Synthesis and Characterization of the Chain Borosulfates (NH4)3[B(SO4)3] and Sr[B2(SO4)4]

Two new borosulfates were obtained either by an open vessel synthesis from sulfuric acid and B(OH)₃, yielding (NH₄)₃[B(SO₄)₃] or from solvothermal synthesis in oleum enriched sulfuric acid and B(OH)₃, yielding Sr[B₂(SO₄)₄]. (NH₄)₃[B(SO₄)₃] crystallizes homeotypic to K₃[B(SO₄)₃] in space group Ibca (Z = 8, a = 728.58(3) pm, b = 1470.84(7) pm, c = 2270.52(11) pm), comprising open branched vierer single chains {¹_∞[B(SO₄)₂(SO₄)_2/2]^3–}. Sr[B₂(SO₄)₄] crystallizes as an ordered variant of Pb[B₂(SO₄)₄] in space group Pnna (Z = 4, a = 1257.4(4) pm, b = 1242.1(4) pm, c = 731.9(2) pm), consisting of loop branched vierer single chains {¹_∞[B(SO₄)_4/2]^2–}. Vibrational spectroscopy confirms both refined structure models. Thermal analysis of the dried powders, showed a decomposition towards the binary and ternary components, whereas a thermal treatment in the presence of the mother liquor promotes a decomposition of Sr[B₂(SO₄)₄] towards Sr[B₂O(SO₄)₃].     

Ni[B2(SO4)4] and Co[B2(SO4)4]: Unveiling Systematic Trends in Phyllosilicate Analogue Borosulfates

Borosulfates are compounds analogous to silicates, with heteropolyanionic subunits of vertex-linked (SO₄)- and (BO₄)-tetrahedra. In contrast to the immense structural diversity of silicates, the number of borosulfates is yet very limited and the extent of their properties is still unknown. This is particularly true for representatives with phyllosilicate and tectosilicate analogue anionic substructures. Herein, we present Ni[B₂(SO₄)₄] and Co[B₂(SO₄)₄], two new borosulfates with phyllosilicate analogue topology. While the anionic subunits of both structures are homeotypic, the positions of the charge compensating cations differ significantly: Ni^II is located between the borosulfate layers, while Co^II—in contrast—is embedded within the layer. Detailed analysis of these two structures based on single-crystal X-ray diffraction, magnetochemical investigations, X-ray photoelectron spectroscopy, and quantum chemical calculations, unveiled the reasons for this finding. By in silico comparison with other divalent borosulfates, we uncovered systematic trends for phyllosilicate analogues leading to the prediction of new species.     

Crystal Structures of [Cu2(bpy)2(H2O)(OH)2(SO4)]·4H2O and [Cu(bpy)(H2O)2]SO4 with bpy = 2, 2′‐Bipyridine

Two sulfato Cu^II complexes [Cu₂(bpy)₂(H₂O)(OH)₂(SO₄)]· 4H₂O ( 1 ) and [Cu(bpy)(H₂O)₂]SO₄ ( 2 ) were synthesized and structurally characterized by single crystal X—ray diffraction. Complex 1 consists of the asymmetric dinuclear [Cu₂(bpy)₂(H₂O)(OH)₂(SO₄)] complex molecules and hydrogen bonded H₂O molecules. Within the dinuclear molecules, the Cu atoms are in square pyramidal geometries, where the equatorial sites are occupied by two N atoms of one bpy ligand and two O atoms of different μ₂—OH groups and the apical position by one aqua ligand or one sulfato group. Through intermolecular O—H···O and C—H···O hydrogen bonds and intermolecular π—π stacking interactions, the dinuclear complex molecules are assembled into layers, between which the hydrogen bonded H₂O molecules are located. The Cu atoms in 2 are octahedrally coordinated by two N atoms of one bpy ligand and four O atoms of two H₂O molecules and two sulfato groups with the sulfato O atoms at the trans positions and are bridged by sulfato groups into ¹[Cu(bpy)(H₂O)₂(SO₄)_2/2] chains. Through the interchain π—π stacking interactions and interchain C—H···O hydrogen bonds, the resulting chains are assembled into bi—chains, which are further interlinked into layers by O—H···O hydrogen bonds between adjacent bichains.     

Synthesis-Controlled Polymorphism and Optical Properties of Phyllosilicate-Analogous Borosulfates M[B2(SO4)4] (M=Mg,Co)

Increased synthetic control in borosulfate chemistry leads to the access of various new compounds. Herein, the polymorphism of phyllosilicate-analogous borosulfates is unraveled by adjusting the oleum (65 % SO₃) content. The new polymorphs β-Mg[B₂(SO₄)₄] and α-Co[B₂(SO₄)₄] both consist of similar layers of alternating borate and sulfate tetrahedra, but differ in the position of octahedrally coordinated cations. The α-modification comprises cations between the layers, whereas in the β-modification cations are embedded within the layers. With this new synthetic approach, phase-pure compounds of the respective polymorphs α-Mg[B₂(SO₄)₄] and β-Co[B₂(SO₄)₄] were also achieved. Tanabe–Sugano analysis of the Co²⁺ polymorphs reveal weak ligand field splitting and give insights into the coordination behavior of the two-dimensional borosulfate anions for the first time. DFT calculations confirmed previous in silico experiments and enabled an assignment of the polymorphs by comparing the total electronic energies. The compounds are characterized by single-crystal XRD, PXRD, FTIR, and UV/Vis/NIR spectroscopy, thermogravimetric analysis (TGA), and density functional theory (DFT) calculations.     

Synthesis and Characterization of Gd2[Pt2(SO4)4(HSO4)2](HSO4)2

Red single crystals of Gd₂[Pt₂(SO₄)₄(HSO₄)₂](HSO₄)₂ (triclinic, , Z = 1, a = 844.02(9), b = 908.50(9), c = 939.49(8) pm, α = 107.73(1)°, β = 112.10(1)°, γ = 103.53(1)°) were obtained by the reaction of [Gd(NO₃)(H₂O)₇][PtCl₆]·4H₂O with sulfuric acid at 320 °C in a sealed glass ampoule. In the crystal structure, Pt₂ dumbbells are coordinated by four chelating sulfate groups and two monodentate hydrogensulfate ions. Two further HSO₄^? ions are not bonded to the Pt₂ dumbbell. The Gd³⁺ ions are eightfold coordinated by oxygen atoms. The IR data of Gd₂[Pt₂(SO₄)₄(HSO₄)₂](HSO₄)₂ are typical for these type of compounds. The thermal decomposition of the compound leads to elemental platinum and Gd₂O₃.     

ASb2(SO4)2(PO4) (A = H3O+, K,Rb): Layered Structure Containing Ordered Sulfate and Phosphate Anions

Three compounds ASb₂(SO₄)₂(PO₄) (A = H₃O⁺, K, Rb) were obtained from the reactions of Sb₂O₃, A₂CO₃ (A = Li, Rb) or K₂SO₄ and NH₄H₂PO₄ in H₂SO₄ (98 %) at 220–250 °C. Their structures were determined by single‐crystal X‐ray diffraction. All compounds crystallize in the triclinic space group P$\bar{1}$ (no.2) and are isostructural. The crystal structures consist of two‐dimensional ²_∞[Sb₂(SO₄)₂(PO₄)]^– anionic layers and alkali cations, which are located between anionic layers. The anionic layers are composed of [SbO₄] ψ‐trigonal bipyramids, [SbO₅] ψ octahedra, [SO₄] tetrahedra, and [PO₄] tetrahedra. All compounds are characterized by solid state UV/Vis/NIR diffuse reflectance spectra, FT‐IR spectroscopy, and Raman spectroscopy.     

Synthese und Struktur neuer Natriumhydrogensulfate Na(H3O)(HSO4)2; Na2(HSO4)2(H2SO4) und Na(HSO4)(H2SO4)2

Synthesis and Structure of New Sodium Hydrogen Sulfates Na(H₃O)(HSO₄)₂, Na₂(HSO₄)₂(H₂SO₄), and Na(HSO₄)(H₂SO₄)₂ Three acidic sodium sulfates have been synthesized from the system sodium sulfate/sulfuric acid and have been crystallographically characterized. Na(H₃O)(HSO₄)₂ ( A ) crystallizes in the space group P2₁/c with the unit cell parameters a = 6.974(2), b = 13.086(2), c = 8.080(3) Å, α = 105.90(4)°, V = 709.1 Å3, Z = 4. Na₂(HSO₄)₂(H₂SO₄) ( B ) is orthorhombic (space group Pna2₁) with the unit cell parameters a = 9.970(2), b = 6.951(1), c = 13.949(3) Å, V = 966.7 ų and Z = 4. Na(HSO₄)(H₂SO₄)₂ ( C ) crystallizes in the triclinic space group P1 with the unit cell parameters a = 5.084(1), b = 8.746(1), c = 11.765(3) Å, α = 68.86(2)°, β = 88.44(2)°, γ = 88.97(2)°, V = 487.8 Å3 and Z = 2. All three compounds contain SO₄ tetrahedra as HSO₄^? anions and additionally in B and C in form of H₂SO₄ molecules. The ratio H:SO₄ determines the connectivity degree in the hydrogen bond system. In A , there are zigzag chains and dimers additionally connected via oxonium ions. Complex chains consisting of cyclic trimers (two HSO₄^? and one H₂SO₄) are present in B . In structure C , several parallel chains are connected to columns due to the greater content of H₂SO₄. Sodium cations show a distorted octahedral coordination by oxygen in all three structures, the NaO₆ octahedra being “isolated” (connected via SO₄ tetrahedra only) in A . Pairs of octahedra with common edge form Na₂O₁₀ dimeric units in C . Such double octahedra are connected via common corners forming zigzag chains in B .     

Darstellung,Ramanspektren und Kristallstrukturen von V2O3(SO4)2, K[VO(SO4)2] und NH4[VO(SO4)2]

Preparation, Raman Spectra, and Crystal Structures of V₂O₃(SO₄)₂, K[VO(SO₄)₂], and NH₄[VO(SO₄)₂] The oxo-sulfato-vanadates(V) V₂O₃(SO₄)₂, K[VO(SO₄)₂], and NH₄[VO(SO₄)₂] have been prepared as crystals suitable for X-ray structure determination. In all structures sulfate acts as an unidentate ligand only toward a single vanadium atom. The structure of V₂O₃(SO₄)₂ consists of a threedimensional network of pairs of cornershared VO₆ octahedra with one terminal oxygen atom each, and SO₄ tetrahedra. All oxygen atoms of the sulfate ions are coordinated. NH₄[VO(SO₄)₂] and K[VO(SO₄)₂] are isostructural. VO₆ octahedra with one terminal oxygen atom and pairs of sulfate tetrahedra form infinite chains by corner sharing. The chains are weakly interlinked to layers. The sulfate ions are distorted towards planar SO₃ molecules and single oxygen atoms attached to vanadium. This structural detail gives an explanation for the mechanism of the reversible reaction K[VO(SO₄)₂] ? K[VO₂(SO₄)] + SO₃ at 400°C. Raman spectra of the compounds have been recorded and interpreted with respect to their structures. Crystal data: V₂O₃(SO₄)₂, monoclinic, space group P2₁/a, a = 947.2(4), b = 891.3(3), c? 989.1(4) pm, β = 104.56(3)°, Z = 4, 878 unique data, R(R_w) = 0.039(0,033); K[VO(SO₄)₂], orthorhombic, space group P2₁2₁2₁, a = 495.3(2), b = 869.6(9), c = 1 627(1)pm, Z = 4, 642 unique data, R(R_w) = 0,11(0,10); NH₄[VO(SO₄)₂], orthorhombic, space group P2₁2₁2₁, a = 495.3(1), b = 870.0(2), c = 1 676.7(4)pm, Z = 4, 768 unique data, R(R_w) = 0.088(0.083).     

Pt2(HSO4)2(SO4)2, the First Binary Sulfate of Platinum

Red single crystals of Pt₂(HSO₄)₂(SO₄)₂ were obtained by the reaction of elemental platinum with conc. sulfuric acid at 350 °C in sealed glass ampoules. The crystal structure (monoclinic, P2₁/c, Z = 2, a = 868.6(2), b = 826.2(1), c = 921.8(2) pm, β=116.32(1)°, R_all = 0.0348) shows dumbbell shaped Pt₂⁶⁺ cations which are coordinated by four SO₄^2— and two HSO₄^— ions. Each of the sulfate ions is attached to another Pt₂⁶⁺ ion yielding layers according to equation/tex2gif-stack-1.gif[Pt₂(SO₄)_4/2(HSO₄)_2/1]. The layers are connected by hydrogen bonds with the OH group of the hydrogensulfate ion as donor and the non‐bonding oxygen atom of the sulfate ion as acceptor.     

A pseudo‐merohedrally twinned rare‐earth sulfate: K6[Ce(HSO4)2(SO4)4]·H2O,a novel structure type

A novel structure type of an acidic rare‐earth sulfate, hexa­potassium cerium dihydrogensulfate tetra­sulfate monohydrate, is reported. The crystal is twinned, mimicking tetra­gonal symmetry. The Ce^IV atom is nine‐coordinate, connecting to one corner‐sharing and four edge‐sharing sulfate groups. One of the potassium ions is disordered over two general positions. The compound is unique as it contains rare‐earth monomers, [Ce(HSO₄)(SO₄)₄]⁵⁻. The structure is composed of these monomers, water mol­ecules, discrete hydrogensulfate ions and potassium ions held together by ionic inter­actions. There are two types of alternating layers in the structure, with compositions [K₄Ce(HSO₄)(SO₄)₄]⁻ and [K₂(HSO₄)(H₂O)]⁺.     

Phosphanimin- und Phosphaniminato-Komplexe von Bor. Synthese und Kristallstrukturen von [BF3(Me3SiNPEt3)], [BCl2(NPPh3)]2, [BCl2(NPEt3)]2, [B2Cl3(NPEt3)2]+BCl4− und [B2Cl2(NPiPr3)3]+BCl4−

Phosphaneimine and Phosphoraneiminato Complexes of Boron. Synthesis and Crystal Structures of [BF₃(Me₃SiNPEt₃)], [BCl₂(NPPh₃)]₂, [BCl₂(NPEt₃)]₂, [B₂Cl₃(NPEt₃)₂]⁺BCl₄^?, and [B₂Cl₂(NPⁱPr₃)₃]⁺BCl₄^? The title compounds have been prepared from the corresponding silylated phosphaneimines and boron trifluoride etherate and boron trichloride, respectively. The compounds form white moisture sensitive crystals, which were characterized by ¹¹B-nmr-spectroscopy, IR-spectroscopy and by crystal structure determinations. [BF₃(Me₃SiNPEt₃)] : Space group P2₁/c, Z = 4, R = 0.032 for reflections with I > 2σ(I). Lattice dimensions at ?70°C: a = 1361.0, b = 819.56, c = 1422.5 pm, β = 109.86°. The donor acceptor complex forms monomeric molecules with a B? N bond length of 157.8 pm. [BCl₂(NPPh₃)]₂ · 2 CH₂Cl₂ : Space group P2₁/c, Z = 2, R = 0.049 for reflections with I > 2σ(I). Lattice dimensions at ?50°C: a = 1184.6, b = 2086.4, c = 843.0 pm, β = 96.86°. The compound forms centrosymmetric dimeric molecules in which the boron atoms are linked to B₂N₂ four-membered rings with B? N distances of 152.7 pm via μ₂-N bridges of the NPPh₃ groups. [BCl₂(NPEt₃)]₂ : Space group Pbca, Z = 4, R = 0.029 for reflections with I > 2σ(I). Lattice dimensions at ?90°C: a = 1269.5, b = 1138.7, c = 1470.3 pm. The compound has a molecular structure corresponding to the phenyl compound with B? N ring distances of 151.0 pm. [B₂Cl₃(NPEt₃)₂]⁺BCl₄^? : Space group Pbca, Z = 8, R = 0.034 for reflections with I > 2σ(I). Lattice dimensions at ?70°C: a = 1309.3, b = 1619.8, c = 2410.7 pm. Within the cations the boron atoms are linked to planar, asymmetrical B₂N₂ four-membered rings with B? N distances of 155.1 and 143.1 pm via the μ₂-N atoms of the NPEt₃ groups. [B₂Cl₂(NPⁱPr₃)₃]⁺BCl₄^? · CH₂Cl₂: Space group Pna2, Z = 4, R = 0.033 for reflections with I > 2σ(I). Lattice dimensions at ?70°C: a = 1976.5, b = 860.2, c = 2612.7 pm. Within the cations the boron atoms are linked to planar, asymmetrical B₂N₂ four-membered rings with B? N distances of 153.7 and 150.5 pm via the μ₂-N atoms of two of the NPⁱPr₃ groups. The third NPⁱPr₃ group is terminally connected to the sp²-hybridized boron atom with a B? N distance of 133.5 pm and with a B? N? P bond angle of 165.3°.     

The Borosulfates K4[BS4O15(OH)], Ba[B2S3O13], and Gd2[B2S6O24]

K₄[BS₄O₁₅(OH)], Ba[B₂S₃O₁₃], and Gd₂[B₂S₆O₂₄] were obtained by a new synthetic approach. The strategy involves initially synthesizing the complex acid H[B(HSO₄)₄] which is subsequently reacted in an open system with anhydrous chlorides of K, Ba, and Gd to the respective borosulfates and a volatile molecule (HCl). Furthermore, protonated borosulfates should be accessible by appropriate stoichiometry of the starting materials, particularly in closed systems, which inhibit deprotonation of H[B(HSO₄)₄] via condensation and dehydration. This approach led to the successful synthesis of the first divalent and trivalent metal borosulfates (Ba[B₂S₃O₁₃] with band‐silicate topology and Gd₂[B₂S₆O₂₄] with cyclosilicate topology) and the first hydrogen borosulfate K₄[BS₄O₁₅(OH)].     

Phosphaniminato-Komplexe von Bor. Synthese und Kristallstrukturen von [BBr2(NPMe3)]2, [B2Br3(NPiPr3)2]Br, [B2(NPEt3)4]Br2, [B2Br2(NPPh3)3]BBr4 und [{B2(NMe2)2}2(NPEt3)2]Cl2

Phosphoraneiminato Complexes of Boron. Syntheses and Crystal Structures of [BBr₂(NPMe₃)]₂, [B₂Br₃(NPⁱPr₃)₂]Br, [B₂(NPEt₃)₄]Br₂, [B₂Br₂(NPPh₃)₃]BBr₄ and [{B₂(NMe₂)₂}₂(NPEt₃)₂]Cl The bromoderivatives of the title compounds are prepared from the corresponding silylated phosphoraneimines Me₃SiNPR₃ and boron tribromide. The boron subcompound [{B₂(NMe₂)₂}₂(NPEt₃)₂]Cl₂ derives from Me₃SiNPEt₃ and B₂Cl₂(NMe₂)₂. All complexes are characterized by NMR and IR spectroscopy as well as by crystal structure determinations. [BBr₂(NPMe₃)]₂ (1): Space group P2₁/n, Z = 2, R = 0.031. Lattice dimensions at ?50°C: a = 723.8, b = 894.2, c = 1305.4 pm, β = 92.35°. 1 forms centrosymmetric molecules in which the boron atoms are linked via μ₂-N bridges of the NPMe₃^? groups of from B₂N₂ four-membered rings with B? N distances of 149.9 and 150.9 pm. B₂Br₃(NPⁱPr₃)₂]Br (2): Space group P2₁, Z = 2, R = 0.059. Lattice dimensions at ?80°C: a = 817.6, b = 2198.7, c = 851.5 pm, β = 115.09°. In the cations of 2 the boron atoms are lined via the μ₂-N atoms of the NPⁱPr₃^? groups to form planar, asymmetric B₂N₂ four-membered rings with B? N distances of 143 and 156 pm. [B₂(NPEt₃)₄[Br₂·4CH₂Cl₂ (3): Space group C2/c, Z = 4, R = 0.042. Lattice dimensions at ?50°C: a = 1946.1, b = 1180.3, c = 2311.3 pm, β = 101.02°. The structure contains centrosymmetric dications in which both the boron atoms are lined by the N atoms of two of the NPEt₃^? groups to form a B₂N₂ four-membered ring with B? N distances of 149.6 pm. The remaining two NPEt₃^? groups are terminally bonded with very short B? N distances of 133.5 pm. B₂Br₂(NPPh₃)₃]BBr₄ (4): Space group P1 , Z = 2, R = 0.065. Lattice dimension at ?50°C: a = 1025.7, b = 1496.1, c = 1807.0 pm, α = 85.09°, β = 82.90°, γ = 82.72°. In the cation the boron atoms are lined via the μ₂-N atoms of two of the NPPh₃^? groups to form a nearly planer B₂N₂ four-membered ring with B? N distances of 149.3-153.1 pm. The third NPPh₃³ group is terminally connected with teh sp² hybridized boron atom and with a B? N distance of 134.1 pm along with an almost linear BNP bond angle of 173.6°. [{B₂(NMe₂)₂}₂(NPEt₂)₂]Cl₂ · 3CH₂Cl₂ (5): Space group C2/c, Z = 4, R = 0.098. Lattice dimensions at ?70°C: a = 1557.9, b = 1294.7, c = 2122.9 pm, β = 96.08°. The structure of 4 contains centrosymmetric dications in which two by two B-B dumb-bells are linked via the μ₂-N atoms of the two NEPt₃^? groups to form B₄N₂ six-membered rings with B? N distances of 150 and 156 pm and B-B distances of 173 pm. The B? N distances of the terminally bonded NMe₂^? groups correspond to 138 pm double bonds.     

Synthese und Kristallstruktur von Hydrogensulfaten einwertiger Metalle – Ag(H3O)(HSO4)2, Ag2(HSO4)2(H2SO4), AgHSO4 und Hg2(HSO4)2

Synthesis and Crystal Structure of Metal(I) Hydrogen Sulfates – Ag(H₃O)(HSO₄)₂, Ag₂(HSO₄)₂(H₂SO₄), AgHSO₄, and Hg₂(HSO₄)₂ Hydrogen sulfates Ag(H₃O)(HSO₄)₂, Ag₂(HSO₄)₂ · (H₂SO₄), and AgHSO₄ have been synthesized from Ag₂SO₄ and sulfuric acid. Hg₂(HSO₄)₂ was obtained from metallic mercury and 96% sulfuric acid as starting materials. The compounds were characterized by X‐ray single crystal structure determination. Ag(H₃O)(HSO₄)₂ belongs to the structure type of Na(H₃O)(HSO₄). The silver atom is coordinated by 6 + 2 oxygen atoms. In the structure, there are dimers and chains of hydrogen bonded HSO₄^– tetrahedra. Dimers and chains are connected by the H₃O⁺ ion to form a three dimensional hydrogen network. Ag₂(HSO₄)₂(H₂SO₄) crystallizes isotypic to Na₂(HSO₄)₂(H₂SO₄). The coordination number of silver is 6 + 1. The structure of Ag₂(HSO₄)₂(H₂SO₄) is characterized by hydrogen bonded trimers of HSO₄^– tetrahedra, which are further connected to chains. For the recently published structure of AgHSO₄ the hydrogen bonding system was discussed. There are tetrameres and chains, connected by bifurcated hydrogen bonds. The structure of Hg₂(HSO₄)₂ contains Hg₂²⁺ cations with Hg–Hg distance of 2.509 Å. Every mercury atom is coordinated by one oxygen atom at shorter distance (2.18 Å) and three ones at longer distances (2.57 to 3.08 Å). The HSO₄^– tetrahedra form zigzag chains by hydrogen bonds.     

An Organically Templated Copper Pentaborate with Infinite Metallo-chains:[Cu(C3N2H4)4][Cu(CH3COO)2(C3N2H4)2(H2O)2][B5O6(OH)4]2

A novel organically templated copper pentaborate, [Cu(C₃N₂H₄)₄][Cu(CH₃COO)₂(C₃N₂H₄)₂(H₂O)₂]‐ [B₅O₆(OH)₄]₂, was synthesized by hydrothermal reaction and characterized by elemental analysis, single‐crystal X‐ray diffraction, FT‐IR spectroscopy, Raman spectroscopy and TGA. The crystal structure of this compound consists of two copper‐centered polyhedra and two discrete [B₅O₆(OH)₄]^? pentaborate anions, which are linked together through intensive hydrogen bonding interactions, forming a 3D framework with large channels along c axis. The discrete pentaborate anions form infinite layers by hydrogen bonds. Moreover, the two crystallographically different octahedral coppers are connected by common oxygen atom to form an infinite chain.     

Sulfate und Hydrogensulfate des Erbiums: Er(HSO4)3-I,Er(HSO4)3-II,Er(SO4)(HSO4) und Er2(SO4)3

Sulfates and Hydrogensulfates of Erbium: Er(HSO₄)₃-I, Er(HSO₄)₃-II, Er(SO₄)(HSO₄), and Er₂(SO₄)₃ Rod shaped light pink crystals of Er(HSO₄)₃-I (orthorhombic, Pbca, a = 1195.0(1) pm, b = 949.30(7) pm, c = 1644.3(1) pm) grow from a solution of Er₂(SO₄)₃ in conc. H₂SO₄ at 250 °C. From slightly diluted solutions (85%) which contain Na₂SO₄, brick shaped light pink crystals of Er(HSO₄)₃-II (monoclinic, P2₁/n, a = 520.00(5) pm, b = 1357.8(1) pm, c = 1233.4(1) pm, β = 92.13(1)°) were obtained at 250 °C and crystals of the same colour of Er(SO₄)(HSO₄) (monoclinic, P2₁/n, a = 545.62(6) pm, b = 1075.6(1) pm, c = 1053.1(1) pm, β = 104.58(1)°) at 60 °C. In both hydrogensulfates, Er³⁺ is surrounded by eight oxygen atoms. In Er(HSO₄)₃-I layers of HSO₄^– groups are connected only via hydrogen bridges, while Er(HSO₄)₃-II consists of a threedimensional polyhedra network. In the crystal structure of Er(SO₄)(HSO₄) Er³⁺ is sevenfold coordinated by oxygen atoms, which belong to four SO₄^2–- and three HSO₄^–-tetrahedra, respectively. The anhydrous sulfate, Er₂(SO₄)₃, cannot be prepared from H₂SO₄ solutions but crystallizes from a NaCl-melt. The coordination number of Er³⁺ in Er₂(SO₄)₃ (orthorhombic, Pbcn, a = 1270.9(1) pm, b = 913.01(7) pm, c = 921.67(7) pm) is six. The octahedral coordinationpolyhedra are connected via all vertices to the SO₄^2–-tetrahedra.     

Reaction with SO3 in Ionic Liquids: The Example of K2(S2O7)­(H2SO4)

The ionic liquid 1‐butyl‐3‐methylimidazolium hydrogensulfate, [bmim]HSO₄, turned out to be resistant even to strong oxidizers like SO₃. Thus, it should be a suitable solvent for the preparation of polysulfates at low temperatures. As a proof of principle we here present the synthesis and crystal structure of K₂(S₂O₇)(H₂SO₄), which has been obtained from the reaction of K₂SO₄ and SO₃ in [bmim]HSO₄. In the crystal structure of K₂(S₂O₇)(H₂SO₄) (orthorhombic, Pbca, Z = 8, a = 810.64(2) pm, b = 1047.90(2) pm, c = 2328.86(6) pm, V = 1978.30(8) ų) two crystallographically unique potassium cations are coordinated by a different number of monodentate and bidentate‐chelating disulfate anions as well as by sulfuric acid molecules. The crystal structure consists of alternating layers of [K₂(S₂O₇)] slabs and H₂SO₄ molecules. Hydrogen bonds between hydrogen atoms of sulfuric acid molecules and oxygen atoms of the neighboring disulfate anions are observed.     

Single‐crystal neutron‐diffraction study of 3.4% Zn‐doped (ND4)2[Cu(D2O)6](SO4)2 at 20 K

Doping the perdeuterated ammonium copper Tutton salt (ND₄)₂[Cu(D₂O)₆](SO₄)₂ [perdeuterated diammonium hexa­aqua­copper(II) bis­(sulfate)] with Zn leads to a change in the structure from dimorph A (low density) to dimorph B (high density). This change, which accompanies a switch in the direction of the Jahn–Teller distortion, had previously been observed to occur with substitution of Zn²⁺ at the Cu²⁺ site of between 1.3 (A) and 3.4% (B). In this study, the single‐crystal neutron‐diffraction analysis of (ND₄)₂[(Cu/Zn)(D₂O)₆](SO₄)₂ at 20 K, with 3.4% Zn doping and a deuterium substitution of 85% on the H‐atom sites, reveals that the structure is entirely of type B, with the Cu/Zn site at an inversion centre and with no evidence of disorder or unusual atomic displacement parameters that might occur near a phase transition boundary.     

Reaktionen von [B12H12–n(OH)n]2–, n = 1, 2 mit Säuredichloriden und Kristallstruktur von Cs2[1,2-B12H10(ox)] · CH3OH

Reactions of [B₁₂H_12–n(OH)_n]^2–, n = 1, 2 with Acid Dichlorides and Crystal Structure of Cs₂[1,2-B₁₂H₁₀(ox)] · CH₃OH By treatment of [B₁₂H₁₁(OH)]^2– with organic and inorganic acid dichlorides in acetonitrile the bridged dicluster compounds [B₁₂H₁₁(ox)B₁₂H₁₁)]^4– ( 1 ), [B₁₂H₁₁(p-OOCC₆H₄COO)B₁₂H₁₁]^4– ( 2 ), [B₁₂H₁₁(m-OOCC₆H₄COO)B₁₂H₁₁]^4– ( 3 ), [B₁₂H₁₁(SO₃)B₁₂H₁₁]^4– ( 4 ), [B₁₂H₁₁(SO₄)B₁₂H₁₁]^4– ( 5 ) are obtained in good yields. The dihydroxododecaborates [1,2-B₁₂H₁₀(OH)₂]^2– and [1,7-B₁₂H₁₀(OH)₂]^2– afford clusters with an anellated ring: [1,2-B₁₂H₁₀(ox)]^2– ( 6 ), [1,2-B₁₂H₁₀(SO₄)]^2– ( 7 ) and [1,7-B₁₂H₁₀(OOC(CH₂)₈COO)]^2– ( 8 ). Isomerically pure [1,7-B₁₂H₁₀(OH)₂]^2– ( 9 ) is formed by reaction of (H₃O)₂[B₁₂H₁₂] with ethylene glycol. All new compounds are characterized by vibrational, ¹¹B, ¹³C and ¹H NMR spectra. The crystal structure of Cs₂[1,2-B₁₂H₁₀(ox)] · CH₃OH (monoclinic, space group P 2₁/c, a = 9.616(2), b = 10.817(1), c = 15.875(6) Å, β = 95.84(8)°, Z = 4) reveals a distortion of the B₁₂ icosahedron caused by the anellated six-membered heteroring.     

First Characterization of an Extended Ammonium‐Ammonia Complex [{NH4(NH3)4}+(μ‐NH3)2] in the Crystal Structure of [NH4(NH3)4][Co(C2B9H11)2] · 2 NH3

The compound [NH₄(NH₃)₄][Co(C₂B₉H₁₁)₂] · 2 NH₃ ( 1 ) was prepared by the reaction of Na[Co(C₂B₉H₁₁)₂] with a proton‐charged ion‐exchange resin in liquid ammonia. The ammoniate 1 was characterized by low temperature single‐crystal X‐ray structure analysis. The anionic part of the structure consists of [Co(C₂B₉H₁₁)₂]^‐ complexes, which are connected via C‐H···H‐B dihydrogen bonds. Furthermore, 1 contains an infinite equation/tex2gif-stack-2.gif[{NH₄(NH₃)₄}⁺(μ‐NH₃)₂] cationic chain, which is formed by [NH₄(NH₃)₄]⁺ ions linked by two ammonia molecules. The N‐H···N hydrogen bonds range from 1.92 to 2.71Å (DHA = Donor···Acceptor angles: 136‐176°). Additional N‐H···H‐B dihydrogen bonds are observed (H···H: 2.3‐2.4Å).