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Molecular and Polymeric Uranyl and Thorium Complexes with Sulfonate‐Containing Ligands
Author(s) -
Thuéry Pierre
Publication year - 2014
Publication title -
european journal of inorganic chemistry
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.667
H-Index - 136
eISSN - 1099-0682
pISSN - 1434-1948
DOI - 10.1002/ejic.201301258
Subject(s) - chemistry , uranyl , carboxylate , denticity , sulfonate , sulfosalicylic acid , ligand (biochemistry) , medicinal chemistry , inorganic chemistry , pyridine , crystallography , hydrogen bond , crystal structure , stereochemistry , polymer chemistry , molecule , ion , organic chemistry , sodium , biochemistry , receptor
Abstract Six uranyl and one thorium(IV) cation complexes with ligands involving either only sulfonate or both sulfonate and carboxylate groups as complexing sites were obtained, mainly under hydrothermal conditions, and their crystal structures were determined. The uranyl ion complex with the 2‐sulfobenzoate (2‐SB 2– ) anion synthesized in the presence of pyridine, [pyH] 4 [(UO 2 ) 2 (2‐SB) 2 O] 2 · 4H 2 O ( 1 ), is a molecular, tetranuclear complex in which 2‐SB 2– is chelating through its two functional groups, while [Th(2‐SB) 2 (H 2 O) 3 ] · 2H 2 O ( 2 ) is a 1D polymer with monodentate sulfonate and bridging bidentate carboxylate groups. Complex [(UO 2 ) 3 K(4‐SB)O(OH) 3 (H 2 O) 1.5 ] · 0.5H 2 O ( 3 ), with the 4‐sulfobenzoate ligand, crystallizes as a 3D framework in which uranyl oxo/hydroxo 1D subunits are connected to one another by 4‐SB 2– and potassium cation bridges, the latter being involved in as much as five bonds with uranyl oxo groups (“cation–cation” bonds). Complex [UO 2 (5‐SSH 2 )(H 2 O) 3 ] 2 · 2(5‐SSH 2 ) · 3H 2 O ( 4 ), with 5‐sulfosalicylic acid (5‐SSH 3 ), is a dinuclear species in which the ligand is only coordinated through its bridging bidentate sulfonate group, an unusual occurrence. 5‐Sulfosalicylic acid undergoes partial desulfonation and carboxylation under hydrothermal conditions, yielding the heterometallic, tetranuclear complex [UO 2 Ni(5‐SHIPH)(4‐HIPH 2 )(bipy) 2 (H 2 O)] 2 · (4‐HIPH 3 ) ( 5 ), 5‐sulfonato‐2‐hydroxyisophthalic acid (5‐SHIPH 4 ) and 4‐hydroxyisophthalic acid (4‐HIPH 3 ) being generated in situ. The all‐sulfonate ligand 1,2‐ethanedisulfonate (EDS 2– ) acts as a divergent linker in both [UO 2 (EDS)(H 2 O) 3 ] ( 6 ) and [(UO 2 ) 2 (EDS)(OH) 2 (phen) 2 ] · 4H 2 O ( 7 ). 1D polymers are formed in both cases, the doubly monodentate EDS 2– ligand bridging isolated uranyl ions in 6 or hydroxo‐bridged uranyl dimers in 7 . Sulfonate coordination to the 5f cation is present in all these complexes but 5 , even in the absence of synergistic effects exerted by the stronger carboxylate ligating groups, and the variety of structures obtained in this as well as in previous work demonstrates that, together with the more investigated phosphonates, sulfonates are anions of great potential for the synthesis of actinide–organic coordination polymers and frameworks.