title: Coordination Modes of Americium in the Am2(C2O4)3(H2O)6·4H2O Oxalate: Synthesis, Crystal Structure, Spectroscopic Characterizations and Comparison in the M2(C2O4)3(H2O)6·nH2O (M = Ln, An) Series.
abstract: Americium oxalate single crystals, Am2(C2O4)3(H2O)6·4H2O, were prepared by in situ oxalic acid generation by slow hydrolysis of the diester. Their structure was determined by single-crystal X-ray diffraction and was solved by the direct methods and Fourier difference techniques. The structure (space group P21/c, a = 11.184(4) Å, b = 9.489(4) Å, c = 10.234(4) Å, β = 114.308(8)°, Z = 2) consists of layers formed by six-membered rings of actinide metals connected through oxalate ions. The americium atoms are nine-coordinated by six oxygen atoms from three bidentate oxalate ligands and three water molecules. The distances within the coordination sphere as well as infrared and Raman spectra of several isostructural lanthanide (Ce(III), Pr(III), Nd(III), Sm(III), Gd(III)) and actinide (Pu(III), Am(III)) oxalates were compared to evaluate the similarities and the differences between the two series.
authors.affiliation: Nuclear Energy Division, Marcoule, RadioChemistry & Processes Department, CEA , F-30207 Bagnols-sur-Cèze, France.
authors.forename: C
authors.initials: C
authors.lastname: Tamain
authors.affiliation: Nuclear Energy Division, Marcoule, RadioChemistry & Processes Department, CEA , F-30207 Bagnols-sur-Cèze, France.
authors.forename: B
authors.initials: B
authors.lastname: Arab-Chapelet
authors.affiliation: Unité de Catalyse et de Chimie du Solide, UCCS UMR CNRS 8181, ENSCL-USTL, Université Lille Nord de France , B.P. 90108, F-59652 Villeneuve d'Ascq Cedex, France.
authors.forename: M
authors.initials: M
authors.lastname: Rivenet
authors.affiliation: Institut de Chimie Séparative de Marcoule, UMR 5257, CEA/CNRS/ENSM, Université Montpellier 2 , F-30207 Bagnols-sur-Cèze, France.
authors.forename: X F
authors.initials: XF
authors.lastname: Legoff
authors.affiliation: Nuclear Energy Division, Marcoule, RadioChemistry & Processes Department, CEA , F-30207 Bagnols-sur-Cèze, France.
authors.forename: G
authors.initials: G
authors.lastname: Loubert
authors.affiliation: Nuclear Energy Division, Marcoule, RadioChemistry & Processes Department, CEA , F-30207 Bagnols-sur-Cèze, France.
authors.forename: S
authors.initials: S
authors.lastname: Grandjean
authors.affiliation: Unité de Catalyse et de Chimie du Solide, UCCS UMR CNRS 8181, ENSCL-USTL, Université Lille Nord de France , B.P. 90108, F-59652 Villeneuve d'Ascq Cedex, France.
authors.forename: F
authors.initials: F
authors.lastname: Abraham