Ca10Ge16B6O51 and Cd12Ge17B8O58: two types of new 3D frameworks based on BO4 tetrahedra and 1D [Ge4O12]n chains

Two new acentric borogermanates, Ca(10)Ge(16)B(6)O(51) (Pba2) and Cd(12)Ge(17)B(8)O(58) (P4), have been successfully synthesized by high-temperature solid-state reactions of CaCO(3) (or CdCO(3)), GeO(2), and H(3)BO(3). Both structures display the same one-dimensional (1D) [Ge(4)O(12)](n) chains composed of GeO(4) tetrahedra and GeO(6) octahedra. In Ca(10)Ge(16)B(6)O(51), neighboring 1D [Ge(4)O(12)](n) chains are condensed into a two-dimensional (2D) [Ge(4)O(10.75)](n) layer via corner sharing, and such layers are further interconnected by "isolated" BO(4) tetrahedra and B(2)O(7) dimers into a three-dimensional (3D) framework, forming 1D tunnels of 5-, 6-, and 7-MRs along the c axis that are occupied by Ca(2+) cations. In Cd(12)Ge(17)B(8)O(58), neighboring 1D [Ge(4)O(12)](n) chains are interconnected into a [Ge(4)O(10.5)](n) open framework via corner sharing with large pores filled by big [Ge(B(2)O(7))(4)](28-) clusters, leading to formation of three types of 1D tunnels of 5-, 6-, and 7-membered rings (MRs) along the c axis which are occupied by the Cd(2+) cations. Both compounds are transparent in the range of 0.3-6.67 μm and exhibit very weak SHG responses.     

A germanium zeotype with a three-dimensional net of interconnected 14-, 12- and 12-ring channels. Ge13O26(OH)4[C6N2H16]2(H2O)1.5

Ge(13)O(26)(OH)(4)[C(6)N(2)H(16)](2)(H(2)O)(1.5) is a novel germanium zeotype built up from a new type of SBU; the SBU-13 is formed from polyhedra distributed in three shells. Its open 3D framework has a three-dimensional system of intersecting channels, where the 14-ring channels are lined with OH(-) anions.     

Two three-dimensional {V16Ge4}-based open frameworks stabilized by diverse types of Co(II)-amine bridges and magnetic properties

Two novel three-dimensional (3D) extended vanadogermanate-based frameworks, [Co(pdn)(2)](3)[Co(2)(pdn)(4)][V(16)Ge(4)O(44)(OH)(2)(H(2)O)]·5H(2)O (1), [Co(2)(en)(3)][Co(en)(2)](2)[Co(en)(2)(H(2)O)][V(16)Ge(4)O(44)(OH)(2)(H(2)O)]·10.5H(2)O (2), (pdn = 1,2-propanediamine, en = ethylenediamine) have been synthesized under hydrothermal conditions via changing the organic amine. X-ray crystal structure analyses reveal that both frameworks are built of [V(16)Ge(4)O(44)(OH)(2)(H(2)O)](10-) anions and different Co-amine cations. They represent the first example of incorporating elemental Co into the extended vanadogermanate frameworks. Compound 1 shows a 3D framework with NaCl topology based on {V(16)Ge(4)} clusters as nodes, while compound 2 exhibits a 3D (4,6)-connected network with a Schl?fli symbol of (4(6)·6(7)·8(2))(2)(4(2)·6(4)), which is found for the first time in polyoxovanadate chemistry. The diverse types of metal-organoamine subunits play critical roles in the formation on the final structures. Furthermore, variable temperature susceptibility measurements on compounds 1 and 2 demonstrate the presence of anticipated rare ferrimagnetic behavior.     

Syntheses and crystal structures of two new bismuth hydroxyl borates containing [Bi2O2]2+ layers: Bi2O2[B3O5(OH)] and Bi2O2[BO2(OH)

Two new bismuth hydroxyl borates, Bi(2)O(2)[B(3)O(5)(OH)] (I) and Bi(2)O(2)[BO(2)(OH)] (II), have been synthesized under hydrothermal conditions. Their structures were determined by single-crystal and powder X-ray diffraction data, respectively. Compound I crystallizes in the orthorhombic space group Pbca with the lattice constants of a = 6.0268(3) ?, b = 11.3635(6) ?, and c = 19.348(1) ?. Compound II crystallizes in the monoclinic space group Cm with the lattice constants of a = 5.4676(6) ?, b = 14.6643(5) ?, c = 3.9058(1) ?, and β = 135.587(6)°. The borate fundamental building block (FBB) in I is a three-ring unit [B(3)O(6)(OH)](4-), which connects one by one via sharing corners, forming an infinite zigzag chain along the a direction. The borate chains are further linked by hydrogen bonds, showing as a borate layer within the ab plane. The FBB in II is an isolated [BO(2)(OH)](2-) triangle, which links to two neighboring FBBs by strong hydrogen bonds, resulting in a borate chain along the a direction. Both compounds contain [Bi(2)O(2)](2+) layers, and the [Bi(2)O(2)](2+) layers combine with the corresponding borate layers alternatively, forming the whole structures. These two new bismuth borates are the first ones containing [Bi(2)O(2)](2+) layers in borates. The appearance of Bi(2)O(2)[BO(2)(OH)] (II) completes the series of compounds Bi(2)O(2)[BO(2)(OH)], Bi(2)O(2)CO(3), and Bi(2)O(2)[NO(3)(OH)] and the formation of Bi(2)O(2)[B(3)O(5)(OH)] provides another example in demonstrating the polymerization tendency of borate groups.     

Hydrothermal synthesis and crystal structures of two novel acentric mixed alkaline earth metal berylloborates Sr3Be2B5O12(OH) and Ba3Be2B5O12(OH)

The synthesis and structure of the isostructural acentric compounds Sr(3)Be(2)B(5)O(12)(OH) (1) and Ba(3)Be(2)B(5)O(12)(OH) (2) are reported for the first time. These compounds crystallize in the space group R3m, and the unit cell parameters are a = 10.277(15) ? and c = 8.484(17) ? for 1 and a = 10.5615(15) ? and c = 8.8574(18) ? for 2. The structures consist of a network of [Be(2)B(4)O(12)(OH)] units interwoven with a network consisting of MO(9) polyhedra (M = Sr, Ba) and BO(3) triangles and exemplify how acentric building blocks such as [BO(3)](3-), [BO(4)](5-), and [BeO(4)](6-) can be especially suitable to build noncentrosymmetric long-range structures. Both networks are centered on the 3-fold rotation axis and present themselves in alternating fashion along [001]. Acentricity is imparted by the alignment of the polarities of BO(3) and BeO(4) environments. Infrared spectroscopy has been used to confirm the local geometries of B and Be, as well as the presence of hydroxide in the crystal structure. Another interesting feature of these compounds is the presence of disorder involving Be and B at the tetrahedral Be site. The degree of the disorder has been confirmed by observing a noticeable shortening of average Be-O bond distances.     

Hydrothermal synthesis and crystal structure of two new hydrated alkaline earth metal borates Sr3B6O11(OH)2 and Ba3B6O11(OH)2

Two new hydrated borates Sr(3)B(6)O(11)(OH)(2) (1) and Ba(3)B(6)O(11)(OH)(2) (2) were hydrothermally synthesized. Their structures were determined by single-crystal X-ray diffraction and further characterized by IR, powder XRD, and DSC/TGA. Compound 1 crystallizes in the triclinic space group P-1 with unit cell parameters of a = 6.6275(13) ?, b = 6.6706(13) ?, c = 11.393(2) ?, α = 91.06(3)°, β = 94.50(3)°, and γ = 93.12(3)°, while compound 2 crystallizes in the noncentrosymmetric monoclinic space group Pc with a = 6.958(14) ?, b = 7.024(14) ?, c = 11.346(2) ?, and β = 90.10(3)°. In spite of the differences in symmetry and packing of the borate chains, both structures consist of the same fundamental building block (FBB) of a [B(6)O(11)(OH)(2)](-6) unit and three unique alkaline earth metal atoms.     

UV nonlinear optical crystal Ba2[B6O9(OH)4] featuring unique chiral layers with a new B18O42 circle based on BO3 and BO4 units

A new noncentrosymmetric polyborate, Ba(2)[B(6)O(9)(OH)(4)], has been synthesized under a hydrothermal condition. The polyborate contains chiral layers constructed by two kinds of helical chains and also form new B(18)O(42) circles based on B(3)O(8) units [(3: Δ+2T)]. One kind of Ba atom locates in the cavity surrounded by the B(11)O(11) ring within the anion layer, and the other kind of Ba atom inserts between two adjacent layers. UV-vis diffuse reflectance spectroscopy demonstrates that the compound has a cutoff edge below 190 nm and has a large second-harmonic generation (SHG) effect, which is approximately 3 times that of KH(2)PO(4) (KDP) and is type-I phase matchable.     

CsB3GeO7 and K2B2Ge3O10: explorations of new second-order nonlinear optical materials in the borogermanate systems

Two novel alkali(I) borogermanates with noncentrosymmetric structures, namely, CsB 3GeO 7 and K 2B 2Ge 3O 10, have been synthesized by high-temperature solid-state reactions in a platinum crucible. The structure of CsB 3GeO 7 features a novel three-dimensional (3D) framework composed of cyclic B 3O 7 (5-) groups that are interconnected by Ge(IV) cations, whereas the structure of K 2B 2Ge 3O 10 is a new 3D network based on cap-shaped [Ge 3B 2O 14] (10-) clusters that are interconnected via Ge-O-B bridges. CsB 3GeO 7 exhibits a second-harmonic generation (SHG) response that is about 1.5 times that of KDP (KH 2PO 4), whereas the SHG signal of K 2B 2Ge 3O 10 is very weak. Both compounds are insulators and transparent in the range of 300-5000 nm. The electronic structure calculations for both compounds also have been performed.     

Synthesis, crystal structure, and solution stability of Keggin-type heteropolytungstates (NH4)6NiII0.5[alpha-FeIIIO4W11O30NiIIO5(OH2)].nH2O, (NH4)7Zn0.5[alpha-ZnO4W11O30ZnO5(OH2)].nH2O, and (NH4)7NiII0.5[alpha-ZnO4W11O30NiIIO5(OH2)].nH2O (n approximately 18)

Reaction of acidified (pH approximately 7) sodium tungstate solutions with transition metal cations (Fe(3+), Ni(2+), Zn(2+), Co(2+)) leads to the formation of transition-metal-disubstituted Keggin-type heteropolytungstates with 3d-metal ions distributed over three different positions. A detailed investigation of the synthesis conditions confirmed that the complexes could equally be obtained using aqueous solutions of either Na(2)WO(4).2H(2)O (sodium monotungstate) at pH approximately 7, Na(6)[W(7)O(24)]. approximately 14H(2)O (sodium paratungstate A), or Na(10)[H(2)W(12)O(42)].27H(2)O (sodium paratungstate B) as starting materials. Three complexes, (NH(4))(6)Ni(II)(0.5)[alpha-Fe(III)O(4)W(11)O(30)Ni(II)O(5)(OH(2))].18H(2)O, (NH(4))(7)Zn(0.5)[alpha-ZnO(4)W(11)O(30) ZnO(5)(OH(2))].18H(2)O, and (NH(4))(7)Ni(II)(0.5)[alpha-ZnO(4)W(11)O(30)Ni(II)O(5)(OH(2))].18H(2)O were isolated in crystalline form. X-ray single-crystal structure analysis revealed that the solid-state structures of the three compounds consist of four main structural fragments, namely [MO(4)W(11)O(30)M'O(5)(OH(2))](n-) (Keggin-type, alpha-isomer) heteropolytungstates, hexaquo metal cations, [M'(OH(2))(6)](2+), ammonium-water cluster ions, [(NH(4)(+))(8)(OH(2))(12)], and additional ammonium cations and water molecules. The 3d metals occupy the central (tetrahedral, M) and the peripheral (octahedral, M') positions of the Keggin anion, as well as cationic sites (M') outside of the polyoxotungstate framework. UV-vis spectroscopy, solution ((1)H, (183)W) and solid-state ((1)H) NMR, and also chemical analysis data provided evidence that the 3d-metal-disubstituted Keggin anions do not exist in solution but are being formed only during the crystallization process. Investigations in the solid state and in solution were completed by ESR, IR, and Raman measurements.     

A novel polyoxovanadium borate incorporating an organic amine ligand: synthesis and structure of [V12B16O50(OH)7(en)]7-

A novel 1D chain organic-inorganic hybrid polyoxovanadium borate Na[V(12)B(16)O(50)(OH)(7)(en)](2)(enH(2))(6)(enH)(2)(OH)(H(2)O)(19) (1, en = ethylenediamine), based on a [V(12)B(16)O(50)(OH)(7)(en)](7-) cluster unit, has been hydrothermally synthesized and characterized. Interestingly, organic amine is incorporating into the V(12)B(16) clusters.     

K3[Tb(x)Eu(1-x)Ge3O8(OH)2] (x = 1, 0.88, 0.67, 0): 2D-layered lanthanide germanates with tunable photoluminescent properties

A family of novel 2D-layered lanthanide germanates K(3)[Tb(x)Eu(1-x)Ge(3)O(8)(OH)(2)] (x = 1, 0.88, 0.67, 0; denoted as TbGeO-JU-87, Tb(0.88)Eu(0.12)GeO-JU-87, Tb(0.67)Eu(0.33)GeO-JU-87, and EuGeO-JU-87) were synthesized under mild hydrothermal conditions in a concentrated gel system. They are isostructural, as confirmed by the powder X-ray diffraction analysis. The single-crystal X-ray diffraction analysis of EuGeO-JU-87 reveals that it is a 2D-layered [EuGe(3)O(8)(OH)(2)](n)(3n-) anionic framework, which is built up from GeO(4)H/GeO(4) tetrahedra and EuO(6) octahedra by sharing vertex O atoms. Charge neutrality is achieved by K(+) ions located in the free void space. Interestingly, photoluminescence studies show that Tb(0.88)Eu(0.12)GeO-JU-87 and Tb(0.67)Eu(0.33)GeO-JU-87 exhibit a high Tb(3+)-to-Eu(3+) energy-transfer efficiency and the Tb(x)Eu(1-x)GeO-JU-87 system displays tunable photoluminescent properties.     

Synthesis and structure of QD-6: a novel aluminoborate constructed from unprecedented [B@Al6O24] and polyborate clusters

A novel aluminoborate (NH(4))(6)[C(5)NH(12)](6)[Al(12)B(65)O(105)(OH)(33)]·(H(2)O)(15) (QD-6), has been synthesized under mild hydrothermal conditions and characterized by IR, elemental analysis, TGA, powder and single-crystal X-ray diffractions. This compound crystallizes in the rhombohedral space group R3 (No. 148) with the lattice constants a = 23.7421(2) ?, c = 24.7699(3) ?, V = 12091.9(2) ?(3), and Z = 3. QD-6 consists of two unprecedented aluminoborate clusters, [Al(6)B(34)O(54)(OH)(18)](6-) and [Al(6)B(31)O(51)(OH)(15)](6-), which are built from the same hexagon-like [B@Al(6)O(24)] clusters and [B(11)O(17)(OH)(6)] or [B(10)O(16)(OH)(5)] polyborates.     

NH4]2Mn3(H2O)4[Mo(CN)7]2.4H2O: tuning dimensionality and ferrimagnetic ordering temperature by cation substitution

[NH(4)](2)Mn(3)(H(2)O)(4)[Mo(CN)(7)](2).4H(2)O (1) has been synthesized by slow diffusion of aqueous solutions containing K(4)[Mo(CN)(7)].2H(2)O, [Mn(H(2)O)(6)](NO(3))(2), and (NH(4))NO(3). Compound 1 crystallizes in the monoclinic C2/c space group. The basic motif of the three-dimensional structure consists of a Mo1-Mn1 gridlike sheet parallel to the bc plane. Two of these sheets are connected through CN-Mn2-NC linkages to form a bilayer reminiscent of the K(2)Mn(3)(H(2)O)(6)[Mo(CN)(7)](2).6H(2)O (2) two-dimensional structure. In 1, [NH(4)](+) cations allow these bilayers to be connected through direct Mo1-CN-Mn1 bridges to form a three-dimensional network, whereas in 2, they are isolated by (H(2)O)K(+) cations. As shown by the magnetic measurements, this increase of dimensionality by counterion substitution induces an enhancement of the ferrimagnetic critical temperature from 39 K in 2 to 53 K in 1.     

Expanding the remarkable structural diversity of uranyl tellurites: hydrothermal preparation and structures of K[UO(2)Te(2)O(5)(OH)], Tl(3)[(UO(2))(2)[Te(2)O(5)(OH)](Te(2)O(6))].2H(2)O,beta-Tl(2)[UO(2)(TeO(3))(2)], and Sr(3)[UO(2)(TeO(3))(2)](TeO(3))(2)

The reactions of UO(2)(C(2)H(3)O(2))(2).2H(2)O with K(2)TeO(3).H(2)O, Na(2)TeO(3) and TlCl, or Na(2)TeO(3) and Sr(OH)(2).8H(2)O under mild hydrothermal conditions yield K[UO(2)Te(2)O(5)(OH)] (1), Tl(3)[(UO(2))(2)[Te(2)O(5)(OH)](Te(2)O(6))].2H(2)O (2) and beta-Tl(2)[UO(2)(TeO(3))(2)] (3), or Sr(3)[UO(2)(TeO(3))(2)](TeO(3))(2) (4), respectively. The structure of 1 consists of tetragonal bipyramidal U(VI) centers that are bound by terminal oxo groups and tellurite anions. These UO(6) units span between one-dimensional chains of corner-sharing, square pyramidal TeO(4) polyhedra to create two-dimensional layers. Alternating corner-shared oxygen atoms in the tellurium oxide chains are protonated to create short/long bonding patterns. The one-dimensional chains of corner-sharing TeO(4) units found in 1 are also present in 2. However, in 2 there are two distinct chains present, one where alternating corner-shared oxygen atoms are protonated, and one where the chains are unprotonated. The uranyl moieties in 2 are bound by five oxygen atoms from the tellurite chains to create seven-coordinate pentagonal bipyramidal U(VI). The structures of 3 and 4 both contain one-dimensional [UO(2)(TeO(3))(2)](2-) chains constructed from tetragonal bipyramidal U(VI) centers that are bridged by tellurite anions. The chains differ between 3 and 4 in that all of the pyramidal tellurite anions in 3 have the same orientation, whereas the tellurite anions in 4 have opposite orientations on each side of the chain. In 4, there are also additional isolated TeO(3)(2-) anions present. Crystallographic data: 1, orthorhombic, space group Cmcm, a = 7.9993(5) A, b = 8.7416(6) A, c = 11.4413(8) A, Z = 4; 2, orthorhombic, space group Pbam, a = 10.0623(8) A, b = 23.024(2) A, c = 7.9389(6) A, Z = 4; 3, monoclinic, space group P2(1)/n, a = 5.4766(4) A, b = 8.2348(6) A, c = 20.849(3) A, beta = 92.329(1) degrees, Z = 4; 4, monoclinic, space group C2/c, a = 20.546(1) A, b = 5.6571(3) A, c = 13.0979(8) A, beta = 94.416(1) degrees, Z = 4.     

Synthesis, structure, and characterization of novel two- and three-dimensional vanadates: Ba2.5(VO2)3(SeO3)4.H2O and La(VO2)3(TeO6).3H2O

Two new vanadates, Ba(2.5)(VO2)3(SeO3)4.H2O and La(VO2)3(TeO6).3H2O, have been synthesized by hydrothermal methods using BaCO3, Ba(OH)2.H2O, La(NO3)3.6H2O, V2O5, TeO2, and H2SeO3 as reagents. The structures were determined by single-crystal X-ray diffraction. Ba(2.5)(VO2)3(SeO3)4.H2O exhibits a two-dimensional layered structure consisting of VO(5) square pyramids and SeO3 polyhedra, whereas La(VO2)3(TeO6).3H2O has a three-dimensional framework structure composed of VO(4) tetrahedra and TeO6 octahedra. Infrared and Raman spectroscopy, UV-vis diffuse reflectance spectroscopy, and thermogravimetric analysis are also presented. Crystal data: Ba(2.5)(VO2)3(SeO3)4.H2O, trigonal, space group P (No. 147) with a = b = 12.8279(15) A, c = 7.2631(9) A, V = 1035.1(2) A(3), and Z = 2; La(VO2)3(TeO6).3H2O, trigonal, space group R3c (No. 161) with a = b = 9.4577(16) A, c = 23.455(7) A, V = 1816.9(7) A3, and Z = 6.     

Syntheses, structures, and ion-exchange properties of the three-dimensional framework uranyl gallium phosphates, Cs4[(UO2)2(GaOH)2(PO4)4].H2O and Cs[UO2Ga(PO4)2

The reaction of UO(2)(NO(3))(2).6H(2)O with Cs(2)CO(3) or CsCl, H(3)PO(4), and Ga(2)O(3) under mild hydrothermal conditions results in the formation of Cs(4)[(UO(2))(2)(GaOH)(2)(PO(4))(4)].H(2)O (UGaP-1) or Cs[UO(2)Ga(PO(4))(2)] (UGaP-2). The structure of UGaP-1 was solved from a twinned crystal revealing a three-dimensional framework structure consisting of one-dimensional (1)(infinity)[Ga(OH)(PO(4))(2)](4-) chains composed of corner-sharing GaO(6) octahedra and bridging PO(4) tetrahedra that extend along the c axis. The phosphate anions bind the UO(2)(2+) cations to form UO(7) pentagonal bipyramids. The UO(7) moieties edge-share to create dimers that link the gallium phosphate substructure into a three-dimensional (3)(infinity)[(UO(2))(2)(GaOH)(2)(PO(4))(4)](4-) anionic lattice that has intersecting channels running down the b and c axes. Cs(+) cations and water molecules occupy these channels. The structure of UGaP-2 is also three-dimensional and contains one-dimensional (1)(infinity)[Ga(PO(4))(2)](3-) gallium phosphate chains that extend down the a axis. These chains are formed from fused eight-membered rings of corner-sharing GaO(4) and PO(4) tetrahedra. The chains are in turn linked together into a three-dimensional (3)(infinity)[UO(2)Ga(PO(4))(2)](1-) framework by edge-sharing UO(7) dimers as occurs in UGaP-1. There are channels that run down the a and b axes through the framework. These channels contain the Cs(+) cations. Ion-exchange studies indicate that the Cs(+) cations in UGaP-1 and UGaP-2 can be exchanged for Ca(2+) and Ba(2+). Crystallographic data: UGaP-1, monoclinic, space group P2(1)/c, a = 18.872(1), b = 9.5105(7), c = 14.007(1) A, beta = 109.65(3)(o) , Z = 4 (T = 295 K); UGaP-2, triclinic, space group P, a = 7.7765(6), b = 8.5043(7), c = 8.9115(7) A, alpha = 66.642(1)(o), beta = 70.563(1)(o), gamma = 84.003(2)(o), Z = 2 (T = 193 K).     

Synthesis and structure of the pentacopper(II) substituted tungstosilicate [Cu5(OH)4(H2O)2(A-alpha-SiW9O33)2]10-

The dimeric, pentacopper(II) substituted tungstosilicate [Cu(5)(OH)(4)(H(2)O)(2)(A-alpha-SiW(9)O(33))(2)](10-) (1) has been synthesized in good yield using a one-pot procedure by reaction of Cu(2+) ions with the trilacunary precursor salt K(10)[A-alpha-SiW(9)O(34)]. The title polyanion represents the first polyoxotungstate substituted by 5 copper centers and the central copper-hydroxo-aqua fragment is completely unprecedented. In the course of the reaction, two [A-alpha-SiW(9)O(34)](10-) Keggin half-units have fused in an asymmetrical fashion resulting in the lacunary polyoxotungstate [Si(2)W(18)O(66)](16-). The vacancy in this species is stabilized by a magnetic cluster of five octahedrally coordinated Cu(2+) ions resulting in polyanion 1 with C(2v) symmetry.     

Synthesis of an open-framework copper-germanium phosphate [Cu(H2O)2(OH)]2Ge(PO4)2

A novel open-framework material [Cu(H(2)O)(2)(OH)](2)Ge(PO(4))(2), which was synthesized by a hydrothermal method, is built of GeO(6), CuO(6) octahedra and PO(4) tetrahedra, and possesses a network of interconnecting six- and eight-membered ring channels.     

Excision of uranium oxide chains and ribbons in the novel one-dimensional uranyl iodates K(2)[(UO(2))3(IO(3))(4)O(2)] and Ba[(UO(2)2(IO(3))(2)O(2)](H(2)O)

The alkali metal and alkaline-earth metal uranyl iodates K(2)[(UO(2))(3)(IO(3))(4)O(2)] and Ba[(UO(2))(2)(IO(3))(2)O(2)](H(2)O) have been prepared from the hydrothermal reactions of KCl or BaCl(2) with UO(3) and I(2)O(5) at 425 and 180 degrees C, respectively. While K(2)[(UO(2))(3)(IO(3))(4)O(2)] can be synthesized under both mild and supercritical conditions, the yield increases from <5% to 73% as the temperature is raised from 180 to 425 degrees C. Ba[(UO(2))(2)(IO(3))(2)O(2)](H(2)O), however, has only been isolated from reactions performed in the mild temperature regime. Thermal measurements (DSC) indicate that K(2)[(UO(2))(3)(IO(3))(4)O(2)] is more stable than Ba[(UO(2))(2)(IO(3))(2)O(2)](H(2)O) and that both compounds decompose through thermal disproportionation at 579 and 575 degrees C, respectively. The difference in the thermal behavior of these compounds provides a basis for the divergence of their preparation temperatures. The structure of K(2)[(UO(2))(3)(IO(3))(4)O(2)] is composed of [(UO(2))(3)(IO(3))(4)O(2)](2)(-) chains built from the edge-sharing UO(7) pentagonal bipyramids and UO(6) octahedra. Ba[(UO(2))(2)(IO(3))(2)O(2)](H(2)O) consists of one-dimensional [(UO(2))(2)(IO(3))(2)O(2)](2)(-) ribbons formed from the edge sharing of distorted UO(7) pentagonal bipyramids. In both compounds the iodate groups occur in both bridging and monodentate binding modes and further serve to terminate the edges of the uranium oxide chains. The K(+) or Ba(2+) cations separate the chains or ribbons in these compounds forming bonds with terminal oxygen atoms from the iodate ligands. Crystallographic data: K(2)[(UO(2))(3)(IO(3))(4)O(2)], triclinic, space group P_1, a = 7.0372(5) A, b = 7.7727(5) A, c = 8.9851(6) A, alpha = 93.386(1) degrees, beta = 105.668(1) degrees, gamma = 91.339(1) degrees, Z = 1; Ba[(UO(2))(2)(IO(3))(2)O(2)](H(2)O), monoclinic, space group P2(1)/c, a = 8.062(4) A, b = 6.940(3) A, c = 21.67(1), beta= 98.05(1) degrees, Z = 4.     

Investigation of the crystal structure of a basic bismuth(III) nitrate with the composition [Bi6O4(OH)4](0.54(1))[Bi6O5(OH)3](0.46(1))(NO3)(5.54(1))

A basic bismuth(III) nitrate with the composition [Bi(6)O(4)(OH)(4)](0.5)[Bi(6)O(5)(OH)(3)](0.5)(NO(3))(5.5) formed in a slow crystal growth mode has an ordered crystal structure with the monoclinic space group P2(1) and lattice parameters a = 15.850(3), b = 14.986(3), c = 18.230(4) ?, β = 107.329(17)° and volume V = 4133.6 ?(3) (Henry et al. 2003). In a very fast crystal growth mode the complex ions disorder in another P2(1) cell with slightly different lattice parameters a = 15.8404(1), b = 15.1982(1), c = 18.3122(1) ?, β = 106.829(1)° and V = 4219.8 ?(3). This cell can be related to two smaller cells: a monoclinic C2/m cell with a = 13.7161(1), b = 15.1943(1), c = 10.2399(1) ?, β = 98.586(1)° and V = 2110.1 ?(3) and a trigonal R3 cell with a = 15.18650(6), c = 15.8416(1) ? (hexagonal setting) and V = 3164.1 ?(3). These smaller cells correspond to average structures and hence the X-ray data do not account for the difference in the structures of the two different complex ions. However, when analysing neutron powder diffraction data, it is possible to distinguish between the two complex ions using a trigonal R3 cell with a = 15.1865(1) and c = 15.8416(1) ? (hexagonal setting). In a Rietveld type structure model refinement with a total of 28 atom sites (4 Bi, 3 N, 15 O and 6 H), the composition of this sample is determined to be [Bi(6)O(4)(OH)(4)](0.54(1))[Bi(6)O(5)(OH)(3)](0.46(1))(NO(3))(5.54(1)).