Hydrazine Sulfonic Acid, NH3 NH(SO3 ), the Bigger Sibling of Sulfamic Acid.

The reaction of hydrazine hydrate, N2 H4 ⋅ H2 O, and SO3 leads to hydrazine sulfonic acid (Pca21 , a=849.59(4) pm, b=482.18(2) pm, c=832.17(4) pm). Structure elucidation reveals the zwitter-anionic nature of the compound according to NH3 NH(SO3 ). With the barium salt Ba[NH2 NH(SO3 )]2 (H2 O), a first salt of hydrazine sulfonic acid has been prepared (P 1 ‾ $\bar 1$ , a=489.75(5) pm, b=737.52(7) pm, c=1317.4(1) pm, α=88.238(4)°, ß=84.761(4)°, γ=79.701(4)°). The compounds were characterized by vibrational spectroscopy, DFT calculations and thermal analyses.

Triflate's bigger brother: The unprecedented tribrate anion, [Br3 CSO3 ].

The synthesis of the unprecedented [Br3 CSO3 ]- anion starts with the bromination of phenylmethanesulfonate, C6 H5 OSO2 CH3 , with KOBr leading to C6 H5 OSO2 CBr3 . The formation of the [CBr3 ] moiety has been proved, also by an X-ray structure determination of the compound (triclinic, P-1, a=685.9(2), b=698.1(2), c=1190.2(3) pm, α=93.99(1)°, ß=97.42(1)°, γ=94.45(1)°). The ester C6 H5 OSO2 CBr3 can be split under basic conditions. The resulting acid provides access to the yet unknown tribromomethanesulfates ("tribrates"). K[Br3 CSO3 ] ⋅ H2 O, the first tribrate known so far has been characterized comprehensively, including an X-ray structure determination (monoclinic, C2/c, a=2267.1(2), b=1282.25(8), c=2618.2(2) pm, ß=111.266(2)°), vibrational spectroscopy and theoretical calculations. Moreover, the thermal analysis shows that, after loss of the crystal water, the tribrate decomposes between 530 and 630 K.

The Divalent Lanthanoid Triflates Ln(CF3SO3)2(CH3CN) (Ln=Sm, Eu): Structure, Luminescence, and Magnetism.

The reaction of the trivalent lanthanoide triflates Ln(OTf)3 (Ln=Sm, Eu; OTf=CF3SO3 -) with the respective metals in acetonitrile leads to the Ln(II)-triflates Eu(OTf)2(CH3CN) (monoclinic, P21/n, Z=4, a=1053.54(1), b=610.28(5), c=1946.92(2) pm, ß =98.611(4)) and Sm(OTf)2(CH3CN) (monoclinic, P21/n, Z=4, a=1054.41(4), b=612.16(2), c=1952.65(7) pm, ß =98.524(2)). The isotypic strontium compound Sr(OTf)2(CH3CN) (monoclinic, P21/n, Z=4, a=1056.39(5), b=610.05(3), c=1950.1(1) pm, ß =98.900(2)°) has been obtained from SrCO3 and triflic acid. The compounds have been investigated by X-ray diffraction, vibrational spectroscopy, luminescence spectroscopy, cyclic voltammetry, thermal analysis, and magnetic measurements.

Stabilization of Pr4+ in Silicates─High-Pressure Synthesis of PrSi3O8 and Pr2Si7O18.

The reaction between PrO2 and SiO2 was investigated at various pressure points up to 29 GPa in a diamond anvil cell using laser heating and in situ single-crystal structure analysis. The pressure points at 5 and 10 GPa produced Pr2III(Si2O7), whereas Pr4IIISi3O12 and Pr2IV(O2)O3 were obtained at 15 GPa. Pr4IIISi3O12 can be interpreted as a high-pressure modification of the still unknown orthosilicate Pr4III(SiO4)3. PrIVSi3O8 and Pr2IVSi7O18 that contain praseodymium in its rare + IV oxidation state were identified at 29 GPa. After the pressure was released from the reaction chamber, the Pr(IV) silicates could be recovered, indicating that they are metastable at ambient pressure. Density functional theory calculations of the electronic structure corroborate the oxidation state of praseodymium in both PrIVSi3O8 and Pr2IVSi7O18. Both silicates are the first structurally characterized representatives of Pr4+-containing salts with oxoanions. All three silicates contain condensed networks of [SiO6] octahedra which is unprecedented in the rich chemistry of lanthanoid silicates.

The Cyanido-Sulfate Anion [SO3 CN].

The reaction of the pyridine adduct of SO3 and tetra-n-butyl-ammonium cyanide, [N(n Bu)4 ][CN] at room temperature leads to the unprecedented cyanido-sulfate anion [SO3 CN]- stabilized in the salt [N(n Bu)4 ][SO3 CN]. The anion is a pseudo-halogen congener of the well-known fluoro- and chloro-sulfates. The new anion has been studied by vibrational spectroscopy and theoretical calculations.

Trichlates, an Unattended Class of Compounds: Characterization of Cl3 CSO2 Cl, and (H5 O2 )[Cl3 CSO3 ].

Chlorination of CS2 leads to trichloromethanesulfenyl chloride, Cl3 CSCl, in moderate yields. The oxidation of Cl3 CSCl with H2 O2 gives Cl3 CSO2 Cl, the chloride of trichloromethanesulfonic acid. Cl3 CSO2 Cl is the crucial product for the preparation of trichloromethanesulfonates ("trichlates") and has been characterized by IR spectroscopy, differential scanning calorimetry (DSC) and X-ray diffraction measurements (P-1, a=609.99(5) pm, b=727.45(6) pm, c=782.49(7) pm, α=80.644(3)°, ß=85.175(3)°, γ=88.311(3)°. The acid Cl3 CSO3 H can be gained in form of the hydrate (H5 O2 )[Cl3 CSO3 ] in two different modifications (I: monoclinic, P21 /n, Z=8, a=1292.47(7) pm, b=605.89(2) pm, c=2661.1(1) pm, ß=98.708(4)°, V=1672.8(1) Å3 ; II: monoclinic, Cc, Z=4, a=699.80(5) pm, b=1054.72(8) pm, c=1139.88(8) pm, ß=95.303(3)°, V=837.7(1) Å3 . Both modifications have been investigated by IR spectroscopy, thermal analyses and theoretical calculations.

Impact of 1,10-Phenanthroline-Induced Intermediate Valence on the Luminesence of Divalent Europium Halides.

Starting from EuX2 (X = Cl, Br, I), we systematically investigated a variety of divalent europium complexes containing bidentate 1,10-phenanthroline (Phen) ligands. Depending on the Eu/Phen ratio, mono-, di-, and polynuclear complexes are formed, with the latter yielding one-dimensional ∞1[EuBr2(phen)] chains. Seven new divalent europium complexes, [Eu(phen)4(H2O)]Br2·2MeCN, [Eu(phen)4]I2·1.7Tol, [EuBr(phen)3]2Br2·4MeCN, [EuCl2(phen)2]2·2MeCN, [EuBr2(phen)2]2, [EuI2(phen)2]2, and [EuBr2(phen)]x, are presented in this work. All species show remarkable optical properties based on a partial electron transfer from the EuII center to the Phen ligand. The photophysical characterization is further supported by electrochemistry studies in order to describe the intermediate valence of the Eu center.

The Unprecedented [S4 N2 O10 ]2- Anion in the Molecular Gold Complexes [Au2 Br2 (S4 N2 O10 )2 ] and [Au2 Cl2 (S4 N2 O10 )2 ](S2 O5 Cl2 ).

The reaction of hexachlorophosphazene, P3 N3 Cl6 , with SO3 and the gold halides AuCl3 and AuBr3 , respectively, leads to the new cyclic anionic tetramer, [S4 N2 O10 ]2- , which is coordinated to Au3+ in the dimeric complexes [Au2 X2 (S4 N2 O10 )2 ] (X=Cl, Br). The [S4 N2 O10 ]2- anion can be seen as the condensation product of two sulfate anions, [SO4 ]2- , and two amidosulfate anions, [NH2 SO3 ]- .

Selenous Acid in an Aromatic Framework: Insights Into a Temperature-Sensitive Internal Redox System from the Solid State.

We report on a new compound composed of a phenanthroline network in which emerging channels are alternately occupied by selenous acid (H2SeO3) and dioxane molecules. The material undergoes a variety of structural changes due to both its redox activity as well as its thermal decomposition. We investigate an internal redox system of the incorporated selenous acid and the aldehyde groups of the phenanthroline framework. The reduction process of the selenium species was further elucidated by cyclic voltammetry, while the oxidation process was also monitored by 1H NMR spectra. The thermal behavior reveals that the material can undergo a reversible, topotactic transition due to dioxane and water (de)intercalation.

Ammonium Pertechnetate in Mixtures of Trifluoromethanesulfonic Acid and Trifluoromethanesulfonic Anhydride.

Ammonium pertechnetate reacts in mixtures of trifluoromethanesulfonic anhydride and trifluoromethanesulfonic acid under final formation of ammonium pentakis(trifluoromethanesulfonato)oxidotechnetate(V), (NH4 )2 [TcO(OTf)5 ]. The reaction proceeds only at exact concentrations and under the exclusion of air and moisture via pertechnetyl trifluoromethanesulfonate, [TcO3 (OTf)], and intermediate TcVI species. 99 Tc nuclear magnetic resonance (NMR) has been used to study the TcVII compound and electron paramagnetic resonance (EPR), 99 Tc NMR and X-ray absorption near-edge structure (XANES) experiments indicate the presence of the reduced technetium species. In moist air, (NH4 )2 [TcO(OTf)5 ] slowly hydrolyses under formation of the tetrameric oxidotechnetate(V) (NH4 )4 [{TcO(TcO4 )4 }4 ] ⋅10 H2 O. Single-crystal X-ray crystallography was used to determine the solid-state structures. Additionally, UV/Vis absorption and IR spectra as well as quantum chemical calculations confirm the identity of the species.

S6 N2 O15 -A Nitrogen-Poor Sulfur Nitride Oxide, and the Anhydride of Nitrido-tris-Sulfuric Acid.

The reaction of hexachlorophosphazene, P3 N3 Cl6 , with SO3 leads to the new sulfur nitride oxide S6 N2 O15 . The compound displays an extraordinarily low nitrogen content and exhibits a bicyclic cage structure according to the formulation N{S(O)2 O(O)2 S}3 N, with both nitrogen atoms in trigonal planar coordination of sulfur atoms. Interestingly, the new nitride oxide can be also seen as the anhydride of nitrido-tris-sulfuric acid, N(SO3 H)3 .

Towards Polysulfuric Acids: The Hydrogentrisulfate Anion [HS3 O10 ]- in A[HS3 O10 ] (A=Na, K, Rb).

The reaction of Na2 SO4 and K2 SO4 with fuming sulfuric acid (65 % SO3 ) yielded colorless extremely sensitive crystals of Na[HS3 O10 ] (monoclinic; P21 /n (No. 14); Z=4; a=707.36(2), b=1378.56(4), c=848.10(3) pm; ß=94.817(1)°; V=824.09(4)⋅106  pm3 ) and K[HS3 O10 ] (orthorhombic; Pccn (No. 56); Z=4; a=1057.16(3), b=807.81(2), c=897.57(2) pm; V=766.51(3)⋅106  pm3 ). The analogous rubidium compound Rb[HS3 O10 ] (orthorhombic; Pnma (No. 62); Z=4; a=891.43(3), b=1095.34(4), c=839.37(3) pm; V=819.58(5)⋅106  pm3 ) originates from the reaction of Rb2 CO3 and SO3 . All of the different structures contain the hitherto unknown anion [HS3 O10 ]- and are stamped by strong hydrogen bonds linking the anions either to dimers or chains. Theoretical investigations by DFT methods give further insight in the structural characteristics of [HS3 O10 ]- . The preparation of the [HS3 O10 ]- anion can be seen as an important milestone on our way to the still elusive polysulfuric acids.

Palladium(IV) in an Oxoanionic Environment: The XeF2 Assisted Synthesis of [Pd(S2 O7 )3 ](2.).

For the first time tetravalent palladium is detected, coordinated exclusively by simple oxoanions. Stabilization was achieved by formation of the [Pd(S2 O7 )3 ](2-) complex in which three chelating disulfate groups surround the metal atom. The salt K2 [Pd(S2 O7 )3 ] could only be obtained if the reaction of K2 [PdCl6 ] and neat SO3 was performed in the presence of XeF2 .

Polysulfates [Sn O3n+1 ]2- : With the [S6 O19 ]2- Anion, has the End been Reached?

The S6 O192- ion was obtained both as rubidium and ammonium salt from the reaction of the respective sulfate with SO3 . It is the largest polysulfate ion known to date and exhibits a chain of six vertex-connected [SO4 ] tetrahedra. The unique compound was comprehensively characterized and the bonding within the anion was elucidated by theoretical investigations.

Oxoanionic noble metal compounds from fuming nitric acid: the palladium examples Pd(NO3)2 and Pd(CH3SO3)2.

The oxidation of elemental palladium at 100 °C in a mixture of fuming nitric acid and a pyridine-SO3 complex leads to the anhydrous nitrate Pd(NO3)2 (monoclinic, P2(1)/n, Z=2, a=469.12(3) pm, b=593.89(3) pm, c=805.72(4) pm, ß=105.989(3)°, V=215.79(2) Å(3)). The Pd(2+) ions are in square-planar coordination with four monodentate nitrate groups which are connected to further palladium atoms, leading to a layer structure. The reaction of elemental palladium with a mixture of fuming nitric acid and methanesulfonic acid at 120 °C leads to single crystals of Pd(CH3SO3)2 (monoclinic, P2(1)/n, Z=2, a=480.44(1) pm, b=1085.53(3) pm, c=739.78(2) pm, ß=102.785(1)°, V=376.254(17) Å(3)). Also in this structure the Pd(2+) ions are in square-planar coordination with four monodentate anions; however, the connection to adjacent palladium atoms leads to a chain-type structure. The thermal decomposition of the compounds has been investigated by means of DSC/TG measurements. Furthermore, IR and Raman spectra have been recorded, and an assignment of the observed vibrational frequencies has been carried out based on theoretical investigations.

A Highly Triflated Rare-Earth Ion in [Eu(O3SCF3)8](5-).

The reaction of Eu2O3 with fuming nitric acid, trifluormethanesulfonic acid, and its anhydride in torch-sealed glass ampoules at 120 °C gave the europium compound (NO)5[Eu(O3SCF3)8] (orthorhombic, Fddd, Z = 16, a = 1932.69(4), b = 2878.44(7), c = 2955.12(7) pm, V = 16439.7(7) Å(3)). The compound exhibits the [Eu(O3SCF3)8](5-) anion showing for the first time a lanthanide ion that is exclusively coordinated by eight triflate anions. The anion has been further investigated by DFT calculations, which also allowed clear assignment of the vibrational spectra. Moreover, magnetochemical and luminescence measurements gave additional insight into the properties of this complex. The luminescence spectra revealed that the Eu(3+) ions are in a pseudo D4d symmetric environment.

Chelating and Linking S4O13(2-) Anions: Synthesis and Characterization of the Bis-(tetrasulfato) Palladates M2[Pd(S4O13)2] (M = NH4, Rb, NO) and the Sodium Palladium Tetrasulfate Na2Pd(S4O13)2.

The reaction of SO3 with either the palladium chlorides M2PdCl6 (M = Rb, NH4) or the nitrato-palladate (NO)2[Pd(NO3)4] at elevated temperature led to yellow single crystals of the complex palladates M2[Pd(S4O13)2] (M = NH4: triclinic, P1̅, a = 7.3882(3) Å, b = 8.5223(3) Å, c = 9.2712(4) Å, α = 71.945(2)°, ß = 88.910(2)°, γ = 72.603(2)°, V = 527.88(4) Å3; M = NO: triclinic, P1̅, a = 7.2881(3) Å, b = 8.9125(2) Å, c = 8.9220(4) Å, α = 75.546(2)°, ß = 89.151(2)°, γ = 69.516(2)°, V = 524.02(4) Å3; M = Rb: triclinic, P1̅, a = 7.4468(4) Å, b = 8.5066(4) Å, c = 9.2477(4) Å, α = 72.321(2)°, ß = 88.512(2)°, γ = 72.128(2)°, V = 529.75(4) Å3). In the isotypic compounds, the Pd atom is in square planar oxygen coordination, achieved by two bidentate-chelating tetrasulfate anions. The reaction of Na2PdCl6 with neat SO3 afforded yellow crystals of Na2Pd(S4O13)2 (monoclinic, P21/c, a = 6.9953(4) Å, b = 15.9420(9) Å, c = 9.2299(5) Å, ß = 100.235(2)°, V = 1012.45(1) Å3). The structure exhibits no palladate complexes but an anionic two-dimensional network, according to ∞2[Pd(S4O13)(4/2)]2­. The latter shows the tetrasulfate anions acting as bidentate-bridging ligands. The tetrasulfato-palladates were studied in more detail by means of thermal analyses and infrared (IR) spectroscopy. The observed IR bands were assigned according to quantum chemical calculations performed on the anion [Pd(S4O13)2]2­.

Effects of multivalent histamine supported on gold nanoparticles: activation of histamine receptors by derivatized histamine at subnanomolar concentrations.

Colloidal gold nanoparticles with a functionalized ligand shell were synthesized and used as new histamine receptor agonists. Mercaptoundecanoic acid moieties were attached to the surface of the nanoparticles and derivatized with native histamine. The multivalent presentation of the immobilized ligands carried by the gold nanoparticles resulted in extremely low activation concentrations for histamine receptors on rat colonic epithelium. As a functional read-out system, chloride secretion resulting from stimulation of neuronal and epithelial histamine H1 and H2 receptors was measured in Ussing chamber experiments. These responses were strictly attributed to the histamine entities as histamine-free particles Au-MUDOLS or the monovalent ligand AcS-MUDA-HA proved to be ineffective. The vitality of the tissues used was not impaired by the nanoparticles.

Ferromagnetic ordering in the layer-structured Pd(HS(2)O(7))(2).

The reaction of (NO2 )(CF3 SO3 ) and elemental palladium in oleum (65 % SO3 ) leads to violet single crystals of Pd(HS2 O7 )2 (monoclinic, P21 /c, Z=2, a=927.80(9), b=682.58(7), c=920.84(9) pm, ß=117.756(2)°, wR2 =0.0439). In the crystal structure, the Pd(2+) ions show an uncommon octahedral coordination of six oxygen atoms belonging to six HS2 O7 (-) ions. The linkage of [PdO6 ] octahedra and the hydrogendisulfate anions leads to a layer structure, and the layers are held together by hydrogen bonds. The unusual coordination of the Pd(2+) ions results in an electronic d(8) high-spin configuration, which leads to the paramagnetic behavior of the compound. Moreover, at low temperature, a ferromagnetic ordering was observed with a Curie temperature of 8 K.

Oxidizing elemental platinum with oleum under harsh conditions: the unique tris(disulfato)platinate(IV) [Pt(S2O7)3]2- anion.

For the first time, direct oxidation of elemental platinum by a mineral acid to its tetravalent state was observed in course of the reaction of platinum with oleum (65 % SO3) in the presence of barium carbonate. The reaction has been carried out in torch-sealed glass ampoules at 160 °C and gave yellow single crystals of Ba[Pt(S2O7)3](H2SO4)0.5(H2S O7)0.5 (triclinic, P1, Z=2, a=992.05(2), b=1069.07(3), c=1114.22(3) pm, α=69.49(7), ß=72.96(2), γ=72.93(1)°, V=1033.95(5) Å(3)). The structure of Ba[Pt(S2O7)3](H2SO4)0.5(H2S2O7)0.5 exhibits the unique tris-(disulfato)-platinate anion [Pt(S2O7)3](2-) with three chelating disulfate groups coordinated to the platinum atom. Charge balance is achieved by the Ba(2+) ions, which are coordinated by (S2O7)(2-) groups from the platinate complex and by disordered sulfuric acids and disulfuric acid molecules. Thermal decomposition of the bulk material revealed elemental platinum and barium sulfate as decomposition residual.