On the Crystal Structure of a Previously Unknown Anhydrous Zinc Hydroxide Sulfate

Anhydrous zinc hydroxide sulfates are promising precursors for the preparation of pigments and ZnO nanomaterials. The crystal structure of one such compound 5[Zn(OH)₂] · 2[ZnSO₄] was determined from high resolution laboratory X‐ray powder diffraction data by use of a combination of charge flipping, 18 simulated annealing, 26 and difference Fourier analysis. The material crystallizes in the space group P$\bar{1}$ with the lattice parameters of a = 5.4559(2) Å, b = 8.0528(3) Å, c = 8.9275(3) Å, α = 112.697(2)°, β = 85.219(3)°, γ = 95.441(3)°, and a volume of V = 359.76(2) ų. The basic crystal structure consists of brucite type Zn(OH)₂ layers where every sixth octahedral site is vacant. Tetrahedrally coordinated zinc ions are located above and below these vacancies and consecutive layers are bridged by sulfate molecules. The composition of this layered structure can be written as [Zn₅^VI□(OH)₄ · Zn₂^IV(OH)₆ · (SO₄)₂]. Its thermal decomposition was studied by X‐ray powder diffraction and thermal analysis.     

Hydrothermal Synthesis of a New Vanadium Tellurate(VI) with a Novel Chain Structure: (NH4)4{(VO2)2[Te2O8(OH)2]}·2H2O

A new ammonium vanadium tellurate, (NH₄)₄{(VO₂)₂[Te₂O₈(OH)₂]}·2H₂O ( 1 ) was hydrothermally synthesized and characterized by elemental analyses, IR spectrum, TG analysis, and single crystal X–ray diffraction. Compound 1 crystallizes in the monoclinic system, space group P2₁/n, a = 7.3843(15) Å, b = 17.111(3) Å, c = 7.3916(15) Å, β = 118.88(3)°, V = 817.9(3) ų, Z = 2, R1 (I>2σ(I)) = 0.0235, wR2 (all data) = 0.0462. The structure of 1 consists of infinite anionic chains, {(VO₂)₂[Te₂O₈(OH)₂]}^4? which contain octahedral VO₆ and TeO₅OH units. Each octahedral VO₆ and TeO₅OH unit is connected by sharing an edge to form V₂O₁₀ and Te₂O₈(OH)₂ binuclear units. The V₂O₁₀ and Te₂O₈(OH)₂ binuclear units are alternatively connected to one another, creating complete infinite {(VO₂)₂[Te₂O₈(OH)₂]}^4? chains along the c direction. The anionic chains are separated by ammonium cations and water molecules that link the chains through a network of hydrogen bonds. In addition, the structure contains an extended network of O–H·····O hydrogen bonds between the chains.     

M[B(CN)4]2: Zwei neue Tetracyanoborate mit zweiwertigen Kationen (M = Zn,Cu)

M[B(CN)₄]₂: Two new Tetracyanoborate Compounds with divalent Cations (M = Zn, Cu) The reaction of ZnO or CuO with [H₃O][B(CN)₄] in aqueous solution yielded single crystals of Zn[B(CN)₄]₂ and Cu[B(CN)₄]₂, respectively. The compounds were characterized by single‐crystal X‐ray diffraction. Zn[B(CN)₄]₂ ( (no. 164), a = b = 7.5092(9) Å, c = 6.0159(6) Å, Z = 1) crystallizes isotypic with Hg[B(CN)₄]₂. The structure of Cu[B(CN)₄]₂ (C2/m (no. 12), a = 13.185(3) Å, b = 7.2919(9) Å, c = 6.029(1) Å, β = 93.02(2)°, Z = 2) can be considered as a super‐structure, resulting from Jahn‐Teller distortion of the Cu²⁺ ions. Magnetic measurements were performed for the copper compound. Vibrational spectra and thermal stabilities were compared with the known mercury(II) tetracyanoborate.     

Hydrothermal Synthesis and X‐ray Crystal Structure of Four Inorganic‐Organic Hybrid Compounds in Vanadium /Copper Iodate Family

Four inorganic‐organic hybrid compounds with the formulae (1,10‐phen)(VO₂)(IO₃) ( 1 ), (2,2′‐bipy)(VO₂)(IO₃) ( 2 ), [Cu₃(2,2′‐bipy)₃Cl₃(IO₃)₂]·I_1.5 ( 3 ), and [Cu(2,2′‐bipy)(H₂O)(IO₃)₂]· (H₂O)₂ ( 4 ) are hydrothermally synthesized at 120 °C for 6 d and characterized by single‐crystal X‐ray diffraction. The use of two different bidentate organodiamine ligands 1,10‐phen and 2,2′‐bipy in the V/I/O system gives rise to compounds 1 and 2 , which crystallize in a monoclinic system with the space group C2/c, a = 17.8131(6) Å, b = 15.0470(7) Å, c = 12.9902(4) Å, β = 133.095(2)°, V = 2542.49(17) ų for 1 and space group P2₁/c, a = 13.3095(5) Å, b = 15.0993(8) Å, c = 13.0454(4) Å, β = 116.971(2)°, V = 2335.88(17) ų for 2 . The use of the bidentate organodiamine ligand 2,2′‐bipy in the Cu/I/O system gives rise to the variety in the structure of products 3 and 4 , which crystallize in a triclinic system with the same space group . a = 8.5143(2) Å, b = 10.4908(3) Å, c = 22.8420(6) Å, α = 93.769(10)°, β = 91.723(10)°, γ = 112.111(10)°, V = 1882.83(9) ų for 3 and a = 6.731(6) Å, b = 10.110(4) Å, c = 12.899(6) Å, α = 106.00(5)°, β = 95.45(4)°, γ = 107.69(6)°, V = 788.4(9) ų for 4 . The solid‐state structures of the compounds 1 and 2 have chains with repeat units of alternative corner sharing of [VO₄N₂] octahedra and [IO₃] pyramids. Compound 3 is a chain containing [IO₃] pyramids and [VO₄N] square pyramids and compound 4 consists of Cu(2,2′‐bipy)²⁺ linked by one water molecule and two [IO₃] pyramids. The thermal stabilities of the compounds are investigated.     

Synthese und Kristallstruktur von Na2Zn(OH)4

Synthesis and Crystal Structure of Na₂Zn(OH)₄ Crystallization from saturated sodium hydroxozincate solutions yields colourless platelets of crystals of Na₂Zn(OH)₄. The X‐ray structure determination on these crystals was successful including all hydrogen positions. P2₁/n, Z = 4, a = 7.959(3) Å, b = 6.534(1) Å, c = 8.501(3) Å, β = 93.97(3)°, N(F²_o ° 2σ F²_o) = 1668, N(Var.) = 81, R₁/wR₂ = 0.043/0.107. Na₂Zn(OH)₄ crystallizes in a layered structure. Alternate layers contain Na⁺ in octahedral and Zn²⁺ in tetrahedral coordination by OH^–.     

The Cocrystallization of the Cubic [Ta6Br12(H2O)6][CuBr2X2]·10H2O and Triclinic [Ta6Br12(H2O)6]X2·trans‐[Ta6Br12(OH)4(H2O)2]·18H2O (X = Cl,Br, NO3) Phases with the Coexistence of [Ta6Br12]2+ and [Ta6Br12]4+ in the Latter

Cubic [Ta₆Br₁₂(H₂O)₆][CuBr₂X₂]·10H₂O and triclinic [Ta₆Br₁₂(H₂O)₆]X₂·trans‐[Ta₆Br₁₂(OH)₄(H₂O)₂]·18H₂O (X = Cl, Br, NO₃) cocrystallize in aqueous solutions of [Ta₆Br₁₂]²⁺ in the presence of Cu²⁺ ions. The crystal structures of [Ta₆Br₁₂(H₂O)₆]Cl₂·trans‐[Ta₆Br₁₂(OH)₄(H₂O)₂]·18H₂O ( 1 ) and [Ta₆Br₁₂(H₂O)₆]Br₂·trans‐[Ta₆Br₁₂(OH)₄(H₂O)₂]·18H₂O ( 3 )have been solved in the triclinic space group P&1macr; (No. 2). Crystal data: 1 , a = 9.3264(2) Å, b = 9.8272(2) Å, c = 19.0158(4) Å, α = 80.931(1)?, β = 81.772(2)?, γ = 80.691(1)?; 3 , a = 9.3399(2) Å, b = 9.8796(2) Å, c = 19.0494(4) Å; α = 81.037(1)?, β = 81.808(1)?, γ = 80.736(1)?. 1 and 3 consist of two octahedral differently charged cluster entities, [Ta₆Br₁₂]²⁺ in the [Ta₆Br₁₂(H₂O)₆]²⁺ cation and [Ta₆Br₁₂]⁴⁺ in trans‐[Ta₆Br₁₂(OH)₄(H₂O)₂]. Average bond distances in the [Ta₆Br₁₂(H₂O)₆]²⁺ cations: 1 , Ta‐Ta, 2.9243 Å; Ta‐Brⁱ , 2.607 Å; Ta‐O, 2.23 Å; 3 , Ta‐Ta, 2.9162 Å; Ta‐Brⁱ , 2.603 Å; Ta‐O, 2.24 Å. Average bond distances in trans‐[Ta₆‐Br₁₂(OH)₄(H₂O)₂]: 1 , Ta‐Ta, 3.0133 Å; Ta‐Brⁱ, 2.586 Å; Ta‐O(OH), 2.14 Å; Ta‐O(H₂O), 2.258(9) Å; 3 , Ta‐Ta, 3.0113 Å; Ta‐Brⁱ, 2.580 Å; Ta‐O(OH), 2.11 Å; Ta‐O(H₂O), 2.23(1) Å. The crystal packing results in short O···O contacts along the c axes. Under the same experimental conditions, [Ta₆Cl₁₂]²⁺ oxidized to [Ta₆Cl₁₂]⁴⁺ , whereas [Nb₆X₁₂]²⁺ clusters were not affected by the Cu²⁺ ion.     

Pentastrontium Tris[tetraoxovanadate(V)] catena‐Monoxocuprate(I), Sr5(VO4)3(CuO) – An Apatite Derivative with Inserted Linear 1Ë[CuO]1– Chains

Sr₅(VO₄)₃(CuO) was prepared via solid state reactions from mixed powders of the metal oxides or carbonates in corundum crucibles in air (1173–1740 K). The compound is transparent and stable in air. The color changes with the preparation temperature from light gray (1173 K) to gray (1740 K). The crystal structure (space group P6₃/m, No. 176; Z = 2; a = 10.126 Å, c = 7.415 Å) is a derivative of the apatite Ca₅(PO₄)₃OH, and is characterized by isolated [VO₄]^3– anions (d(V–O) = 1.710 Å) and infinite linear ^1∞[CuO]^1– chains (d(Cu–O) = 1.854 Å) inserted in the channels parallel to the hexagonal axis. The compound prepared at 1740 K contains vacancies at the copper and oxygen positions of the linear chains (about 10% and 5%, respectively).     

Syntheses,Characterizations, and Crystal Structures of Two New Organically Templated Borates

Two new organically templated borates, [H₂DAB][B₇O₉(OH)₅]·2H₂O ( 1 ) and [H₂DAB][B₇O₁₀(OH)₃] ( 2 ), have been synthesized under mild conditions in the presence of DAB acting as structure‐directing agent (DAB = 1,4‐diaminobutane). The structures were determined by single crystal X‐ray diffraction and further characterized by FTIR, elemental analysis, and thermogravimetric analysis. Both 1 and 2 crystallize in the same triclinic system, space group (No. 2); 1: a = 8.238(4) Å, b = 8.348 (5) Å, c = 14.574(8) Å, a = 101.050(3)°, β = 92.313(7)°, γ = 112.694(5)°, V = 900.3(8) ų, Z = 2; 2: a = 8.8769(3) Å, b = 9.3204(2) Å, c = 10.2204(5) Å, α = 74.474(2)°, β = 85.292(5)°, γ = 72.730(2)°, V = 778.01(5) ų, Z = 2. The structure of 1 consists of [B₇O₉(OH)₅]^2? groups, which represents the first example of organically templated heptaborate. The structure exhibits interesting hydrogen‐bonded network formed by borate polyanion [B₁₄O₂₀(OH)₆]^4?, which can be regarded as being constructed from the dehydration of the FBBs in 1 . The diprotonated organic amines are filled in the free space of the hydrogen‐bonded network and interact with the inorganic framework by extensive hydrogen bonds.     

Synthesis and Crystal Structure of SrFe[BP2O8(OH)2]

SrFe[BP₂O₈(OH)₂] was synthesised under mild hydrothermal conditions. The crystal structure was determined from single–crystal X–ray diffraction data: triclinic, space group P (No. 2), a = 6.6704(12) Å, b = 6.6927(13) Å, c = 9.3891(19) Å, α = 109.829(5)°, β = 102.068(6)°, γ = 103.151(3)°, V = 364.74(12) ų and Z = 2. The crystal structure of SrFe[BP₂O₈(OH)₂] contains isolated borophosphate oligomers, [BP₂O₈(OH)₂]^5–, which are interconnected by Fe^IIIO₄(OH)₂ coordination octahedra. The resulting three–dimensional framework is characterised by elliptical channels running along [011]. Strontium takes positions inside the channels.     

SYNTHESIS OF ONE-AND TWO-DIMENSIONAL ZINC AND CADMIUM COMPLEXES WITH 4, 4′-BIPY

Abstract

The zinc(II) and cadmium(II) complexes [Zn(4, 4′-bipy)(SCN)₂]_∞ 1 and [Cd(4, 4′-bipy)-(SCN)₂]_n 2 have been synthesized and their crystal structures determined by X-ray crystallography. Complex 1 is monoclinic, space group C2/c, with a = 18.076(5), b = 5.190(1), c = 17.315(4)Å; β = 115.54(2), V = 1465.8(8)ų, calculated density 1.530gcm^?3, Z = 4. In this compound, the rod-like ligand 4, 4′-bipy bridges Zn(II) centres, and the NCS groups are terminally coordinated. (N-Zn-N) is 108.5°, resulting in the formation of a zigzag Zn-bipy-Zn chain. These chains are arranged in parallel fashion. The 4, 4′-bipy ligands of adjacent layers are separated by 3.95 (Å). Complex 2 is monoclinic, space group C2/c, a = 11.902(2), b = 11.745(2), c = 10.500(2)Å; β = 109.71(3), V = 1381.8(4)ų calculated density 1.849gcm^?3, Z = 4. In this structure, the cadmium(II) ion is slightly distorted octahedral and the SCN groups act as doubly bridging ligands connecting cadmium atoms to form zigzag chains, separated by 4, 4′-bipy to create two-dimensional planes.     

A cobalt(III) compound of a 13‐membered cyclic tetra­amine: trans‐(12,12‐dimethyl‐1,4,7,10‐tetra­aza­cyclo­tetra­decane)diisothio­cyanato­cobalt(III) tetra­isothio­cyanato­zinc(II) ethanol solvate

The title compound, [Co(NCS)₂(C₁₁H₂₆N₄)]₂[Zn(NCS)₄]·C₂H₅OH, has two similar cations with the Co^III atom coordinated in a planar fashion by the 13‐membered cyclic tetra­amine, in the 1R,4S,7R,10S configuration, and with trans isothio­cyanate ligands. The six‐membered chelate ring is in a chair conformation, with one axially and one equatorially oriented methyl substituent [mean Co—N = 1.948 (2) Å]. The `opposite' chelate ring (N<sup>4</sup> and N<sup>7</sup>) is in an eclipsed conformation [mean Co—N = 1.928 (2) Å], and the `side' chelate rings have gauche conformations. The mean Co—N_NCS distance is 1.928 (2) Å. Both cations have one Co—N—C group nearly linear and the other appreciably bent, with mean Co—N—C angles of 178.7 (1) and 160.4 (1)°, respectively. The [Zn(NCS)₄]²⁻ anion is approximately tetra­hedral, with Zn—N = 1.951 (1)–1.986 (1) Å, N—Zn—N = 104.5 (1)–111.9 (1)° and Zn—N—C = 152.5 (1)–179.4 (1)°. One NH group is hydrogen bonded to the ethanol O atom and the other NH groups are bonded to thio­cyanate S atoms, forming a network.     

1,4,7-Trithiacyclononane as a Tridentate Ligand for Complexation of Heavy-Metal Ions: Synthesis and Complexation Studies of Mesocyclic and Macrocyclic Polythioethers IV

Bis octahedral complexes of 1,4,7-trithiacyclononane (9-ane-S₃) with Group 12 metal ions Zn(II), Cd(II), and Hg(II), as well as Pb(II), have been prepared. Two equivalents of 9-ane-S₃ react with Zn(BF₄)₂·6H₂O, Cd(ClO₄)₂·6H₂O, Hg(ClO₄)₂·3H₂O, and Pb(ClO₄)₂. 3H₂O, respectively, to give stable crystalline complexes of the formula [M(9-ane-S₃)₂]²+ 2X⁻. Single-crystal X-ray structures of the zinc and mercury complexes have been determined. The zinc complex crystallizes in the orthorhombic space group Pbca with four molecules per unit cell (a = 9.219(3) Å, b = 15.400(5) Å, and c = 19.965(10)Å; R = 7.6%) whereas the mercury complex crystallizes in the monoclinic space group P2₁/c with two molecules per unit cell (a = 10.400(3) Å, b = 15.190(4) Å, c = 9.533(3) Å, and p = 99.09(3)°; R = 5.2%). In each structure, the metal atom is located on a crystallographic center of inversion and is octahedrally surrounded by six sulfur atoms provided by the two facially coordinating tridentate ligands. Reaction of 9-ane-S₃ with RuCl₃·xH₂O displaces chloride ions with concomitant reduction of Ru(III) to Ru(II), giving the octahedral thioether complex, [Ru(9-ane-S₃)₂]Cl₂·4H₂O. Reaction of the ligand with RhCl₃, on the other hand, gives (9-ane-S₃)RhCl₃. A single-crystal X-ray structure determination has been done on the Ru(II) complex (triclinic space group P 1 ̅; a = 7.652(1) Å, b = 8.946(1) Å, c = 9.042(1) Å, α = 93.43(1)°, β = 103.43(1)°, and γ = 107.79(1)°; R = 2.8%) and this complex is also octahedral with the metal center at an inversion center.     

Das erste Vanadium(III)‐Borophosphat: Darstellung und Kristallstruktur von CsV3(H2O)2[B2P4O16(OH)4]

The First Vanadium(III) Borophosphate: Synthesis and Crystal Structure of CsV₃(H₂O)₂[B₂P₄O₁₆(OH)₄] CsV₃(H₂O)₂[B₂P₄O₁₆(OH)₄] was prepared under mild hydrothermal conditions (T = 165 °C) from mixtures of CsOH_(aq), VCl₃, H₃BO₃, and H₃PO₄ (molar ratio 1 : 1 : 1 : 2). The crystal structure was determined by X‐ray single crystal methods (monoclinic; space group C2/m, No. 12): a = 958.82(15) pm, b = 1840.8(4) pm, c = 503.49(3) pm; β = 110.675(4)°; Z = 2. The anionic partial structure contains oligomeric units [BP₂O₈(OH)₂]^5–, which are built up by a central BO₂(OH)₂ tetrahedron and two PO₄ tetrahedra sharing common corners. V^III is octahedrally coordinated by oxygen of adjacent phosphate tetrahedra and OH groups of borate tetrahedra as well as oxygen of phosphate tetrahedra and H₂O molecules, respectively (coordination octahedra VO₄(OH)₂ and VO₄(H₂O)₂). The oxidation state +3 for vanadium was confirmed by measurements of the magnetic susceptibility. The trimeric borophosphate groups are connected via vanadium centres to form layers with octahedra‐tetrahedra ring systems, which are likewise linked via V^III‐coordination octahedra. Overall, a three‐dimensional framework constructed from VO₄(OH)₂ and VO₄(H₂O)₂ octahedra as well as BO₂(OH)₂ and PO₄ tetrahedra results. The structure contains channels running along [001], which are occupied by Cs⁺ in a distorted octahedral coordination (CsO₄(H₂O)₂).     

Crystal Structure of the Bis[zinc(II)-hydroxide-(μ-perchlorate)-triaqua] Complex

Colorless single crystals of the title compound were accidentally obtained by a reaction of p-sulfophenylalanine with zinc perchlorate. The crystal structure (monoclinic, P2₁/c, Z = 4, a = 5.9031(7), b = 13.5404(16), c = 9.7932(8) Å, β = 126.438(5)°, V = 629.74(12) ų, R₁[I>2σ(I)] = 0.0276, wR₂(all) = 0.0844) reveals a discrete dinuclear [Zn(OH)(μ-ClO₄)(H₂O)₃]₂ in which each perchlorate anion acts as a bidentate bridging linker to bind two Zn atoms whereas the hydroxy group is a terminal group. Thus, the local surrounding around the zinc atom can be best described as a slightly distorted octahedron.     

Synthesis and Crystal Structure of [C10N2H10]2[P2Mo5O21(OH)2]·2H2O

The crystal structure of [C₁₀N₂H₁₀]₂[P₂Mo₅O₂₁(OH)₂] · 2H₂O, contains the heteropolyanion, [P₂Mo₅O₂₁(OH)₂]^4—, together with diprotonated 4, 4′‐bipyridine. The heteropolyanion is built up from five MoO₆ octahedra sharing four common edges and one common corner, capped by two PO₃(OH) tetrahedra. The structure is stabilized by hydrogen bonds involving the hydrogen atoms of the 4, 4′‐bipyridine, water molecules and the oxygen atoms of the pentamolybdatobisphosphate. This is the first example that this kind of cluster could be isolated in the presence of a poly‐functional aromatic molecule ion. Crystal data: triclinic, P1¯ (No. 2), a = 9.983(2)Å, b = 11.269(2)Å, c = 17.604(4)Å, α = 73.50(3)°, β = 84.07(3)°, γ = 67.96(3)°; V = 1760.0(6)ų; Z = 2; R₁ = 0.037 and wR₂ = 0.081, for 9138 reflections [I > 2σ(I)].     

Syntheses and Structures of Zinc(II) Co‐Ordination Polymers Bridged by Flexible Bidentate Nitrogen Ligands

The reaction of Zn(NO₃)₂·6H₂O and bpp (bpp = 1,3‐Bis(4‐pyridyl)pronpane) in CH₃OH afforded the complex [Zn(bpp)(NO₃)₂]_n, 1 . The IR has been recorded and the structure has been determined. Crystal data for 1: Space group P2(1)/n, a = 11.749(1), b = 11.413(1), c = 11.942(1) Å, β = 96.06(6)°. V = 1592.5(3) ų, Z = 4 with final residuals R1 = 0.0484 and wR2 = 0.0984. The complexes show supramolecular structure in the solid state by intermolecular hydrogen bonding interaction.     

Synthesis and Crystal Structure of Cs(VO2)3(TeO3)2, a New Layered Cesium Vanadium(V) Tellurite

Synthetic Cs(VO₂)₃(TeO₃)₂ is built up from infinite sheets of distorted octahedral V^VO₆ groups, sharing vertices. These octahedral layers are “capped” by Te atoms (as parts of pyramidal [Te^IVO₃]^2– groups) on both faces of each V/O sheet, with inter‐layer, 12‐coordinate, Cs⁺ cations providing charge compensation. Cs(VO₂)₃(TeO₃)₂ is isostructural with M(VO₂)₃(SeO₃)₂ (M = NH₄, K). Crystal data: Cs(VO₂)₃(TeO₃)₂, M_r = 732.93, hexagonal, space group P6₃ (No. 173), a = 7.2351(9) Å, c = 11.584(2) Å, V = 525.1(2) ų, Z = 2, R(F) = 0.030, wR(F ²) = 0.063.     

[N,N′‐Bis(3‐aminopropyl)ethylenediamine‐κ4N,N′,N′′,N′′′](trithiocyanurato‐κ2N,S)zinc(II) ethanol solvate

In the crystal structure of the title compound, [N,N′‐bis(3‐­amino­propyl)­ethyl­enedi­amine‐κ⁴N,N′,N′′,N′′′][1,3,5‐triazine‐2,4,6(1H,3H,5H)‐tri­thionato(2−)‐κ²N,S]­zinc(II) ethanol sol­vate, [Zn(C₈H₂₂N₄)₂(C₃HN₃S₃)]·C₂H₆O, the Zn^II atom is octa­hedrally coordinated by four N atoms [Zn—N = 2.104 (2)–2.203 (2) Å] of a tetradentate N‐donor N,N′‐bis(3‐­amino­propyl)­ethyl­enedi­amine (bapen) ligand and by two S and N atoms [Zn—S = 2.5700 (7) Å and Zn—N = 2.313 (2) Å] of a tri­thio­cyanurate(2−) (ttcH²⁻) dianion bonded as a bidentate ligand in a cis configuration. The crystal structure of the compound is stabilized by a network of hydrogen bonds.     

Crystal Structures of the Europium and Yttrium Hydroxychromates Eu(OH)(CrO4) and Y(OH)(CrO4); Structural Evolution as a Function of the Ln3+ Ionic Radius

The compounds Eu(OH)(CrO₄) and Y(OH)(CrO₄) were obtained under hydrothermal conditions and characterized by single‐crystal X‐ray diffraction analysis. They are isostructural and crystallize in the monoclinic system, space group P2₁/n (no. 14) with lattice parameters a = 8.278(1) Å, b = 11.400(2) Å, c = 8.393(1) Å, β = 93.76(2)°, V = 790.3(2) Å³, Z = 4, d = 4.79 g · cm^–3 for Eu(OH)(CrO₄) and a = 8.151(1) Å, b = 11.362(2) Å, c = 8.285(1) Å, β = 94.23(1)°, V = 765.2(2) Å³, Z = 4, d = 3.85 g · cm^–3 for Y(OH)(CrO₄). The [EuO₈] polyhedra form infinite double chains along the a direction, which are connected by common edges and corners. These double chains are related together in the two other directions by the [CrO₄]^2– tetrahedra to form a three‐dimensional network in which channels appear parallel to the [100] direction. We examine the structural evolution, as a function of the Ln³⁺ ionic radius, in the series Ln(OH)(CrO₄) compounds (with Ln = Nd, Eu, Gd, Tb, Er, Yb) and Y(OH)(CrO₄). To determine the best coordination number of each lanthanide and yttrium ions, different calculations of bond valence sum were realized.     

MOLECULAR RECOGNITION OF AN ORGANIC MOLECULE BY BIS(TETRAFLUOROBORATE)ZINC(II). SYNTHESIS AND CRYSTAL STRUCTURE OF {[Zn(phen)3](BF4)2}2·MNA·(H2O)1.5

Abstract

The 2:1 adduct {[Zn(phen)₃](BF₄)₂}₂·MNA·(H₂O)_1.5 (1) (where phen = 1,10-phenanthroline and MNA = 2-methyl-4-nitrobenzenamine) was prepared by self-assembly and characterized by X-ray crystallography. The central zinc atom in two non-equivalent [Zn(phen)₃]²⁺ cations exhibits distorted octahedral geometry with Zn-N bond distances of 2.151(6)-2.194(6) Å and 2.136(6)-2.210(6) Å, respectively. The 2-methyl-4-nitrobenzenamine molecule is connected with bis(tetrafluoroborate)tris(1,10-phenanthroline)zinc(II) through a hydrogen bond (N13-H13a…F23? 3.044 Å, ?1 - x, 1 - y, - z). High shape specificity was observed in the recognition process.