Thorium Oxo‐Clusters as Building Blocks for Open Frameworks. Issue 53 (23rd August 2018)

• Record Type: Journal Article
• Authors: Falaise, Clément; Kozma, Karoly; Nyman, May
• Is Part Of: Chemistry. Volume 24:Issue 53(2018)
• Page Start: 14226
• Page End: 14232
• Publication Date: 2018-08-23
• Subjects: metal-oxo clusters -- open inorganic frameworks -- SAXS -- sulfate -- thorium -- X-ray diffraction; Chemistry -- Periodicals; 540
• DOI: 10.1002/chem.201802671
• Languages: English
• ISSNs: 0947-6539

Abstract

Abstract: Fundamental understanding of tetravalent actinide chemistry is essential to optimize many steps of the nuclear fuel cycle, as well as to predict actinide speciation in the environment. Herein, we report synthesis and structure of three open inorganic frameworks composed of Th 4+ ‐oligomers and sulfate anions. The compounds [Th10 O4 (OH)8 (SO4 )12 (H2 O)18 ]⋅ 28 H2 O (1 ), [Th9 O4 (OH)5 (SO4 )12 (H2 O)18 ]⋅ 1 TMA⋅ 18 H2 O (2 ), and [Th8.5 O4 (OH)4 (SO4 )12 (H2 O)18 ]⋅ 2 TMA⋅ n H2 O (3 ) were obtained by slow evaporation of aqueous Th 4+ ‐SO4 2− solutions, with variable SO4 2− :Th 4+ ratios (SO4 2− :Th 4+ =1:1, 1.5:1 and 2:1 for1, 2, and3 ; TMA=tetramethylammonium). The structure of1 features a neutral open framework architecture with two interpenetrating networks, built from Th6 O4 (OH)4 12+ hexamers and Th2 (OH)2 6+ dimers, linked by sulfate anions. The complex anionic framework of2 is built from hexamers, dimers, and monomers, with charge‐balancing TMA cations. Compound3 is very similar to2, but it is constructed only from hexamers and monomers. Small angle X‐ray scattering (SAXS) of the reaction solutions reveals pre‐assembled hexamer building units in the presence of sulfate, and underlines the key role of the sulfate‐oxoanion ligand on thorium polymerization processes. Abstract : Avengers assemble : Simple aqueous solutions of thorium plus sulfate, with pH control, yields thorium‐oxo monomers, dimers, and hexamers that self‐assemble into open frameworks, including a rare all‐inorganic interpenetrating network.