Syntheses and optical and magnetic properties of tetrakis(di-n-propylamido)uranium(IV), tetrakis(di-n-butylamido)uranium(IV), tetrakis(di-n-propylamido)thorium(IV), and tetrakis(di-n-butylamido)thorium(IV), volatile liquid amides

The thorium and uranium alkylamides M[N(CH2CH2CH3)2]4 and M[N(CH2CH2CH2CH3)2]4 (M = Th and U) have been prepared and isolated. These extremely air-sensitive compounds are liquids at room temperature and distillable under high vacuum at temperatures less than 1000C. The proton magnetic resonance spectra, the optical spectra, and the temperature-dependent magnetic susceptibilities (T = 4.2 to 100 K) of the two uranium compounds are reported. The spectroscopic and magnetic properties of the uranium compounds are very similar to those of U(N(C2H5)2)4