Uranyl mixed compounds of the dioxalate series

Shchelokov, R.N.; Mikhaǐlov, Yu. N.; Orlova, I. M.; Sergeev, Artem V.; Beyrahov, A.G.; Kanishcheva, A. S.; Lobanova, G. M.

doi:10.1016/s0020-1693(00)94540-7

Cited by 4 publications

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“…The ligand DCTA 4− is akin to EDTA 4− , and it would be interesting to compare the structures of the uranyl complexes formed by each of them, since they differ by the rigidity imposed by the cyclohexyl ring. Unfortunately, no uranyl complex with EDTA 4− could be obtained up to now under the present conditions, and the only crystal structure available is that of the centrosymmetric, bimetallic species [(UO 2 F 2 ) 2 (EDTA)] 4− , in which each uranyl ion is chelated by two carboxylate oxygen atoms and one nitrogen atom, the presence of terminal fluorine ligands preventing the formation of a coordination polymer . Bonding to the cyclohexyl ring prevents the two aminodicarboxylate groups in DCTA 4− to be as far apart from one another as those in EDTA 4− , and the formation of a centrosymmetric species is impossible.…”

Section: Discussionmentioning

confidence: 94%

“…Unfortunately, no uranyl complex with EDTA 4could be obtained up to now under the present conditions, and the only crystal structure available is that of the centrosymmetric, bimetallic species [(UO 2 F 2 ) 2 (EDTA)] 4-, in which each uranyl ion is chelated by two carboxylate oxygen atoms and one nitrogen atom, the presence of terminal fluorine ligands preventing the formation of a coordination polymer. 34 Bonding to the cyclohexyl ring prevents the two aminodicarboxylate groups in DCTA 4to be as far apart from one another as those in EDTA 4-, and the formation of a centrosymmetric species is impossible. Although they are attached to a rigid platform, the acetate arms have sufficient conformational freedom to allow (together with the directional freedom associated to monodentate bonding) the formation of polymers of variable dimensionality and architecture.…”

Section: Discussionmentioning

confidence: 99%

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Uranyl−Organic Assemblies with Acetate-Bearing Phenyl- and Cyclohexyl-Based Ligands

Thuéry

2010

Crystal Growth & Design

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Six novel complexes formed under hydrothermal conditions by uranyl ions with three ligands comprising a rigid phenyl-or cyclohexyl-containing platform, and two to four acetate arms have been obtained. 1,3,5-Benzenetriacetic acid (H 3 BTA) yielded the complex [NMe 4 ][UO 2 (BTA)] 3 H 2 O (1), in which the structure-directing counterion induces a twodimensional, bilayer-type structure different from that previously reported, with both the tris-chelating ligand and the metal ion as trigonal nodes. Two complexes were obtained with 1,2-phenylenedioxydiacetic acid (Complex 2 is a simple, ribbon-like, one-dimensional polymer, while 3 is a nanotubular assembly built around the hydrogen-bonded, structure-directing counterions. Three complexes were obtained with trans-1,2-diaminocyclohexane-N,N,N 0 ,N 0 -tetraacetic acid (H 4 DCTA), a polyaminopolycarboxylic acid, with different bases, 5), and [UO 2 Na(HDCTA)(H 2 O)] ( 6). The nitrogen atoms are not coordinated, both of them (4) or only one (5 and 6) being protonated, and the carboxylic/ate groups are monodentate, except for one chelating in 6 and one nonbonding in 4. These differences in bonding result in various assemblies, onedimensional in 4 and two-dimensional in 5 and 6. The layers in 5 are strongly corrugated, with the cyclohexyl groups pointing on either side, and their packing displays oval-shaped channels, while the layers in 6 are planar, with the cyclohexyl groups located on one side, and further assembled into dimeric units by the disordered sodium ions. These are the first crystal structures of actinide ion complexes with both H 2 PDDA and H 4 DCTA.

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Section: Discussionmentioning

confidence: 94%

Section: Discussionmentioning

confidence: 99%

Uranyl−Organic Assemblies with Acetate-Bearing Phenyl- and Cyclohexyl-Based Ligands

Thuéry

2010

Crystal Growth & Design

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“…Extended X-ray absorption fine structure (EXAFS) spectroscopy is a technique of choice to gain structural information on such systems, and it has been used to characterize the complexes formed by tetravalent actinide ions with nitrilotriacetic acid in aqueous solution, in association with spectrophotometric determination of stability constants and quantum chemical calculations, and also the complexes formed by thorium(IV) with ethylenediaminetetraacetic acid . However, there is at present a dearth of structural data determined in the solid state since a search for crystal structures in the Cambridge Structural Database (CSD, Version 5.31) gives only some examples of complexes of uranyl ions with iminodiacetic, nitrilotriacetic, ethylenediaminediacetic, and ethylenediaminetetraacetic acids, and of neptunyl ions with N -methyliminodiacetic acid, while the only ones with tetravalent actinide ions are the uranium(IV) complexes with nitrilotriacetic and ethylenediaminetetraacetic acids and the thorium(IV) complex with the latter ligand . Only one thorium(IV) complex in this family has thus been crystallographically characterized up to now, which is a molecular species with the cation bound to four oxygen and two nitrogen atoms from the aminopolycarboxylate ligand and to three fluorine atoms.…”

Section: Introductionmentioning

confidence: 99%

Solid State Structure of Thorium(IV) Complexes with Common Aminopolycarboxylate Ligands

Thuéry

2011

Inorg. Chem.

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The crystal structures of the complexes formed by reaction of thorium(IV) nitrate with iminodiacetic acid (H(2)IDA), nitrilotriacetic acid (H(3)NTA), and ethylenediaminetetraacetic acid (H(4)EDTA) under hydrothermal conditions are reported. In [Th(HIDA)(2)(C(2)O(4))]·H(2)O (1), the metal atom is chelated by two carboxylate groups from two HIDA(-) anions and by two oxalate ligands formed in situ; two additional oxygen atoms from two more HIDA(-) anions complete the ten-coordinate environment of bicapped square antiprismatic geometry. The uncoordinated nitrogen atom is protonated and involved in hydrogen bonding. Two different ligands are present in [Th(NTA)(H(2)NTA)(H(2)O)]·H(2)O (2), one of them being a O(3),N-chelating trianion which acts also as a bridge toward two neighboring metal ions, and the other being a bis-monodentate bridging species with an uncoordinated carboxylic arm and a central ammonium group. An aqua ligand completes the nine-coordinated, capped square antiprismatic metal environment. The EDTA(4-) anion in [Th(EDTA)(H(2)O)]·2H(2)O (3) is chelating through one oxygen atom from each carboxylate group and the two nitrogen atoms, as in a previously reported molecular complex. Two carboxylate groups are bridging, which, with the addition of an aqua ligand, gives a capped square antiprismatic coordination polyhedron. Aminopolycarboxylate ligands have been much investigated in relation with actinide decorporation and nuclear wastes management studies, and the present results add to the structural information available on their complexes with thorium(IV), which has mainly been obtained up to now by extended X-ray absorption fine structure (EXAFS) spectroscopy. In particular, the bridging (non-chelating) coordination mode of H(2)NTA(-) is a novel feature in this context. All three complexes crystallize as two-dimensional assemblies and are thus novel examples of thorium-organic coordination polymers.

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“…EDTA can affect the sorption , and redox , behaviors of uranium by forming stable complexes and thus impacts the mobility of uranium in the environment. Only limited crystal structures of these complexes have been isolated, , although structures of transition metal and lanthanide based complexes containing EDTA have been widely investigated. − In the current study, the first four uranyl peroxide compounds containing EDTA groups were isolated and characterized from solutions containing hydrogen peroxide over a pH range of 5–7.…”

Section: Introductionmentioning

confidence: 99%

Expanding the Crystal Chemistry of Uranyl Peroxides: Four Hybrid Uranyl-Peroxide Structures Containing EDTA

et al. 2014

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The first four uranyl peroxide compounds containing ethylenediaminetetra-acetate (EDTA) were synthesized and characterized from aqueous uranyl peroxide nitrate solutions with a pH range of 5-7. Raman spectra demonstrated that reaction solutions that crystallized [NaK15[(UO2)8(O2)8(C10H12O10N2)2(C2O4)4]·(H2O)14] (1) and [Li4K6[(UO2)8(O2)6(C10H12O10N2)2(NO3)6]·(H2O)26] (2) contained excess peroxide, and their structures contained oxidized ethylenediaminetetraacetate, EDTAO2(4-). The solutions from which [K4[(UO2)4(O2)2(C10H13O8N2)2(IO3)2]·(H2O)16] (3) and LiK3[(UO2)4(O2)2(C10H12O8N2)2(H2O)2]·(H2O)18 (4) crystallized contained no free peroxide, and the structures incorporated intact EDTA(4-). In contrast to the large family of uranyl peroxide cage clusters, coordination of uranyl peroxide units in 1-4 by EDTA(4-) or EDTAO2(4-) results in isolated tetramers or dimers of uranyl ions that are bridged by bidentate peroxide groups. Two tetramers are bridged by EDTAO2(4-) to form octamers in 1 and 2, and dimers of uranyl polyhedra are linked through iodate groups in 3 and EDTA(4-) in 4, forming chains in both cases. In each structure the U-O2-U dihedral angle is strongly bent, at ∼140°, consistent with the configuration of this linkage in cage clusters and other recently reported uranyl peroxides.

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Uranyl mixed compounds of the dioxalate series

Cited by 4 publications

References 0 publications

Uranyl−Organic Assemblies with Acetate-Bearing Phenyl- and Cyclohexyl-Based Ligands

Uranyl−Organic Assemblies with Acetate-Bearing Phenyl- and Cyclohexyl-Based Ligands

Solid State Structure of Thorium(IV) Complexes with Common Aminopolycarboxylate Ligands

Expanding the Crystal Chemistry of Uranyl Peroxides: Four Hybrid Uranyl-Peroxide Structures Containing EDTA

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