Reactivity and Spectroscopy of Small Metal and Semiconductor Clusters

这项研究是实验物理化学计划的一部分，将需要对金属和半导体小分子进行光谱研究，并研究金属团簇的反应性随大小和组成的函数。这些研究将有助于发展金属/半导体电子结构的统一理论，该理论可以解释物理和化学性质随尺寸的变化。团簇将通过激光蒸发脉冲超音速喷嘴喉部的目标材料来制备，并将在真空室中通过光致电离飞行时间光谱进行探测。然后，对裸金属团簇的耗尽和产品生长的测量提供了金属团簇的化学反应率作为大小和组成的函数。将使用双光子电离、激光诱导荧光和受激发射光谱来测量各种金属和半导体二聚体和三聚体的键长、振动频率和术语符号。

This research, part of the Experimental Physical Chemistry Program, will entail spectroscopic studies of small metal and semiconductor molecules, and reactivity studies of metal clusters as functions of size and composition. These studies will contribute towards the development of a unified theory of metal/semiconductor electronic structure which can account for the variation in physical and chemical properties with size. Clusters will be prepared by laser vaporization of a target material in the throat of a pulsed supersonic nozzle, and will be detected in a vacuum chamber by photoionization time-of-flight spectrometry. Measurements of the depletion of bare metal clusters and growth of products then provide chemical reactivity rates for metal clusters as functions of size and composition. Two-photon ionization, laser induced fluorescence, and stimulated emission spectroscopies will be employed to measure bond lenghts, vibrational frequencies, and term symbols of various metal and semiconductor dimers and trimers.