EPR characterization of V(IV) complexes with and without an oxo group

INOR 8

Sandra S. Eaton, seaton@du.edu, Gareth R. Eaton, geaton@du.edu, and Alistair Fielding, afielding@du.edu. Department of Chemistry and Biochemistry, University of Denver, Denver, CO 80206-2436
EPR spectroscopy of vanadium(IV) complexes is a powerful tool for characterizing geometry and electronic structure. Most of the prior work on vanadium(IV) has focused on complexes that contain an oxo group. We will compare the CW and time-domain EPR properties of amavadin, in which the coordination sphere is N2O6 with no oxo groups, with properties of a series of complexes with oxo groups. Vanadium hyperfine splittings and g-values in fluid solution, and glassy rigid lattice, and spin-lattice relaxation rates between about 20 and 100 K, will be described. The temperature dependence of the relaxation rates reveals the mechanism of relaxation.