Synthesis and Structures of the Capped and Sandwiched Cobalt Heptamolybdate Polyoxometalate (NH₄)₆{[Co(H₂O)₅][Mo₇O₂₄][Co(H₂O)₂][Mo₇O₂₄][Co(H₂O)₅]} · 6 H₂O and Its Extended Structure (NH₄)₆{[Co(H₂O)₂]₃[Mo₇O₂₄]₂}

Two polyoxometalate-based compounds containing the heptamolybdate anion and cobalt(II) have been synthesized, structurally characterized via single-crystal X-ray diffraction and spectroscopically analyzed with solid-state UV–Vis–NIR. The first crystal structure presented is a capped- and sandwich-style polyoxometalate (NH4)6{[Co(H2O)5][Mo7O24] [Co(H2O)2][Mo7O24][Co(H2O)5]} · 6 H2O (Co3Mo14-POM). This orange product crystallizes in the P-1 space group and has an interesting structure for polyoxometalates (POMs). Here, the cobalt(II) groups are functioning both as a bridge between two heptamolybdate units and also capping units at the top and the bottom of the polyoxometalate. The second structure, another product within the same reaction, is constructed on a similar bonding motif but now forms an extended structure: (NH4)6{[Co(H2O)2]3[Mo7O24]2} (Co3Mo14-ES). This compound also crystallizes in the space group P-1 but is easily separated due to its much darker red-violet color. These structures present themselves as a noteworthy compounds within POM-based crystal structures. Herein, the syntheses, crystal structures and characterization of these compounds are presented

A new low temperature route to uranyl borates with structural variations

AbstractThree new uranyl borates, K(UO</jats:p

A New Family of Lanthanide Borate Halides with Unusual Coordination and a New Neodymium-Containing Cationic Framework

The reactions of Ln2O3/CeO2/Pr6O11 (Ln = La–Nd, Sm), molten boric acid, and concentrated HBr or HI result in the formation of La[B7O10(OH)3(H2O)Br], Ln[B6O9(OH)2(H2O)2Br]·0.5H2O (Ln = Ce, Pr), Nd2[B12O17.5(OH)5(H2O)4Br1.5]Br0.5·H2O (NdBOBr), Sm4[B18O25(OH)13Br3], and Ln[B7O11(OH)(H2O)3I] (Ln = La–Nd, Sm). The lanthanide(III) centers in these compounds are found with 9-coordinate hula hoop or 10-coordinate capped triangular cupola geometries, where there are six approximately coplanar oxygen donors provided by the polyborate sheet. The sheets are formed into three-dimensional frameworks via BO3 triangles that are roughly perpendicular to the layers. Additionally, a new cationic framework, NdBOBr, has been isolated. NdBOBr is unusual in that not only is it a cationic framework, but it is also the first trivalent f-element borate to have terminal halides bound exclusively to the base site of the hula hoop. The Ln[B7O11(OH)(H2O)3I] (Ln = La–Nd, Sm) structures require two corner-shared BO3 units in order to tether the layers together because of the large size of the capping iodine atom

Synthesis of Divalent Europium Borate via in Situ Reductive Techniques

A new divalent europium borate, Eu[B8O11(OH)4], was synthesized by two different in situ reductive methodologies starting with a trivalent europium starting material in a molten boric acid flux. The two in situ reductive techniques employed were the use of HI as a source of H2 gas and the use of a Zn amalgam as a reductive, reactive surface. While both of these are known reductive techniques, the title compound was synthesized in both air and water which demonstrates that strict anaerobic conditions need not be employed in conjunction with these reductive methodologies. Herein, we report on the structure, spectroscopy, and synthetic methodologies relevant to Eu[B8O11(OH)4]. We also report on a europium doping study of the isostructural compound Sr[B8O11(OH)4] where the amount of doped Eu2+ ranges from 2.5 to 11%

[Ag₂M(Te₂O₅)₂]SO₄ (M = Ce^IV or Th^IV): A New Purely Inorganic d/f-Heterometallic Cationic Material

Two new isotypic d/f-heterometallic purely inorganic cationic materials, [Ag₂M­(Te₂O₅)₂]­SO₄ (M = Ce^IV or Th^IV), were synthesized using the metal oxides (MO₂ and TeO₂), silver nitrate, and sulfuric acid under mild hydrothermal conditions. The prepared materials were characterized via single-crystal X-ray diffraction, which revealed that the materials possess a 3D framework of corner-sharing Te₂O₅^2– units. The tellurite framework creates four unique pores, three of which are occupied by the M^IV and Ag^I metal centers. The tellurite network, metal coordination, and total charge yield a cationic framework, which is charge-balanced by electrostatically bound sulfate anions residing in the largest of the four framework pores. These materials also possess Ag^I in a ligand-imposed linear geometry

Ionothermal and Hydrothermal Flux Syntheses of Five New Uranyl Phosphonates

Four new uranyl phosphonate compounds have been synthesized via ionothermal flux in the ionic liquids 1-butyl-3-methylimidazolium chloride ([Bmim]­[Cl]) and 1-ethyl-3-methylimidazolium bromide ([Emim]­[Br]). [C₈H₁₅N₂]­[UO₂(C₆H₅PO₃H)­(C₆H₅PO₃)] (<b>[Bmim]­[UPhPO]</b>), [C₈H₁₅N₂]₂[(UO₂)₄(C₆H₅PO₃)₃Cl₄] (<b>[Bmim]­[UPhPOCl]</b>), [C₈H₁₅N₂]­[UO₂(HO₃P­(CH₂)₃PO₃)] (<b>α-[Bmim]­[UC</b>_<b>3</b><b>DPO]</b>), and [C₆H₁₁N₂]₂[(UO₂)₂(<i>p</i>-C₆H₄(PO₃H)₂)₃]·2H₂O (<b>[Emim]­[UPhDPO]</b>) form one-dimensional chains, two-dimensional sheets, or three-dimensional frameworks. For comparison, analogous reactions were carried out hydrothermally, which lead to one new framework structure, [C₈H₁₅N₂]₂[(UO₂)₅(HO₃P­(CH₂)₃PO₃)₄] (<b>β-[Bmim]­[UC</b>_<b>3</b><b>DPO]</b>), and one previously characterized tubular uranyl phosphonate. It was found that the structure is equally dictated by the choice of flux method, the choice of ligand, and the choice of ionic liquid