Uranium magnetic susceptibility

Uranium metal is weaMy paramagnetic, with a magnetic susceptibility of 1.740 X 10 A/g at 20°C, and 1.804 x 10 A/g (A = 10 emu) at 350°C (51). Uranium is a relatively poor electrical conductor. Superconductivity has been observed in a-uranium, with the value of the superconducting temperature, being pressure-dependent. This was shown to be a result of the fact that there are actually three transformations within a-uranium (37,52). 

Magnetic-susceptibility measurements showed the presence of UF4 in heated samples. Ebert et al. (E14) reported a nominal stoichiometry CisUFg, magnetic-susceptibility measurements indicating partial reduction at room temperature, with 10% of the uranium species present as U(IV). Wide-line NMR demonstrated the presence of both U(VI) and U(IV). 

The general pattern of the UV/vis absorption spectra of all these complexes resembles that of (in perchloric acid), but apparently corresponding peaks are shifted by about 4% in frequency, very much the same as in the red UCU salts. Data on the magnetic susceptibilities and effective magnetic moments for the uranium in these complexes are conflicting. On the one hand, a series of rather low fiets... 

The first tris(pentamethylcyclopentadienyl) complex of uranium was synthesized in 50% yield by hydrogenation of tetramethylfulvene with Cp 2UH(dmpe) (Scheme 34) and characterized by common analytical methods (IR, H, 13C NMR, magnetic susceptibility and elemental analysis).89,89a... 

Measurement of magnetic susceptibility and electronic spectra of the cerium and uranium complexes verified the presence of the +4 oxidation state. 

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