Uranium complex compounds analysis

In 1966, a catalyst based on a complex uranium antimonate system was developed and brought into commercial use (4, 87). Several physical methods of analysis were used in an attempt to clarify relationships between the structure and properties of the uranium antimonate system and its catalytic properties (20, 88, 89). X-Ray diffraction and infrared analysis demonstrated that the optimum selectivity for acrylonitrile formation coincided with the maximum concentration of the USb3O10 compound. The crystal structure of USb3O10 was shown to consist of layers of heavy atoms and oxygen ions alternated by layers of oxygen ions. Measurements by ESCA indicated that the surface layers contained U5+ and Sb5+ with intensities corresponding to the USb3O10 formula. 

It is necessary to mention that uranium p-diketonates were also obtained by a direct electrochemical procedure. Thus, the electrochemical oxidation of uranium leads to chelates of the type UL4 and U02L2 (LH = diketone) [14,343-347]. In addition to these complexes, the compound having composition UO2L2(HL)05 was also isolated [344] the structure showed in 974 (compare with 973) was proposed on IR spectroscopy data and, in our opinion, requires a more detailed analysis. 

The structures obtained by x-ray and neutron diffraction analysis of compound [U N(SiMe3)2 N(SiMe3)(SiMe2CF[2B(C2B(C6F5)3) ] reveal the electron deficiency of the uranium atom to be effectively compensated by the formation of multicenter bonds between the U atom and Si — CH2 units of the amido ligands the x-ray structure of [U C(Ph)(NSiMe3)2 2 r3-BH4 2] proves unequivocally the -coordination of the BH4 units [444]. The structure of a rare uranium (III) complex with a tripodal aromatic amine tm[(2,2 -bipyridin-6-yl)mcthyl]amine was reported [445]. 

Uranium(IV) complexes of A-type [XW9034] (Figure 4) anions have been reported but have received no structural characterization by NMR or X-ray diffraction. Based upon elemental analysis these compounds have been formulated as [(U0)3(GeW9034)2] [54] and [(U0)3(H20)6(PW9034)2] " [55] It is possible that these complexes are stucturally similar to... 

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