High Resolution Infrared Laser Spectroscopy of Metal-Containing Radicals

我们提出用一种新型激光光谱仪记录含金属的小分子多原子自由基的红外光谱。最近，一种大功率、单频、可广泛调谐的红外辐射源的出现，将彻底改变对瞬态含金属物质的研究。我们建议基于相对标准的技术，在金属流动反应器和激光汽化射流膨胀源中合成这些分子。其新颖之处在于利用红外光学双共振光谱和利用腔衰荡技术的直接红外吸收光谱对这些新的自由基进行超灵敏的检测。目标分子是参与催化和无机化学的更复杂物种的模型。电子结构、电子分布、振动频率和分子几何都可以通过高分辨率激光光谱学精确地研究，并与量子化学的预测相比较。量子化学预测的质量将被严格评估，这将最终导致更复杂系统的改进模型。

We propose to record infrared spectra of small metal-containing polyatomic free radicals using a new laser spectrometer. The very recent availability of a high-power, single frequency source of widely tunable infrared radiation will revolutionise the study of transient metal-containing species. We propose to synthesise these molecules in a metal flow reactor and in a laser vaporisation jet expansion source based on relatively standard techniques. The novelty comes from the ultrasensitive detection of these new free radicals by infrared-optical double resonance spectroscopy and by direct infrared absorption spectroscopy using the cavity ringdown technique. The target molecules are models for the more complex species involved in catalysis and inorganic chemistry. Electronic structure, electron distributions, vibrational frequencies and molecular geometry can all be studied with exquisite precision by high resolution laser spectroscopy and compared with the predictions of quantum chemistry. The quality of quantum chemical predictions will be critically assessed and this will ultimately lead to improved models for more complex systems.