Photophysics of small molecules-in clusters and rare gas crystals-

目前国际科学研究计划的目标是研究低温稀有气体晶体中掺杂的小分子在强紫外光激光照射下的光物理和光化学行为，由Koda教授(东京大学)和Apkarian教授(加州大学欧文分校)合作1.为了获得未知的XES激发态及其发射的信息，研究了掺S化合物的Xe晶体在KrF准分子激光照射下的光物理行为。在Xe的自由晶体中，在248 nm的辐射下，OCS很容易解离。随着激光照射时间的延长，晶体中以346 nm为中心的广角发射增强，这被认为是晶体中XES电荷转移激基络合物的转变。记录了S原子的温度诱导迁移率：升温后，激基络合物的发射强度降低，伴随着S_2(B*X)发射带强度的增加。阿普卡里安实验室研究了掺杂在D_2晶体中的O_2的光物理行为，以获得有关以下方面的信息。它们是：O(单重态)与D_2在固体D_2中的反应性或缺失，O在O_2附近的旋光性，O和O_2在固体D_2中的扩散，以及它们与D_2.3的量子固体性质的关系。协作单个小组的研究人员相互访问，进行了良好的合作。

The objective of the present international scientific research program is to study the photopysical and photochemical behaviors of small molecules doped in low temperature rare gas crystals when they are irradiated by strong uv lasers, under the collaboration between the group of Prof.Koda (the University of Tokyo) and Prof.Apkarian (University of California, Irvine).1. Study in Koda's LaboratoryIn order to obtain information about the unknown XeS exciplex state and the emissions therefrom, the photophysical behavior of S-containing compounds doped in a Xe crystal under the irradiation of KrF excimer laser was investigated. In free standing crystals of Xe, OCS was found to readily dissociate upon irradiation at 248 nm. With the continuation of the laser irradiation, abroad emission centered at 346 nm was found to grow, which was assigned to the XeS charge transfer exciplex transition in the crystal. Temperature induced mobility of S atoms was documented : upon warm-up, the intensity of the exciplex emission decreased with concomitant increase of the S_2 (B*X) emission band intensity.2. Study in Apkarian's LaboratoryThe Photophysical behavior of O_2 doped in a D_2 crystal was studied in order to obtain informations concerning the following items. They are ; the reactivity or the lack thereof of O (singlet) with D_2 in solid D_2, the optical activity of O near O_2, diffusion of O and O_2 in solid D_2, and their relations to the character of the quantum solids of D_2.3. CollaborationThe researchers of individual groups visited the other group each other and good collaboration was performed.