Cation Effects on the Formation of the One-Dimensional Uranyl Iodates A2[(UO2)3(IO3)4O2] (A=K, Rb, Tl) and AE[(UO2)2(IO3)2O2] (H2O) (AE=Sr, Ba, Pb)

✍ Scribed by Amanda C. Bean; Thomas E. Albrecht-Schmitt

• Publisher: Elsevier Science
• Year: 2001
• Tongue: English
• Weight: 436 KB
• Volume: 161
• Category: Article
• ISSN: 0022-4596
• DOI: 10.1006/jssc.2001.9357

✦ Synopsis

The reactions of UO 3 and I 2 O 5 with RbCl, TlCl, SrCl 2 , or Pb(NO 3 ) 2 at 2003 3C for 3 days in aqueous media result in the formation of A 2 [(UO 2 ) 3 (IO 3 ) 4 O 2 ] (A ‫؍‬ Rb (1), Tl (2)) and AE[(UO 2 ) 2 (IO 3 ) 2 O 2 ](H 2 O) (AE ‫؍‬ Sr (3), Pb, (4)). Compounds 1 and 2 are isostructural with K 2 [(UO 2 ) 3 (IO 3 ) 4 O 2 ], which has been prepared by similar methods. These compounds are composed of 1 R [(UO 2 ) 3 (IO 3 ) 4 O 2 ] 2! chains built from the edgesharing of UO 7 pentagonal bipyramids and UO 6 octahedra. Compounds 3 and 4 are isostructural with Ba[(UO 2

ribbons formed from the edge-sharing of distorted UO 7 pentagonal bipyramids. The iodate groups in these compounds adopt both bridging and monodentate binding modes and further serve to terminate the edges of the uranium oxide chains. The alkali metal, alkaline-earth metal, and main group cations separate the chains or ribbons in these compounds forming contacts with terminal oxygen atoms from the iodate ligands.