Microwave Spectroscopy Measurements of Structures and Electronic Properties of Transition Metal Complexes

在化学部实验物理化学项目的资助下，PI将利用微波光谱技术研究过渡金属络合物和氢键络合物的转动光谱。测量将使用亚利桑那大学建造的脉冲光束傅里叶变换光谱仪系统进行。将构建一种带有放电区的新喷嘴系统来处理自由基。将对获得的数据进行分析，以确定三维、气相结构和其他相互作用参数。这项工作的总体目标包括：a)双核过渡金属络合物的结构和四极耦合系数；b)过渡金属化合物的弱结合络合物(催化反应的中间体模型)；c)氢键碱基类似物；d)参与甲基迁移反应的络合物的结构；以及e)有机金属自由基和反应产物的结构。测量的气相结构没有晶体堆积扭曲或溶剂效应，可以直接与自由分子的理论计算进行比较。将进行量子力学(DFT)计算，以补充所做的实验工作。研究生和本科生将参与这项研究。这项工作的结果将有利于化学工业，因为化学工业使用过渡金属催化剂生产化学产品，以及研究生物系统，如许多酶和生命系统中涉及过渡金属络合物的运输蛋白质，而氢键碱基对相互作用的细节可能在DNA化学中有用。

In this project, funded by the Experimental Physical Chemistry Program of the Chemistry Division, the PI will study the rotational spectra of transition metal complexes and hydrogen-bonded complexes by microwave spectroscopy. Measurements will be made with a pulsed-beam Fourier-transform spectrometer system constructed at the University of Arizona. A new nozzle system with an electric discharge region will be constructed to work on radicals. The data obtained will be analyzed to determine three-dimensional, gas-phase structures, and other interaction parameters. The overall objectives of this work include the determination of the structures and quadrupole coupling coefficients for: a) dinuclear transition metal complexes; b) weakly-bound complexes with transition metal compounds (models for intermediates in catalyzed reactions); c) hydrogen-bonded base pair analogs; d) structures of complexes involved in methyl migration reactions, and e) structures of organometallic radicals and reaction products. The measured gas-phase structures, which are free from crystal packing distortions or solvent effects, can be directly compared with the theoretical calculations for free molecules. Quantum mechanical (DFT) calculations will be carried out to complement the experimental work done. Graduate and undergraduate students will participate in this research. The results of this work will be of benefit to the chemical industry, which uses transition metal catalysts in the production of chemical products, as well as for the study of biological systems such as many enzymes and transport proteins in living systems that involve transition metal complexes, while details of hydrogen-bonded base pair interactions may be useful in DNA chemistry.