Novel Exciplexes

通过这一奖项，化学结构、动力学和机制B项目支持了罗切斯特大学约瑟夫·P·迪诺琴佐教授的研究。迪诺森佐教授和他的学生研究新的激基复合体(激发态复合体)，特别是阳离子(带正电的)激基复合体。这些研究活动提供了关于电子转移和新型激基复合物的基础知识。形成激基络合物的物质作为传感器、生物探针和有机发光二极管(OLED)具有潜在的应用前景。由于其在水中的溶解性，阳离子激基络合物在生物成像应用方面具有更大的潜力。这项研究为本科生、研究生和博士后在合成、电化学和时间分辨光谱学方面提供了丰富的教育经验。这项研究专门邀请关岛大学(美国领土上的一所少数民族院校)的本科生参加暑期研究机会。这一群体在科学、技术、工程和数学(STEM)领域的代表性较低。这个项目调查了两种最近在DInnocenzo实验室发现的新型电荷转移激基复合体中间体。一种类型的激基络合物是由阳离子激发态受体与中性供体反应形成的。研究目标包括通过辐射寿命的理论拟合来确定激基络合物的电子性质(例如电子耦合矩阵元素)，辐射寿命由时间相关的单光子计数(TCSPC)和荧光光谱确定。本项目通过测量阳离子激基络合物的一些光物理性质，检查各种介质(包括水)中的阳离子激基络合物，并合成分子内实例，来扩展阳离子激基络合物的一般性。一个相关的项目调查了在迪诺森佐教授的实验室中发现的例子，在这些例子中，观察到来自单一受体和供体的两个激基复合体发射。初步结果与两种激基复合物的溶剂重组能显著不同是一致的，表明它们在结构上存在重大差异。在这项研究中，学生学习如何合成、提纯和光谱表征化合物。学生还接受一系列非传统技术的培训，包括瞬变吸收光谱(TCSPC)、荧光测量、电化学和现代计算化学。通过研究培训的学生准备解决他们职业生涯中的各种多学科问题。这一奖项反映了NSF的法定使命，并通过使用基金会的智力优势和更广泛的影响审查标准进行评估，被认为值得支持。

With this award, the Chemical Structure, Dynamics, and Mechanism B program supports the research of Professor Joseph P. Dinnocenzo at the University of Rochester. Professor Dinnocenzo and his students investigate novel exciplexes (excited state complexes), especially cationic (positively charged) exciplexes. The research activities provide foundational knowledge about electron transfer and new types of exciplexes. Substances which form exciplexes have potential applications as sensors, as biological probes, and in organic light emitting diodes (OLED). Due to their solubility in water, cationic exciplexes have enhanced potential for development of biological imaging applications. The research provides a rich educational experience for undergraduate, graduate, and postdoctoral students, in synthesis, electrochemistry and time-resolved spectroscopy. This research specifically engages undergraduates from the University of Guam (a minority institution in the US Territory) for summer research opportunities. This group is underrepresented in science, technology, engineering and mathematics (STEM).This project investigates two types of novel, charge transfer exciplex intermediates that were recently discovered in the Dinnocenzo laboratory. One type of exciplex is formed by reaction of cationic, excited state acceptors with neutral donors. Research objectives include determining the electronic nature of the exciplexes (e.g. electronic coupling matrix elements) through theoretical fitting of radiative lifetimes, which are determined by Time Correlated Single Photon Counting (TCSPC) and fluorescence spectra. This project expands the generality of cationic exciplexes by measuring some of their photophysical properties, examining cationic exciplexes in a variety of media (including water), and synthesizing intramolecular examples. A related project investigates examples uncovered in the Professor Dinnocenzo's lab where two exciplex emissions are observed from a single acceptor and donor. Preliminary results are consistent with dramatically different solvent reorganization energies for the two types of exciplexes, indicating major differences in their structures. In this research, students learn how to synthesize, purify, and spectroscopically characterize compounds. Students also receive training in a range of less traditional techniques including transient absorption spectroscopy (TCSPC), fluorometry, electrochemistry, and modern computational chemistry. The students trained through the research are prepared to tackle a variety of multidisciplinary problems in their professional careers.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.