Spectroscopic and Structural Elucidation of Uranium Dioxophenoxazine Complexes

Uranium derivatives of a redox-active, dioxophenoxazine ligand, (DOPOq)2UO2, (DOPOsq)­UI2(THF)2, (DOPOcat)­UI­(THF)2, and Cp*U­(DOPOcat)­(THF)2 (DOPO = 2,4,6,8-tetra-tert-butyl-1-oxo-1H-phenoxazin-9-olate), have been synthesized from U­(VI) and U­(III) starting materials. Full characterization of these species show uranium complexes bearing ligands in three different oxidation states. The electronic structures of these complexes have been explored using 1H NMR and electronic absorption spectroscopies, and where possible, X-ray crystallography and SQUID magnetometry.