ELECTRONIC SPECTRAL STUDIES OF SOME URANIUM(V) COMPOUNDS

The following solid compounds were prepared and characterized in inert atmospheres: MUCl6 (M = Rb and (n-C3H7)4N), both new compounds in regard to the cation present; UCl5-SOCl2; UCl5-PCl5; and UCl5-TCAC (TCAC = trichloroacrylyl chloride, Cl2C=CClCOCl), a new compound. In addition, solutions of UCl3 in CCl4 and SiCl4 were prepared. Infrared spectra were obtained. Electronic spectra in the near-ir and visible region were obtained for the MUCl6 compounds dissolved in SOCl2; for UCl5-TCAC dissolved in SOCl2, C6H6, CS2, and CCl4; for UCl5-SOCl2 dissolved in SOCl2 and CCl4; and for UCl5 in CCl4 and SiCl4. Electronic as well as vibronic band assignments have been made for these 5f1 electronic systems and several of the vibrational frequencies of the UCl6- species have been deduced from the electronic spectra. The first esr spectra for pure U(V) compounds, obtained with powdered samples, are reported, and the average g values are all 1.1. © 1968, American Chemical Society. All rights reserved.