Vibrational Energy Dynamics in Solute/Solvent Clusters and Solute Dimers

Bernstein教授和Kelley教授在实验物理化学项目的支持下，合作研究了小溶质/溶剂团簇和溶质二聚体在超音速分子射流膨胀中形成的激发态的振动能量动力学。这些测量将有助于阐明在将初始能量重新分配到其他自由度中所涉及的各种无辐射过程的相对重要性。光激发将在溶质发色团的第一激发态中制备具有已知振动能量的团簇。振动动力学将通过皮秒光谱研究来监测抽运母团簇和预解产生的自由分子在特定振动水平上的上升和衰减时间。测量将包括时间分辨发射、双色电离和双色受激发射泵浦。溶质发色团是芳杂嗪，溶剂包括氨、水、甲烷、氘化甲烷、氩气和四氟化碳。

Professors Bernstein and Kelley are supported by the Experimental Physical Chemistry Program in a collaborative study of vibrational energy dynamics in excited electronic states of small solute/solvent clusters and of solute dimers formed in a supersonic molecular jet expansion. These measurements will help elucidate the relative importance of various radiationless processes involved in redistributing the initial energy into other degrees of freedom. Optical excitation will prepare the clusters with known amounts of vibrational energy in the first excited singlet state of the solute chromophore. The vibrational dynamics will be monitored by picosecond spectroscopic studies of the rise and decay times of the population in specific vibronic levels of both the pumped parent cluster and the free molecule resulting from predissociation. Measurements will include time-resolved emission, two color ionization, and two color stimulated emission pumping. The solute chromophores will be aromatic azines, and the solvents will include ammonia, water, methane, deuterated methane, argon, and carbon tetrafluoride.