ChemInform Abstract: SEVEN-COORDINATE DISTORTED C3V-CAPPED TRIGONAL-PRISMATIC EUROPIUM(II). CRYSTAL STRUCTURE OF HYDRATED EUROPIUM(II)-EXCHANGED SODIUM ZEOLITE A, EU5NA2-A

1978 ◽  
Vol 9 (42) ◽  
Author(s):  
R. L. FIROR ◽  
K. SEFF
Author(s):  
Avijit Kumar Paul

The mixed-metal sulfate, KEu(SO4)2·H2O, has been obtained as a new polymorph using hydrothermal conditions. The crystal structure is isotypic with NaCe(SO4)2·H2O and shows a three-dimensional connectivity of the tetrahedral sulfate units with EuIII and KI ions. Tricapped trigonal–prismatic EuO9 units and square-antiprismatic KO8 units link the SO4 tetrahedra, building the three-dimensional structure. Topological analysis reveals the existence of two nodes with 6- and 10-connected nets. The compound was previously reported [Kazmierczak & Höppe (2010). J. Solid State Chem. 183, 2087–2094] in the monoclinic space group P21/c with a similar structural connectivity and coordination environments to the present compound.


2013 ◽  
Vol 69 (12) ◽  
pp. 1503-1508 ◽  
Author(s):  
Thazhe Kootteri Prasad ◽  
M. V. Rajasekharan

Three three-dimensional coordination polymers,viz.poly[[diaqua-μ4-oxydiacetato-di-μ4-sulfato-dipraseodymium(III)] hemihydrate], [Pr2(C4H4O5)(SO4)2(H2O)2]·0.5H2O, (I), poly[[diaquadi-μ3-oxydiacetato-μ3-sulfato-dineodymium(III)] 1.32-hydrate], [Nd2(C4H4O5)2(SO4)(H2O)2]·1.32H2O, (II), and poly[[diaquadi-μ3-oxydiacetato-μ3-sulfato-disamarium(III)] 1.32-hydrate], [Sm2(C4H4O5)2(SO4)(H2O)2]·1.32H2O, (III), were obtained by hydrothermal reactions of the respective lanthanide oxides and ZnSO4with oxydiacetic acid (odaH2). The Nd3+and Sm3+compounds form isomorphous crystal structures in which the lanthanide cations are nine-coordinate, having a tricapped trigonal prismatic coordination. The Pr3+compound has an entirely different crystal structure in which two types of coordination polyhedra are observed,viz.nine-coordinate (trigonal prism) and ten-coordinate (bicapped square antiprism). The sulfate anions show various coordination modes, one of which has only rarely been observed crystallographically to date.


2017 ◽  
Vol 73 (8) ◽  
pp. 1121-1124 ◽  
Author(s):  
NDiaye Mbossé Gueye ◽  
Dieng Moussa ◽  
Elhadj Ibrahima Thiam ◽  
Aliou Hamady Barry ◽  
Mohamed Gaye ◽  
...  

In the title compound, [Tb(C2H3O2)2(C11H10N4)(H2O)2]NO3·H2O, the Tb3+ ion is nine-coordinated in a distorted tricapped trigonal-prismatic geometry by the three N atoms of the tridentate 1-(pyridin-2-ylmethylidene)-2-(pyridin-2-yl)hydrazine ligand, four carboxylate O atoms of two chelating acetate groups and two O atoms of the coordinating water molecules. The organic hydrazine ligand is disordered over two orientations with a refined occupancy ratio of 0.52 (3):0.48 (3). All bond lengths in the coordination environment of the Tb3+ ion are slightly larger than those observed in the isostructural Y3+ and Er3+ complexes. In the crystal, the complex cations are linked by pairs of O—H...O hydrogen bonds into dimers. These dimers, nitrate anions and non-coordinating water molecules are joined by O—H...O and N—H...O hydrogen bonds into a three-dimensional structure.


2003 ◽  
Vol 58 (11) ◽  
pp. 1112-1116 ◽  
Author(s):  
Kurt O. Kleppa ◽  
Norbert A. Harringer ◽  
Hubert Preßlinger

Abstract Lustrous needle shaped prismatic single crystals of the new compound Ca10V5.2Fe0.8O24 were obtained out of a sample with nominal composition Ca2Fe1.6V0.4O5 prepared at 1400 °C. The crystals are opaque and stable to humid air. Ca10V5.2Fe0.8O24 crystallizes with a new structure type, space group Pnma with a = 6.803(3), b = 16.015(8), c = 10.418(7)Å , Z = 2, R = 0.041. The crystal structure is characterized by two mononuclear tetrahedral species, MO4, which differ significantly from each other with respect to their M-O bond lengths. One with an average bond distance of 1.709(8)Å represents an orthovanadate ion. The other with a significantly larger value d(M-O) = 1.744(6) Å corresponds to a mixed occupation of its centre according to [V0.8Fe0.2O4]3.5−. In the crystal structure the complex anions are arranged in separate sheets parallel to the (010) plane. They are separated from each other by three crystallographically independent Ca2+ ions which are each coordinated by 7 oxygen atoms in distorted pentagonal bipyramidal and trigonal prismatic configurations, respectively.


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