Fluoro complexes of hexavalent uranium—IV Complexes of the series [UO2F3]− and [(UO2)2F5]−

Abstract The thermogravimetric studies of various salts of the ion [UO 2 F 3 ] − with organic basic cations have been made. By the pyrolysis of the salts with α-picoline, quinoline, 2,2′-dipyridyl and anthranilic acid, compounds of the type BH[(UO 2 ) 2 F 5 ] have been isolated. Similar salts with dimethyl aniline, cis - and trans -[Co(NH 3 ) 4 F 2 ] + and also the quinoline compound were obtained by direct precipitation of uranyl fluoride with the organic bases or with salts containing the complex cations in dilute HF medium. The conductivities and the solubilities of the salts and also of the salts belonging to the series [UO 2 F 3 ] − have been determined. A free acid formulated as H[UO 2 F 3 ].H 2 O has been isolated by reacting uranium trioxide with aqueous HF. It has been characterised by conductivity, and pH measurement of dilute solutions, potentiometric titration with alkali, determination of dissociation constant, thermogravimetric analysis and by a comparison of these results with those of UO 2 F 2 .2H 2 O.