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Two new double thorium oxalates with sodium ions have been prepared and characterized by using scanning electron microscopy/energy-dispersive spectroscopy (SEM/EDS), Raman spectroscopy and single-crystal X-ray diffraction. The crystal structure of Na4[Th(C2O4)4] ·5.5H2O ( 1) contains infinite chains, [Th(μ2-C2O4)2(C2O4)3] n4 n-, with three terminating bidentate and two bridging tetradentate oxalate ligands. The crystal structure of Na10[Th2(C2O4)9] ·15H2O ( 2) comprises unique dimers, [Th2(μ2-C2O4)(C2O4)8]10-, with Th atoms being coordinated by five oxalato ligands, four terminating bidentate and one bridging tetradentate. The structure is the first dimer of tetravalent actinide oxalato complexes. The spectroscopic results are in good agreement with the crystal structures. [ABSTRACT FROM AUTHOR]

Three neodymium (Nd) coordination polymers with propionate, succinate and mixed succinate–oxalate ligands have been synthesized and structurally characterized. Nd 2 (C 3 H 5 O 2 ) 6 (H 2 O) 3 ·3H 2 O ( 1 ) has a 1D polymeric structure built with both ninefold and ten-fold coordinated neodymium polyhedra linked through μ 2 -bridging propionate ligands. Nd 2 (C 4 H 4 O 4 ) 3 (H 2 O) 2 ( 2 ) has a 3D polymeric structure constructed with two distinct ninefold coordinated neodymium polyhedra linked through three types of succinate ligands, two in μ 4 - and one in μ 3 -coordination modes. Nd 2 (C 4 H 4 O 4 ) 2 (C 2 O 4 )(H 2 O) 4 ·3H 2 O ( 3 ) is built with two types of ten-fold coordinated neodymium polyhedra linked through μ 4 -succinate ligands into 2D undulating layers which are further connected through μ 2 -oxalate ligands forming a 3D network with channels. Their vibrational modes and thermal stabilities have been further investigated. [ABSTRACT FROM AUTHOR]

Great effort has been made to synthesize larger uranyl peroxide clusters whilst the understanding of the basic construction units for these clusters still needs to be further explored. Two small uranyl peroxide clusters stabilized by simple dicarboxylate ligands have been synthesized and characterized. Na 10 [(UO 2 )(O 2 )(C 3 H 2 O 4 )] 5 ·20H 2 O ( 1 ) has a pentagonal ring stabilized by malonate and [Na 4 K 2 (UO 2 ) 2 (O 2 )(C 2 O 4 ) 4 ]·6H 2 O ( 2 ) has a dimer stabilized by oxalate. Cation-cation interactions between uranyl and alkali metal ions exist in both 1 and 2 , leading to the observation of elongated U O −yl bonds. Vibrational modes of uranyl ion, peroxide and malonate/oxalate ligands have been confirmed by Raman spectroscopy. The presence of malonate ligands prevents the pentagonal uranyl peroxide rings further assembling into larger clusters whilst the excess oxalate ligands inhibit the dimers further linking to nearby uranyl centers. [ABSTRACT FROM AUTHOR]

Four dysprosium (Dy) single carboxylates, a formate, a propionate, a butyrate and an oxalate have been synthesized and structurally characterized. The structure of Dy(HCO 2 ) 3 ( 1 ) contains nine-fold coordinated Dy polyhedra in perfect tricapped trigonal prisms. They are linked through trigonal O atoms forming 1D pillars which are further linked together through tricapped O atoms into a 3D pillared metal organic framework. The network structure is stable up to 360 °C. The structure of [Dy 2 (C 2 O 4 ) 3 (H 2 O) 6 ]·2.5H 2 O ( 2 ) contains nine-fold coordinated Dy polyhedra linking together through μ 2 -bridging oxalate anions into a 2D hexagonal layered structure. Both [Dy 2 (Pr) 6 (H 2 O) 4 ]·(HPr) 0.5 ( 3 ) [Pr=(C 2 H 5 CO 2 ) −1 ] and [Dy 2 (Bu) 6 (H 2 O) 4 ] ( 4 ) [Bu=(C 3 H 7 CO 2 ) −1 ] have similar di-nuclear structures. The Raman vibration modes of the complexes have been investigated. [ABSTRACT FROM AUTHOR]