Chemical and electrochemical behavior of metallic technetium in acidic media

The chemical and electrochemical properties of technetium metal were studied in 1–6 M HX and in 1 M NaX (pH 1 and 2.5), X = Cl, NO₃. The chemical dissolution rates of Tc metal were higher in HNO₃ than in HCl (i.e. 8.63 × 10^?5 mol cm^?2 h^?1 in 6 M HNO₃ versus 2.05 × 10^?9 mol cm^?2 h^?1 in 6 M HCl). The electrochemical dissolution rates in HNO₃ and HCl were similar and mainly depended on the electrochemical potential and the acid concentration. The optimum dissolution of Tc metal was obtained in 1 M HNO₃ at 1 V/AgAgCl (1.70 × 10^?3 mol cm^?2 h^?1). The dissolution potentials of Tc metal in nitric acid were in the range of 0.596–0.832 V/AgAgCl. Comparison of Tc behavior with Mo and Ru indicated that in HNO₃, the dissolution rate followed the order: Mo > Tc > Ru, and for dissolution potential the order: E _diss(Ru) > E _diss(Tc) > E _diss(Mo). The corrosion products of Tc metal were analyzed in HCl solution by UV–Visible spectroscopy and showed the presence of TcO₄ ^?. The surface of the electrode was characterized by microscopic techniques; it indicated that Tc metal preferentially corroded at the scratches formed during the polishing and no oxide layer was observed.     

Bis(phthalocyaninato(2–)rhenium(II)): Synthesis,Properties, and Crystal Structure

Blue, paramagnetic bis(phthalocyaninato(2–)rhenium(II)) (μ_eff = 0,88 μ_B, per Re, at 300 K) is prepared by thermal decomposition of trans-bis(triphenylphosphine)phthalocyaninato(2–)rhenium(II), in boiling triphenylphosphine. It crystallizes in the triclinic space group P 1 with cell parameters as follows: a = 7.799(3) Å, b = 12.563(7) Å, c = 12.69(1) Å, α = 89.97(5)°, β = 94.14(5)°, γ = 106.39(4)°; Z = 1. Two cofacial phthalocyaninates are bonded together by a Re–Re bond with a Re–Re distance of 2.285(2) Å. The Re atoms are located distinctly outside the centre of the (N_iso)₄ planes by 0.426(3) Å. The Re–N_iso distance varies from 1.99(1) to 2.04(1) Å (average 2.02 Å). The pc^2– ligands are in an eclipsed conformation and concavely distorted. In the UV-VIS-NIR spectrum the B region is split into two bands of comparable intensity due to strong excitonic coupling. The Re–Re stretching vibration at 240 cm^–1 is selectively enhanced in the resonance Raman spectrum (λ_exc = 488 nm).     

Syntheses and Characterization of Organoimido Complexes of Niobium(V); Potential CVD Precursors

New niobium imido complexes (RN)Nb(NEt₂)₃ (R = Prⁿ, Prⁱ and Bu^t), potential precursors to grow niobium containing thin films by chemical vapor deposition (CVD), were prepared by reacting the corresponding (RN)NbCl₃py₂ complexes (R = Prⁿ, Prⁱ and Bu^t; py = pyridine) with LiNEt₂ in hydrocarbon solvents. The structures of (RN)NbCl₃py₂ (R = Prⁱ and Bu^t), determined by X-ray crystallography, are mononuclear with distorted octahedral geometries, For each complex, three chloride ligands are cis to the imido ligand and occupy meridional positions. One of two py ligands is cis to and the other is trans to the imido ligand. For (PrⁱN)NbCl₃py₂, the Nb=NPrⁱ bond distance (Å) is 1.733(3) and the ∠Nb=N-Prⁱ angle (°) is 178.0(3). Crystal data: monoclinic, space group P2₁/n, a = 8.805(2), b = 14.930(4), c = 13, 407(3) Å, β = 93.37(2)°, V = 1759.5(7) ų, Z = 4, D_c = 1.565 g cm³. For (Bu^tN)NbCl₃py₂, the Nb=NBu^t bond distance (Å) is 1.734(4) and the ∠Nb=N-Bu^l angle (°) is 174.8(4). Crystal data: monoclinic, space group P2₁/c, a = 9.609(1), b = 13.591(6), c = 14.615(2) Å, β = 90.05(1)°, V = 1908.5(9) ų, Z = 4, D_c = 1.492 g cm^?3.     

Studies on organometallic compounds with hetero multiple bridges : V. Crystal and molecular structure of the parent rhenium complex Re2Br2(CO)6(THF)2 and substituted products of tricarbonylrhenium(I) derived from it

Reactions of the tetrahydrofuran adduct Re₂Br₂(CO)₆(THF)₂ with some phosphorous- and nitrogen-containing donors under mild conditions are reported, which led to the formation of substituted products of tricarbonylrhenium(I). Bromide abstraction from the THF adduct by secondary amines and CS₂ produced the dithiocarbamato derivatives Re(S₂CNR₂)(CO)₃(HNR₂) whose behaviour in solution with CO was also investigated. Mass spectral data for some of the substituted products have been measured. The title compound crystallizes in the space group P2₁/n with cell constants a = 8.661(2), b = 11.251(3), c = 11.424(3) Å and β = 110.36(2)°, U = 1043.67 ų and D_calc = 2.686 g cm^?3, Z = 2. The molecule consists of a planar Re₂Br₂ moiety, as demanded by symmetry. The two THF groups are on opposite sides of this plane and the three CO groups around each rhenium atom are arranged in a fac arrangement. The unique ReBr distances are 2.642(5) and 2.644(4)Å, while the ReO distance is 2.129(31) Å. The ReBrRe and BrReBr angles are 97.3(2) and 82.7(1)°, respectively. The Re?Re nonbonding distance is 3.967(3) Å. The THF ligands consist of a nearly planar C₄ fragment (maximum deviation from planarity 0.06 Å), while the oxygen is 0.348 Å out of that plane, the angle defined by the C₄ plane and the COC fragment of the THF ligand being 24.99°. Final values of the discrepancy indices are R(F) = 0.074 and R_w(F) = 0.095.     

Effect of EDTA on the diffusion behavior of 99TcO4 − and ReO4 − in GMZ bentonite

Polyaminopolycarboxylate EDTA with powerful metal-binding property, which often presents in low and intermediate-level waste, can enhance the radionuclide migration. The effect of EDTA on the diffusion behavior of ⁹⁹TcO₄ ^? and ReO₄ ^? in Gaomiaozi (GMZ) bentonite was investigated by using through-diffusion method. For ⁹⁹TcO₄ ^? in present of EDTA, the D _e values was (1.2 ± 0.1) × 10^?11 m²/s, which was 4 times higher than that in absent of EDTA. It can be explained that the complexation between ⁹⁹TcO₄ ^? and EDTA might be formed. By contrast, the D _e values of ReO₄ ^? remained unchanged in present or absent of EDTA, indicating that ReO₄ ^? could not complex with EDTA. However, the diffusion of ReO₄ ^? could be increased in present of EDTA, the D _a value was found to be increased from 1.8 × 10^?10 to 5.4 × 10^?10 m²/s. It demonstrated that ReO₄ ^? need more drastic conditions to form the Re(VII)–EDTA complexes than those used for ⁹⁹TcO₄ ^?. For both ReO₄ ^? and ⁹⁹TcO₄ ^?, the rock capacity factor α is less than the total porosity ε _tot, indicating that they has little retention/sorption on the surface of bentonite.     

Reduction of copper (II) chloride by molybdenum and rhenium biscyclopentadienyl hydrides. Investigation of the crystal and molecular structure of [(η5-C5H5)2Re]+[CuCl2]−

The reduction of copper (II) chloride by molybdenum and rhenium biscyclopentadienyl hydrides upon their interaction in donor-type solvents has been studied by NMR, X-ray diffraction, and magnetic methods. It is established that the ionic complex [(η⁵-C₅H₅)₂Re]⁺[CuCl₂]^? forms ortho rhombic crystals with a - 13.696(2) Å, b = 7.317(1) Å, c = 5.969(1) Å, space group Pm2₁n, Z = 2. The cyclopentadienyl rings make a bent-sandwich with an angle between the ring centres and Re atom of 150.1°; the ClCuCl angle being 174.8° and the ReCu minimum distance 4.346(29) Å. The solution of [(η⁵-C⁵H₅)²Re]⁺ [CuCl₂]^? seems to activate the CH bond of the C₅H₅ rings, which results in the addition of the [(C₅H₅)(C₅H₄)ReH]⁺ hydride ion.     

Effects of ionic strength and humic acid on 99TcO4 ? sorption and diffusion in Beishan granite

In terms of pre-safety assessment of a potential site for high-level radioactive wastes disposal in China, the geochemical behavior of key radionuclides which tend to be released from the repository must be thoroughly investigated. ⁹⁹Tc is a long-lived fission product with appreciable productivity in nuclear fuel, and Tc (+7) has unlimited solubility in near-field geochemical environments. In this study, the effects of ionic strength and humic acid on ⁹⁹TcO₄ ^? sorption and diffusion in Beishan granite were investigated with through-diffusion and batch sorption experiments. Results indicated that the effective diffusion coefficients (D _e) of ⁹⁹TcO₄ ^? in Beishan granite varied from 1.07?×?10^?12 to 1.28?×?10^?12?m²/s without change with ionic strength, while the distribution coefficients (K _d) negatively correlated with ionic strength of the rock/water system. This study also indicates that there is no evident influence of humic acid concentration on the diffusion behavior of ⁹⁹TcO₄ ^? in Beishan granite, due to the limited interaction between humic acid and ⁹⁹TcO₄ ^?.     

Crystal and molecular structure of tricyclopentadienyltetrahydrofuranuranium(III), (η5-C5H5)3U·OC4H8

Tricyclopentadienyltetrahydrofuranuranium(III), (η⁵-C₅H₅)₃U·OC₄H₈, crystallizes in the centrosymmetric monoclinic space group P2₁/n with a 8.248(3), b 24.322(17), c 8.357(4) Å, β 101.29(5)°, V 1644.0 ų and ρ(calc) 2.04 g cm^?1 for Z = 4 and mol.wt. 595.0. Diffraction data (Mo-K_α, 2θ(max) 45°) were collected on an Enraf-Nonius CAD4 diffractometer and the structure was refined to R_w(F) 4.7% for those 1530 reflections having I > 2σ(I). The molecule consists of a distorted tetrahedral arrangement of THF and (η⁵-C₅H₅) ligands with CpUCp angles in the range 110.4–122.4° and CpUO angles between 90.2 and 106.0°. Individual uranium-carbon distances range from 2.76(2) to 2.82(2) Å and average 2.79[1] Å. The uranium-oxygen distance of 2.551(10) Å suggests a 10-coordinate U³⁺ radius of 1.20 Å in this class of compounds.     

Crystal structure of hexakis(thiourea)-bis((μ-perchlorato-O,O’)-(perchlorato-O)-bismuth) diperchlorate

The complex[Bi₂(Tu)₆(ClO₄)₄](ClO₄)₂ (I) (Tu is thiourea) was synthesized and studied by X-ray diffraction. The crystallographic data of I are: a = 14.205(1) Å, b = 13.083(1) Å, c = 22.078(2) Å, β = 96.182(1)°, V = 4079.1(7) ų, space group C2/c, Z = 4. The molecule is located on a twofold axis and consists of the binuclear cation [Bi₂(Tu)₆(ClO₄)₄]²⁺ and two outer-sphere anions Cl ₄ ^? . The Bi-S bond lengths are 2.61–2.62 Å. For each terminal and bridging ClO ₄ ^? ion, one Bi-O distance varies from 2.744 to 3.048 3.269 structure contains a hydrogen bond network involving all hydrogen atoms. The IR and Raman spectroscopy data confirm the thiourea coordination by the sulfur atom.     

Separation of no-carrier-added 99mTcO4 − from 99Mo–99mTc equilibrium mixture by PEG based aqueous biphasic separation technique using sodium/potassium salts of citric and tartaric acid

Extraction and separation of no-carrier-added (nca) ^99mTcO₄ ^? from ⁹⁹Mo–^99mTc equilibrium mixture was carried out by environmentally benign polyethylene glycol based liquid–liquid aqueous biphasic systems (ABS) consisting various inorganic salts. Among the various inorganic salt trisodium citrate and potassium sodium tartrate showed the suitable salt rich phase for the best separation in this report. The concentration variation of salt rich phase, temperature and PEG phase also exhaustively studied in paper for the achievement of high separation factor. At 40 °C temperature in 50 % (w/v) PEG-4000-2M Na₃citrate showed the highest separation factor (S _Tc/Mo) 1.2 × 10⁷.     

ReV‐Phthalocyaninate und ReV‐Tetraphenylporphyrinate mit Oxo‐Liganden: Synthese,Eigenschaften und Kristallstruktur

Re^V‐Phthalocyaninates and Re^V‐Tetraphenylporphyrinates: Synthesis, Properties, and Crystal Structure Hexa‐coordinated Re^V phthalocyaninates (pc) and Re^V tetraphenylporphyrinates (tpp) of the type [Re(O)(X)p] (p: pc, tpp) with X = OCH₃, ReO₄, Cl/pc, F/pc, OH/tpp, [{Re(O)p}₂(μ‐O)] and (cat)^trans[Re(O)₂p] (cat: ⁿBu₄N, Et₄N/tpp) have been isolated and characterised by their UV‐Vis‐NIR, IR and resonance Raman (RR) spectra. In the RR spectra, the intensity of the (Re=O) and (Re–X) stretching vibrations (ν(Re=O/–X)) in [Re(O)(X)p] and [{Re(O)p}₂(μ‐O)] is selectively enhanced with excitation in coincidence with O → Re–CT between ca 19000 and 22000 cm^–1. In accordance to selection rules, data of ν(Re=O/–X) compare well with those of the complementary IR spectra. Because of the trans influence ν(Re=O) depends on the axial ligand X, ranging from 940 to 1010 cm^–1. The crystallographic characterization of [Re(O)(ReO₄)tpp] · CHCl₃ ( 1 ), [{Re(O)tpp}₂(μ‐O)] · py ( 2 ), (ⁿBu₄N)^trans[Re(O)₂tpp] ( 3 ), and (Et₄N)^trans[Re(O)₂tpp] · 2 H₂O ( 4 ) is described. The tpp centered Re atom is in a distorted octahedron of four N atoms of the porphyrinate and two axial O atoms in a mutual trans position. Average Re–N distances are 2.062 Å in 1 , 2.086 Å in 2 , 2.089 Å in 3 , and 2.082/2.086 Å in 4 . The Re–O distance of the terminal rhenyl group varies from 1.64(1) Å ( 1 ), 1.73(1)/1.70(1) Å ( 2 ) to 1.80(1) Å ( 4 ), that of the monodentate rhenate(VII) from 1.70(1) to 1.75(1) Å. The Re–O distances in the bridge of the linear O=Re–O–Re=O skeleton in 2 are 1.95(1)/1.89(1) Å. In 1 , with a bent O=Re–O^ ReO₃ moiety (∢(Re–O^ReO₃) = 143(1)°) and a mostly ionic coordinated rhenate(VII), these distances differ significantly (2.20(1) Å vs 1.75(1) Å). The porphyrinate in 1 is saucer‐shaped with a distal rhenate(VII), and the tpp centered Re atom is displaced by 0.31 Å out of the (N)₄ plane towards the rhenyl‐O atom. The distorted porphyrinates in 2 are rotated by 30.4(4)°, and the Re atoms are 0.1 Å out of their (N)₄ planes towards the terminal O atoms. In 3 and 4 the porphyrinates are almost planar with the Re atom in their centre.     

Microwave spectrum of 1,2,4-trifluorobenzene

The microwave spectrum of 1,2,4-trifluorobenzene has been observed in the range 12.5–18.0 GHz and 21.5–25.3 GHz at dry-ice temperature and assigned up to angular momentum state J = 39. The ground state rotational constants and the five quartic centrifugal distortion constants thus obtained are (in MHz): à = 3084.0037 ± 0.0108, B? = 1278.3614 ± 0.0062, C? = 903.6989 ± 0.0108, d_j = ( ?4.599 ± 0.621) · 10^?4, d_jk = (5.9757 ± 1.1586) · 10^?3, d_k = (11.4923 ± 2.0886) · 10^?3, d_wj = (4.0 ± 1.0) · 10^?7, d_wk=(?5.8± 1.1) · 10^?6.The small value of Δ = 0.029 (amu Ų) shows that the molecule is planar and an r₀ - structure using a regular hexagonal benzene ring with the bond lengths C-C = 1.397 Å, C-H = 1.084 Å and C-F = 1.312 Å, reproduces the rotational constants.     

Synthesis and x-ray crystal structure of OsBr2(CNBut)4·2CH2Cl2

Reaction of (NH₄)₂OsBr₆ with excess Na/Hg in THF in the presence of excess ^tBuNC yields trans-OsBr₂(CNBu^t)₄ in high yield. The bis-dichloromethane solvate crystallises from CH₂Cl₂ solutions and its X-ray crystal structure has been determined. Crystal data: C₂₂H₄₀Br₂Cl₄N₄Os, M = 852.40, monoclinic, space group P2₁/c, a = 9.702(3) Å, b = 10.143(5) Å, c = 18.497(5) Å, β = 104.28(3)°, U = 1764(1) ų, Z = 2 for D_c = 1.60 gcm^?3. λ(MoK_α) = 0.71069 Å (graphite monochromator), μ(MoK_α) = 65.44 cm^?1, final R = 0.044, R_w = 0.056 from 1105 observed reflections (1777 measured).     

Pyrolytic production of Se (3P) from carbon diselenide. II. Rate of CSe2 decay

Pyrolytic decay of carbon diselenide was monitored by ultraviolet absorption spectroscopy in reflected shock waves in the temperature range of 1600–2600°K. The temperature dependence of the absorption coefficient of CSe₂ at 2308 Å was determined and was used to provide kinetic information along with a deconvolution procedure which accounted for and removed systematic distortions of the fast time-resolved absorbance profile. For temperatures of 1600–2600°K and argon densities of 1.5–7.0 × 10^?5 mol/cm³ dilute (1.0–9.0 × 10^?9 mol/cm³) CSe₂ pyrolyzed with measured first-order decay rates in the range of log₁₀ k₁ (sec^?1) = 3.0?5.7; at midrange (2100°K and 4.3 × 10^?5 mol/cm³ in Ar) k₁ ≈ 3 × 10⁴ sec^?1. The decay probably occurs via a unimolecular low-pressure process, first order in both CSe₂ and Ar, for which k₂ ± 10⁹ cm³/mol·sec at 2100°K. The deconvoluted data yield Arrhenius activation energies of 53.2 kcal/mol under second-order treatment, but the activation energy is less reliable than the general magnitude of the rate constant. A comparison of CSe₂ with other molecules which are isoelectronic in their valence shells (CO₂, CS₂, OCS, and N₂O) is made.     

A new approach to electron diffraction analysis of symmetric triatomic molecules with large-amplitude bending motion: The equilibrium geometry,force field and vibrational frequencies of BaI2 as determined by electron diffraction

Diffraction data on BaI₂, analyzed by a new approach, indicate an anharmonic potential with a barrier of 71(12) cm^?1 at a linear geometry. The structural and vibrational parameters were found to be r_e^h(Ba-I_o) = 3.150(7)Å, ∠_eIBaI = 148.0(9) °, f_q = 0.69(8) mdyn/Å,f_qq= 0.14(6) mdyn/Å, k₂ = ?0.0075(15) mdyn/Å, k₄ = 0.0025(9) mdyn/ų, v₁ = 106(12) cm^?1 and v₃ = 145(21) cm^?1. The bending frequency v₂ is predicted to be near 16 cm^?1.     

Synthesis,structure, and thermal expansion of sodium zirconium arsenate phosphates

Sodium zirconium arsenate phosphates NaZr₂(AsO₄) _x (PO₄)_3?x were synthesized by precipitation technique and studied by X-ray diffraction and IR spectroscopy. In the series of NaZr₂(AsO₄) _x (PO₄)_3?x , continuous substitution solid solutions are formed (0 ≤ x ≤ 3) with the mineral kosnarite structure. The crystal structure of NaZr₂(AsO₄)_1.5(PO₄)_1.5 was refined by full-profile analysis: space group R \(\bar 3\) c, a = 8.9600(4)Å, c = 22.9770(9) Å, V = 1597.5(1) ų, R _wp = 4.55. The thermal expansion of the arsenate-phosphate NaZr₂(AsO₄)_1.5(PO₄)_1.5 and the arsenate NaZr₂(AsO₄)₃ was studied by thermal X-ray diffraction in the temperature range of 20–800°C. The average linear thermal expansion coefficients (α_av = 2.45 × 10^?6 and 3.91 × 10^?6 K^?1, respectively) indicate that these salts are medium expansion compounds.     

Synthesis and Crystal Structure of (PCl4)[Re2Cl9]

The reaction between PCl₃ and ReCl₅ yielded at 200 °C the ionic tetrachlorophosphonium dirhenium nonachloride, (PCl₄)[Re₂Cl₉]. Single crystal X-ray diffraction analysis revealed a monoclinic unit cell: a = 8.616(3) Å, b = 10.449(4) Å, c = 9.397(3) Å, β = 99.72(3)°, V = 833.9(5) ų, Z = 2, sp. gr. P2₁/m, wR₂ = 0.1083 and R₁ = 0.0527. The ionic compound is built from tetrahedra PCl₄⁺ and face-sharing bioctahedra Re₂Cl₉^–. The Re–Re distance, 2.724 Å, indicates the presence of direct Re-Re interaction.     

Metal solid solutions obtained by thermolysis of Pt and Re salts. Crystal structure of [Pt(NH3)4](ReO4)2

A complex salt of tetraammineplatinum(II) perrhenate [Pt(NH₃)₄](ReO₄)₂ has been synthesized. Crystal data: a = 5.1847(6) Å, b = 7.7397(8) Å, c = 7.9540(9) Å, α = 69.531(3)°, β = 79.656(3)°, γ = 77.649(3)°, V = 290,19(6) ų, space group $P\bar 1$ , Z = 1, d _x = 4.370 g/cm³. The products of decomposition of [Pt(NH₃)₄](ReO₄)₂ in a hydrogen atmosphere were investigated using X-ray phase analysis. In definite temperature modes, these are Pt_0.33Re_0.67 solid solutions based on Re with hcp cell parameters a = 2.76 Å, c = 4.42 Å. The products of thermolysis obtained from other precursor complex salts containing both Pt and Re were investigated. Thus Pt_0.75Re_0.25 solid solution with a = 3.905(3) Å was obtained from (NH₄)₂[ReCl₆]_0.25[PtCl₆]_0.75.     

Crystal structure and thermodynamic stability of an acetone solvate of bis(trifluoroacetylacetonato)copper(II)

A solvate [Cu(CF₃COCHCOCH₃)₂(CH₃COCH₃)] has been synthesized and characterized for the first time. According to X-ray structural data (diffractometer X8 APEX BRUKER, radiation MoK _α, T = 150 K), it crystallizes in the monoclinic crystal system, space group P2₁/c, a = 8.9940(4) Å, b = 22.3966(11) Å, c = 8.1884(3) Å, β = 92.705(2)°, V = 1647.59(12) ų, Z = 4, d _calc = 1.725 g/cm³, final R = 0.0272. The structure is molecular. In the equatorial plane the atom Cu(II) is surrounded with four oxygen atoms of two chelating ligands (CF₃COCHCOCH₃)^?; Cu-O distances 1.927–1.937 Å, O-Cu-O angles 86.18–93.30° and 170.18–175.67°. Square coordination of Cu is complemented to the square-pyramidal one by the oxygen atom of an acetone molecule behaving as an axial ligand; Cu-O_acetone 2.342 Å, O-Cu-O_acetone 89.66–100.11°. In the studied compound disorder of one of the chelate ligands implies the co-existance of the molecules in the cis- and trans-configuration in the crystal under ratio 54.6:45.4. In air the solvate rapidly degrades losing acetone, while in a sealed vessel melts around 313 K. Temperature dependence of equilibrium vapor pressure of acetone over the complex was measured with the static spoon gauge technique, thermodynamic characteristics of its dissociation process being derived: [Cu(CF₃COCHCOCH₃)₂(CH₃COCH₃)]_s = [Cu(CF₃COCHCOCH₃)₂]_s + CH₃COCH_3g, ΔH _av ⁰ = 49.6(3) kJ/mol, ΔS _av ⁰ = 152(1) J/(mol K), ΔG _av ⁰ = 4.30(2) kJ/mol.     

2-Hydroxy-4-methylbenzenesulfonic acid dihydrate: Crystal structure, vibrational spectra, proton conductivity, and thermal stability

The crystal and molecular structure of 2-hydroxy4-methylbenzenesulfonic acid dihydrate C₆H₃(CH₃)(OHSO^? ₃ H₅O₂ ⁺ (I) was studied by X-ray diffraction and vibrational spectroscopy. The compound crystallized in the monoclinic crystal system; crystal data: a=10.853(2) Å, b=7.937(2) Å, c=12.732(3) Å, β=112.13(3)°, V=1015.9(4)ų,Z=4,d_calc=1.466g/cm³,spacegroupP2₁/c,R_f=0.0486,GOOF=1.161.The S-O distances in the sulfonate group differed substantially (S1-O2 1.439(2) Å, S1-O3 1.455(2) Å, and S1-O4 1.464(2) Å. The symmetry of the H₅O₂ cation decreased due to proton displacement toward one of the two water molecules. XRD data on the asymmetry of H5O2 were confirmed by IR and Raman spectral data. The strong triplet at 2900, 3166, 3377 cm^?1 in the IR spectrum of I corresponds to different types of H-bond and shifted to 2185, 2363, 2553 cm^?1 after deuteration. The proton conductivity of the compound was measured by impedance spectroscopy: 6 × 10^?7 S/cm at 298 K (32 rel %), E _act=0.4±0.01 eV. The conductivity increased to 10^-3 S/cm, E_act=0.1 eV when ambient humidity increased to 60 rel %.