TY - JOUR

T1 - Low-dimensional structural units in amine-templated uranyl oxoselenates(VI)

T2 - Synthesis and crystal structures of [C3H 12N2][(UO2)(SeO4)2(H 2O)2](H2O)

AU - Krivovichev, Sergey V.

AU - Kahlenberg, Volker

PY - 2005/9/30

Y1 - 2005/9/30

N2 - The crystals of four amine-templated uranyl oxoselenates(VI), [C 3H12N2][(UO2)(SeO4) 2(H2O)2](H2O) (1), [C 5H16N2]2[(UO2)-(SeO 4)2(H2O)](NO3)2 (2), [C4H12N][(UO2)(SeO4)(NO 3)] (3), and [C4H14N2][(UO 2)(SeO4)2(H2O)] (4) were prepared by evaporation from aqueous solution of uranyl nitrate, selenic acid and the respective amine. The crystal structures of all four compounds have been solved by direct methods from X-ray diffraction data. The structure of 1 (triclinic, P1, a = 7.5611(16), b = 7.7650(17), c = 12.925(3) Å, α = 94.605(18), β = 94.405(17), γ = 96.470(17)°, V = 748.8(3) Å3, R1 = 0.029 for 2769 unique observed reflections) is based upon 0D-units of the composition [(UO2) 2(SeO4)4(H2O)4] 4-. These discrete units are composed from two pentagonal [UO 7]8- bipyramids linked via [SeO4]2- tetrahedra and are unknown in structural chemistry of uranium so far. The structure of 2 (monoclinic, C2/c, a = 28.916(5), b = 8.0836(10), c = 11.9856(16) Å, β = 110.909(11)°, V = 2617.1(6) Å3, R 1 = 0.035 for 2578 unique observed reflections) contains [(UO 2)(SeO4)2(H2O)]2- chains of corner-sharing pentagonal [UO7]8- bipyramids and [SeO4]2- tetrahedra. The chains run parallel to the c axis and are arranged into layers parallel to (100). In the structure of 3 (monoclinic, C2/m, a = 21.244(5), b = 7.1092(11), c = 8.6581(18) Å, β = 97.693(17)°, V = 1295.8(4) Å3, R1 = 0.027 for 1386 unique observed reflections), pentagonal [UO7]8- bipyramids share corners with three [SeO4]2- tetrahedra each and an edge with a [NO3]- anion to form [(UO 2)(SeO4)(NO3)]- chains parallel to the b axis. In the structure of 4 (triclinic, P1, a = 6.853(2), b = 10.537(3), c = 10.574(3) Å, α = 99.62(3), β = 94.45(3), γ = 100.52(3)°, V = 735.6(4) Å3, R1 = 0.045 for 2713 unique observed reflections), one symmetrically independent pentagonal [UO 7]8- bipyramid shares corners with four [SeO 4]2- tetrahedra to form the [(UO2)(SeO 4)2(H2O)]2- chains parallel to the a axis. A comparison to related uranyl compounds is given.

AB - The crystals of four amine-templated uranyl oxoselenates(VI), [C 3H12N2][(UO2)(SeO4) 2(H2O)2](H2O) (1), [C 5H16N2]2[(UO2)-(SeO 4)2(H2O)](NO3)2 (2), [C4H12N][(UO2)(SeO4)(NO 3)] (3), and [C4H14N2][(UO 2)(SeO4)2(H2O)] (4) were prepared by evaporation from aqueous solution of uranyl nitrate, selenic acid and the respective amine. The crystal structures of all four compounds have been solved by direct methods from X-ray diffraction data. The structure of 1 (triclinic, P1, a = 7.5611(16), b = 7.7650(17), c = 12.925(3) Å, α = 94.605(18), β = 94.405(17), γ = 96.470(17)°, V = 748.8(3) Å3, R1 = 0.029 for 2769 unique observed reflections) is based upon 0D-units of the composition [(UO2) 2(SeO4)4(H2O)4] 4-. These discrete units are composed from two pentagonal [UO 7]8- bipyramids linked via [SeO4]2- tetrahedra and are unknown in structural chemistry of uranium so far. The structure of 2 (monoclinic, C2/c, a = 28.916(5), b = 8.0836(10), c = 11.9856(16) Å, β = 110.909(11)°, V = 2617.1(6) Å3, R 1 = 0.035 for 2578 unique observed reflections) contains [(UO 2)(SeO4)2(H2O)]2- chains of corner-sharing pentagonal [UO7]8- bipyramids and [SeO4]2- tetrahedra. The chains run parallel to the c axis and are arranged into layers parallel to (100). In the structure of 3 (monoclinic, C2/m, a = 21.244(5), b = 7.1092(11), c = 8.6581(18) Å, β = 97.693(17)°, V = 1295.8(4) Å3, R1 = 0.027 for 1386 unique observed reflections), pentagonal [UO7]8- bipyramids share corners with three [SeO4]2- tetrahedra each and an edge with a [NO3]- anion to form [(UO 2)(SeO4)(NO3)]- chains parallel to the b axis. In the structure of 4 (triclinic, P1, a = 6.853(2), b = 10.537(3), c = 10.574(3) Å, α = 99.62(3), β = 94.45(3), γ = 100.52(3)°, V = 735.6(4) Å3, R1 = 0.045 for 2713 unique observed reflections), one symmetrically independent pentagonal [UO 7]8- bipyramid shares corners with four [SeO 4]2- tetrahedra to form the [(UO2)(SeO 4)2(H2O)]2- chains parallel to the a axis. A comparison to related uranyl compounds is given.

KW - Crystal structures

KW - Selenium

KW - Uranium

KW - Uranyl oxoselenates

UR - http://www.scopus.com/inward/record.url?scp=25144444764&partnerID=8YFLogxK

U2 - 10.1002/zaac.200400505

DO - 10.1002/zaac.200400505

M3 - Article

AN - SCOPUS:25144444764

VL - 631

SP - 2352

EP - 2357

JO - Zeitschrift fur Anorganische und Allgemeine Chemie

JF - Zeitschrift fur Anorganische und Allgemeine Chemie

SN - 0044-2313

IS - 12

ER -