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.
