High resolution spectroscopy of radical complexes in the visible and ultraviolet regions, and determination of their intermolecular potentials

可见光和紫外区自由基配合物的高分辨率光谱及其分子间势的测定

基本信息

批准号：
05640559
负责人：
ENDO Yasuki
金额：
$ 1.47万
依托单位：
The University of Tokyo
依托单位国家：
日本
项目类别：
Grant-in-Aid for General Scientific Research (C)
财政年份：
1993
资助国家：
日本
起止时间：
1993 至 1994
项目状态：
已结题

项目摘要

The present research project intended to study radical complexes by means of a laser induced fluorescence spectroscopic technique using a Nd-YAG pumped tunable dye laser system combined with a pulsed-discharge-nozzle. Especially, by utilizing a frequency doubled dye laser we were able to observe LIF spectra of a rare gas-OH complex in the near UV region, which has been studied extensively. We have produced the OH radical in the supersonic jet by discharging water diluted in Ar.Spectra of Ar-OH were observed with a good signal to noise ratio between much stronger OH monomer lines, by carefully adjusting the nozzle dimensions and discharge conditions. Since we have confirmed that our system is capable to observe LIF spectra of a radical complex, we have started to search a new system by discharging various parent molecules diluted in rare gases. So far, we were able to observe monomer radicals C_2, C_3, CN,CCN etc. fairly strongly, and are continuing the search for spectra of complexes containing these short lived radical species.Along with these experimental studies, we have developed a program system to analyze the large amplitude motion of the radical complexs, where energy levels are far more complicated than those of complexes with closed shell molecules, since the radicals usually have an unpaired electron and its spin and/or orbital angular momenta couple with the large amplitude motion. We were able to explain the observed spectral patterns in the case of the rare gas-OH complexes. Especially, we have accurately treated the hyperfine interaction under the large amplitude motion, and have shown that it is possible to derive information for the intermoleclular potential from the observed hyperfine patterns.

本研究项目旨在通过激光诱导荧光光谱技术研究自由基配合物，该技术使用 Nd-YAG 泵浦可调谐染料激光系统与脉冲放电喷嘴相结合。特别是，通过利用倍频染料激光器，我们能够在近紫外区域观察稀有气体-OH络合物的LIF光谱，该光谱已被广泛研究。我们通过排放在 Ar 中稀释的水，在超音速射流中产生 OH 自由基。通过仔细调整喷嘴尺寸和排放条件，观察到 Ar-OH 的光谱，在更强的 OH 单体谱线之间具有良好的信噪比。由于我们已经确认我们的系统能够观察自由基复合物的 LIF 光谱，因此我们开始通过释放稀释在稀有气体中的各种母体分子来寻找新系统。到目前为止，我们已经能够相当强地观察到单体自由基C_2、C_3、CN、CCN等，并且正在继续寻找包含这些短命自由基物种的配合物的光谱。除了这些实验研究之外，我们还开发了一个程序系统分析自由基配合物的大幅运动，其中能级比具有闭壳分子的配合物复杂得多，因为自由基通常具有不成对的电子，其自旋和/或轨道角动量与大幅运动耦合。我们能够解释在稀有气体-OH 复合物中观察到的光谱模式。特别是，我们准确地处理了大幅度运动下的超精细相互作用，并表明可以从观察到的超精细图案中获取分子间势的信息。