美国国家科学基金会的法定使命，并通过使用基金会的知识价值和更广泛的影响审查标准进行评估，被认为值得支持。

In this project, funded by the Chemical Structure, Dynamic and Mechanism B Program of the Chemistry Division and directed by Professor Matthew Platz, NSF funds are used to support undergraduate research at the University of Hawaii-Hilo (UHH). The research incorporates synthetic organic chemistry, photochemistry, chemical analysis of reaction mixtures and chemical computations. This research tests the predictions of advanced theoretical methods in the description of a new photochemical reaction mechanism. The University of Hawaii Hilo (UH Hilo) consistently ranks among the most diverse four-year campuses in the nation. This project provides a modern research experience to economically-challenged undergraduate students from historically underrepresented populations. Through a collaborative relationship, UH Hilo undergraduates spend summer months at the Ohio State University developing skills in computational chemistry under the tutelage of Professor Christopher Hadad, an expert in the field of time-resolved, femtosecond measurements.In Hilo, Hawaii, undergraduate students synthesize diazirines, diazo compounds and oxadiazolines, expose these compounds to monochromatic ultraviolet-visible radiation to generate carbene intermediates, and analyze the ratio of alkene products so produced as a function of excitation wavelength. The predictions of theory are confirmed if the ratio of alkene stereoisomers changes dramatically after a critical energy of exciting photons is realized. Through a collaborative relationship, UH Hilo undergraduates spend summer months at the Ohio State University developing skills in computational chemistry under the tutelage of Professor Christopher Hadad, an expert in the field. The students also participate in femtosecond time-resolved infrared experiments which measure the lifetimes and reactivities of carbenes.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.