Actinide structural studies. 12. 4,4'-Bipyridinium di-μ-hydroxo-bis[dinitratodioxouranate(VI)] monohydrate

Thiosemicarbazone Complexes of UraniumDedicated to Professor Joachim Strähle on the Ocassion of his 65th Birthday

“…The structure of the anion is given in Figure 1. These bond lengths are slightly shorter than those observed for the [UO 2 (NO 3 ) 2 (µ-OH)] 2 2Ϫ anions in their choline and bipyridinium salts (2.339(7) Ϫ 2.36(1) Å ) [7,8]. The uranium atoms are six-co-ordinate with the metal atoms in the centres of distorted hexagonal bipyramids.…”

“…Uranium dimers of this type have been described earlier as trimethyl-(hydroxyethyl)ammonium [7] and 4,4Ј-bipyridinium [8] salts. Consequently, no complex formation with the thiosemicarbazone is observed and only yellow plates of (H 2 APTSC) 2 -[UO 2 (NO 3 ) 2 (µ 2 -OH)] 2 · 2 H 2 O could be isolated.…”

Crystallization of Uranyl Salts from Dialkylimidazolium Ionic Liquids or Their Precursors

“…[24] In addition to hydrogen bonding a very short contact is observed in 4 [2.895(5) Å] and 5 [2.83(1) Å] between the axial oxygen atom, O1, and the nitrogen atom, N5, from the nitrate group coordinated to the uranyl center from adjacent anions in the columnar arrangement, probably as a consequence of the geometric constraints resulting from the very strong short contacts between O2 and H1O3 from the adjacent anions. Such interactions are not observed in compound 6.…”

Tetra-n-butylammonium di-μ-hydroxo-bis[dinitratodioxouranate(VI)]

“…The [UO 2 (NO 3 ) 2 (OH)] 2 group (and close relatives) are not uncommon in the coordination chemistry of the uranyl ion. The hydroxy complex can be found in compounds such as the cholinium complex (Viossat et al, 1983), the 4,4 0 -bipyridinium compound (Alcock & Flanders, 1987), the crown ether complex (Evans et al, 2002) Masci, 2002).…”