Molecular Triplet State Properties and Processes

在这个由化学部实验物理化学项目支持的项目中，Weisman将研究气相和溶液相分子的三重态光谱态的动力学和光物理学。气相研究将把三重态碰撞动力学的研究扩展到嘧啶、吡啶、同三嗪和萘，以了解三重态寿命对多余能量的依赖。时间分辨光学吸收光谱将用于收集数据。这些数据将使用主方程模拟进行分析，以提供更容易与理论计算进行比较的结果。溶液相富勒烯三态分子的能量学和动力学将通过瞬态吸收、光声和发射光谱测量来研究。待研究的分子包括C60、C70和更高级别的富勒烯。这些结果将为了解这些化合物的激发态行为以及规划和优化富勒烯的潜在应用形成光物理性质的数据库。研究多原子分子的三重态是很重要的，因为这种分子通常比分子的其他激发态持续的时间长得多，同时显示出化学反应、电子转移和能量转移的增加趋势。分子所处的激发态的特性也可以决定或改变特定化学反应的过程或效率。这个项目的研究是基础兴趣，但它们也可以影响实际应用，例如使用富勒烯衍生化合物的光学数据存储系统。

In this project supported by the Experimental Physical Chemistry Program of the Chemistry Division, Weisman will investigate the dynamics and photophysics of triplet spectroscopic states of both gas-phase and solution-phase molecules. The gas-phase studies will extend investigations of triplet collision dynamics to pyrimidine, pyridine, sym-triazine, and naphthalene in order to understand the dependence of triplet-state lifetime on excess energy. Time-resolved optical absorption spectroscopy will be used to gather data. These data will be analyzed using Master Equation simulations to provide results that can be more easily compared with theoretical calculations. The energetics and dynamics of solution-phase fullerene triplet-state molecules will be examined using transient absorption, photoacoustic, and emission spectroscopic measurements. Molecules to be studied include C60, C70, and higher fullerenes. The results will form a data base of photophysical properties for understanding excited-state behavior in these compounds and for planning and optimizing potential fullerene applications.Triplet states of polyatomic molecules are important to investigate because such molecules typically persist much longer than the molecule's other excited states while displaying increased tendencies for chemical reaction, electron transfer, and energy transfer. The identity of the excited state that a molecule can find itself in can also determine or alter the course or efficiency of a particular chemical reaction of interest. The studies in this project are of fundamental interest, but they can also impact practical applications, such as optical data storage systems using fullerene-derived compounds.