- Low-temperature thermoluminescence in solid argon: Short-range mobility of atoms
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The 193-nm photolysis of S2 (produced from H2S2) and SO2 in solid argon and the changes introduced by annealing are monitored by using Fourier-transform infrared spectroscopy and laser-induced fluorescence. The results highlight short-range atomic mobility distinguished from global long-range mobility. It is shown that under the 193-nm irradiation a small part of S2 and SO2 molecules undergo photodecomposition yielding quasi-isolated pairs where the fragments are in close vicinity to each other. In annealing, the short-range mobility results in recombination of these pairs at rather low temperatures (a static Ar lattice support this scenario, demonstrating that the photofragments can be gently separated by a low potential barrier which favors their recombination in annealing. In particular, this quasistable configuration occurs when the two atoms occupy substitutional sites separated by the lattice parameter of 5.31 A.
- Khriachtchev, Leonid,Pettersson, Mika,Pehkonen, Susanna,Isoniemi, Esa,Raesaenen, Markku
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- SO2 Fluorescence from Vacuum Ultraviolet Dissociative Excitation of SO3
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The absorption and fluorescence excitation spectra of SO3 were measured in the 145-160-nm region with synchrotron radiation as a light source.The fluorescence spectra produced by excitation of SO3 at 147 and 157 nm were dispersed and compared with the laser-induced fluorescence spectrum of SO2, from which the emitter is identified to be the excited SO2*.The photodissociation process of SO3 is discussed in accord with the fluorescence observed.
- Suto, Masako,Ye, Chao,Ram, R. S.,Lee, L. C.
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- Photodissociation of the SO2*SO2+ dimer in the visible region of the spectrum: Product relative kinetic energy distributions and product angular distributions
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The results of an investigation of the photodissociation of the SO2*SO2+ cluster ion in the visible wavelength range (458-590 nm) are presented.The studies were performed using a crossed fast ion beam/laser beam experiment.Product relative kinetic energy distributions and product center of mass angular distributions are reported.Methods used to extract the angular distributions from the experimental measurements are described.The only ionic product observed from the photodissociation of SO2*SO2+ was SO2+.The product relative kinetic energy distributions are characteristic of statistical energy disposal.However, statistical phase space theory substantially overestimates the fraction of available energy partitioned into relative kinetic energy.The product angular distributions are discussed in terms of the asymmetry parameter β. β increases with the products relative velocity.A simple phase space theory model for β is developed for statistical dissociation with complete rotational averaging.The model accounts for the variation of β with the products relative velocity. β also varies with wavelength.The variation of β with wavelength is ascribed to changes in the lifetime of the cluster.At 458 nm the values of β indicate that complete rotational averaging has not occurred.At 590 nm the data are consistent with complete rotational averaging, implying a lifetime>5 average rotational periods.The results are interpreted in terms of a transition to a low lying bound excited state of the SO2*SO2+ cluster which arises from one of the low lying excited states of SO2+ and the ground state of SO2.
- Jarrold, Martin F.,Illies, Andreas J.,Bowers, Michael T.
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- Non-isothermal kinetics of decomposition of A1NH4(SO4)2.12H2O by EGA-MS
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Materials Science Division, Indira Gandhi Centre for Atomic Research, Kalpakkam 603 102, Tamil Nadu, India Real-time multiple-ion detection trend analysis mass spectrometry has been employed to study the temperature-programmed decomposition of A1NH4(SO4)2. 12H2O in the temperature range 300-1200 K. Significant correlations are established with certain non-isothermal solid state kinetic rate expressions through the use of fraction release plots obtained from Evolved Gas Analysis Mass Spectra (EGA-MS). The EGA mass spectra clearly resolve the dehydration stage and various other stages associated with the thermal decomposition. The dehydration step is concomitant with stage I of a three-stage ammonia release followed by the final decomposition of A12(SO4)3. These stages are found to comply with models based on random nucleation and diffusion approaches. A change in rate-governing mechanism was noticed with increase in the heating rate for the dehydration step. Relevant Arrhenius parameters such as the activation energy and pre-exponential factor were determined for all the decomposition stages. The ultimate product resulting from the decomposition was confirmed as γ-alumina by X-ray diffraction studies.
- Kamruddin,Ajikumar,Dash,Krishnan,Tyagi,Krishan
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- Hydrolysis of aluminum sulfates in the presence of ammonium sulfite
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Hydrolysis of aluminum sulfate and potash alum in the presence of an ammonium sulfite additive in the temperature range T boil-200°C was studied. A possible reaction mechanism was suggested. The composition and structure of the precipitates formed were determined and certain differences in their morphology were noted. Recommendations for practical implementation of the method of hydrolytic recovery of aluminum from solutions of its sulfate salts were given.
- Matveev
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- Analysis of the chemical processes occurring in the system PbSO4-ZnS
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Research carried out on the interactions between PbSO4 and ZnS, using mixtures with variable molar ratios of PbSO4: ZnS, showed that the process starts at 803 K. It was found that a few reactions occur at the same time, including transformation of zinc sulfide into its oxide and PbS formation; the secondary lead sulfate containing the sulfur from ZnS also appears. The PbS is derived primarily from PbSO4, and some of it contains the sulfur from ZnS.
- Malinowski, Czeslaw,Malinowska, Kazimiera,Malecki, Stanislaw
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- Stages of thermal decomposition of sodium oxo-salts of sulphur
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Thermal behaviour of sodium oxo-salts of sulphur: Na2SO 4, Na2S2O7, Na2S 2O6, Na2SO3, Na2S 2O5, Na2S
- Jaszczak-Figiel, Beata,Gontarz
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- Synthesis and properties of Na6[Pb(S2O 3)4] · 6H2O
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Conditions for the synthesis of the water-soluble lead thiosulfate complex Na6[Pb(S2O3)4] · 6H2O were determined. The complex synthesized was characterized by UV and IR spectroscopy and X-ray phase and thermal a
- Egorov
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- TG-GC-MS, TG-MS and TG-FTIR applications on polymers and waste products
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A latex is studied using the off-line combination, TG-GC-MS. A mixture, CuSO4·5H2O-cellulose, is studied using the online combination, TG-MS, and the amount of HCN in gases released by heating of a waste product is determined using the online combination of TG-FTIR, successive sampling, FIA and photometry.
- Reggers,Ruysen,Carleer,Mullens
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- Thermal dissociation of so3 at 1000-1400 K
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The thermal dissociation of SO3 has been studied for the first time in the 1000-1400 K range. The experiments were conducted in a laminar flow reactor at atmospheric pressure, with nitrogen as the bath gas. On the basis of the flow reactor data, a rate constant for SO3 + N2 → SO2 + O + N2 (Rib) of 5.7 × 1017 exp(-40000/T) cm3/(mol s) is derived for the temperature range 1273-1348 K. The estimated uncertainty is a factor of 2. The rate constant corresponds to a value of the reverse reaction of k1 ≈ 1.8 × 1015 cm6 mol-2 s-1. The reaction is in the falloff region under the investigated conditions. The temperature and pressure dependence of SO2 + O (+N2) was estimated from the extrapolation of low temperature results for the reaction, together with an estimated broadening parameter and the high-pressure limit determined recently by Naidoo, Goumri, and Marshall (Proc. Combust. Inst. 2005, 30, 1219-1225). The theoretical rate constant is in good agreement with the experimental results. The improved accuracy in k1 allows a reassessment of the rate constant for SO3 + O → SO2 + O2 (R2) based on the data of Smith, Tseregounis, and Wang (Int. J. Chem. Kinet. 1982, 14, 679-697), who conducted experiments on a low-pressure CO/O2Ar flame doped with SO2. At the location in the flame where the net SO 3 formation rate is zero, k2 = k1[SO 2][M]/[SO3]. A value of 6.9 × 1010 cm3 mol-1 s-1 is obtained for k2 at 1269 K with an uncertainty a factor of 3. A recommended rate constant k 2 = 7.8 × 1011 exp(-3065/T) cm3 mol -1 s-1 is consistent with other flame results as well as the present flow reactor data.
- Yilmaz, Ayten,Hindiyarti, Lusi,Jensen, Anker D.,Glarborg, Peter,Marshall, Paul
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- A kinetic study of the thermal decomposition process of potassium metabisulfite: Estimation of distributed reactivity model
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The thermal decomposition kinetics of potassium metabisulfite was studied by thermogravimetric (TG) and differential thermogravimetric (DTG) techniques using non-isothermal experiments. The apparent activation energy (Ea) is determined using the differential (Friedman) isoconversional method. The results of the Friedman's isoconversional analysis of the TG data suggests that the investigated decomposition process follows a single-step reaction and the observed apparent activation energy was determined as 122.4±2.1 kJ mol-1. A kinetic rate equation was derived for the decomposition process of potassium metabisulfite with contracting area model, f(α)=2(1-α)1/2, which is established using the Malek's kinetic procedure. The value of pre-exponential factor (A) is also evaluated and was found to be A=1.37×1012 min-1. By applying the Miura's procedure the distributed reactivity model (DRM) for investigated decomposition process was established. From the dependence α versus Ea, the experimental distribution curve of apparent activation energies, f(Ea), was estimated. By applying the non-linear least-squares analysis, it was found that the Gaussian distribution model (with distribution parameters E0=121.3 kJ mol-1 and σ=1.5 kJ mol-1) represents the best reactivity model for describing the investigated process. Using the Miura's method, the A values were estimated at five different heating rates and the average A values are plotted against Ea. The linear relationship between the A and Ea values was established (compensation effect). Also, it was concluded that the Ea values calculated by the Friedman's method and estimated distribution curve, f(Ea), are correct even in the case when the investigated decomposition process occurs through the single-step reaction mechanism.
- Jankovi?,Mentus,Jankovi?
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- Pt-core silica shell nanostructure: a robust catalyst for the highly corrosive sulfuric acid decomposition reaction in sulfur iodine cycle to produce hydrogen
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The platinum core silica shell catalyst has facilitated stable sulfuric acid decomposition at higherature which was not possible over bare Pt nanoparticles due to sintering and agglomeration. Helium (He) gas supplies the heat (550-900 °C) in a high temperature gas cooled reactor (VHTR). The major challenge is designing a stable catalyst for the variable heat efficiency of He. Pt catalysts loaded on different supports, such as SiC, Al2O3, SiC-Al2O3, BaSO4, TiO2, SBA-15, and SiO2, have been extensively studied but they have not provided a simple method to form robust catalysts for sulfuric acid decomposition. The core-shell scheme, whereby nanoparticles are enclosed by protecting agents (CTAB) and are covered by a silica shell, delivered mesopores and exhibited higher activity and stability over testing for more than 100 h. TEM images confirmed that the Pt particles on the Pt@mSiO2 catalyst are more stable during sulfuric acid decomposition, and no significant evidence of agglomeration or sintering of the Pt core particles was found, despite some broken shells and dislocated Pt nanoparticles from the silica core. ICP-OES analysis of the spent catalysts after 100 h showed minimal Pt loss (9.0%). These types of catalysts are highly desirable for practical applications. This journal is
- Khan, Hassnain Abbas,Jung, Kwang-Deog,Ahamad, Tansir,Ubaidullah, Mohd,Imran, Muhammad,Alshehri, Saad M.
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- In Situ Modulation of A-Site Vacancies in LaMnO3.15 Perovskite for Surface Lattice Oxygen Activation and Boosted Redox Reactions
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Modulation of A-site defects is crucial to the redox reactions on ABO3 perovskites for both clean air application and electrochemical energy storage. Herein we report a scalable one-pot strategy for in situ regulation of La vacancies (VLa) in LaMnO3.15 by simply introducing urea in the traditional citrate process, and further reveal the fundamental relationship between VLa creation and surface lattice oxygen (Olatt) activation. The underlying mechanism is shortened Mn?O bonds, decreased orbital ordering, promoted MnO6 bending vibration and weakened Jahn–Teller distortion, ultimately realizing enhanced Mn-3d and O-2p orbital hybridization. The LaMnO3.15 with optimized VLa exhibits order of magnitude increase in toluene oxidation and ca. 0.05 V versus RHE (reversible hydrogen electrode) increase of half-wave potential in oxygen reduction reaction (ORR). The reported strategy can benefit the development of novel defect-meditated perovskites in both heterocatalysis and electrocatalysis.
- Chen, Jianjun,Ding, Yun,He, Minghua,Li, Junhua,Liu, Haiyan,Liu, Jun,Liu, Xiaoqing,Liu, Yuefeng,Mi, Jinxing,Shi, Jianqiang,Shi, Lin,Wang, Zisha,Wu, Zhong-Shuai,Xiong, Shangchao,Zhang, Qinfang
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supporting information
p. 26747 - 26754
(2021/11/17)
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- Oxidation of Sulfur Dioxide in Sodium and Calcium Fluorides
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Abstract: It was established that the oxidation reactions of sulfur dioxide occur in aqueous solutions of sodium fluoride and in suspensions of calcium fluoride at room temperature and atmospheric pressure. It was found that the solutions of NaF and CaFs
- Ivanova, M. S.,Savitskaya, Yu. V.,Tomskii, K. O.,Vishnetskaya, M. V.
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p. 513 - 517
(2021/08/23)
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- The tin sulfates Sn(SO4)2and Sn2(SO4)3: Crystal structures, optical and thermal properties
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We report the crystal structures of two tin(iv) sulfate polymorphs Sn(SO4)2-I (P21/c (no. 14), a = 504.34(3), b = 1065.43(6), c = 1065.47(6) pm, β = 91.991(2)°, 4617 independent reflections, 104 refined parameters, wR2 = 0.096) and Sn(SO4)2-II (P21/n (no. 14), a = 753.90(3), b = 802.39(3), c = 914.47(3) pm, β = 92.496(2)°, 3970 independent reflections, 101 refined parameters, wR2 = 0.033). Moreover, the first heterovalent tin sulfate Sn2(SO4)3 is reported which adopts space group P1 (no. 2) (a = 483.78(9), b = 809.9(2), c = 1210.7(2) pm, α = 89.007(7)°, β = 86.381(7)°, γ = 73.344(7)°, 1602 independent reflections, 152 refined parameters, wR2 = 0.059). Finally, SnSO4-the only tin sulfate with known crystal structure-was revised and information complemented. The optical and thermal properties of all tin sulfates are investigated by FTIR, UV-vis, luminescence and 119Sn M?ssbauer spectroscopy as well as thermogravimetry and compared.
- Daub, Michael,H?mmer, Matthias,H?ppe, Henning A.,Hillebrecht, Harald,Klenner, Steffen,Netzsch, Philip,Neuschulz, Kai,P?ttgen, Rainer,Struckmann, Mona,Wickleder, Mathias S.
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p. 12913 - 12922
(2021/10/12)
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- Metal- And Base-Free C(sp2)-H Arylsulfonylation of Enamides for Synthesis of (E)-β-Amidovinyl Sulfones via the Insertion of Sulfur Dioxide
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A metal- and base-free C(sp2)-H direct arylsulfonylation of secondary and tertiary enamides with aryldiazonium salts and ex situ generated SO2 (from SOgen) is presented. This method runs smoothly to produce β-amidovinyl sulfones with excellent stereoselectivities in moderate to excellent yields. Moreover, this strategy features good functional group tolerance and environmentally benign reaction conditions. Mechanistic experiments indicate that this sulfonylation may proceed in a radical pathway.
- Chen, Lei,Zhou, Mi,Shen, Lin,He, Xiaochun,Li, Xiong,Zhang, Xuemei,Lian, Zhong
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supporting information
p. 4991 - 4996
(2021/06/30)
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- Copper-Catalyzed Chloro-Arylsulfonylation of Styrene Derivatives via the Insertion of Sulfur Dioxide
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A copper-catalyzed four-component chloro-arylsulfonylation of styrene derivatives with aryldiazonium tetrafluoroborates, lithium chloride, and ex-situ generated sulfur dioxide (from SOgen) is presented. This sulfonylation features good functional group compatibility, mild reaction conditions, excellent regioselectivity, and good yields. The robustness and potential of this method have also been successfully demonstrated by a gram-scale reaction. Based on experimental study, a radical-involved mechanism is proposed for the transformation.
- Li, Yue,Shen, Lin,Zhou, Mi,Xiong, Baojian,Zhang, Xuemei,Lian, Zhong
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supporting information
p. 5880 - 5884
(2021/08/01)
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- Defect enriched N-doped carbon nanoflakes as robust carbocatalysts for H2S selective oxidation
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Nanocarbons have emerged as low-cost, efficient and durable nonmetallic catalysts for H2S selective oxidation. However, the most efficient active sites for H2S activation remain elusive, which restricts further development of high-pe
- Cao, Ning,Chen, Congmei,Gu, Qingqing,Jiang, Chengfa,Jiang, Qian,Li, Shiyan,Liu, Yuefeng,Pham-Huu, Cuong,Xu, Chi
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p. 8892 - 8902
(2020/06/10)
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- Efficient and Practical Synthesis of Sulfonamides Utilizing SO2 Gas Generated on Demand
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A simple and practical protocol was developed for the synthesis of sulfonamides by reacting organometallic reagents with SO2 gas generated on demand. SO2 was generated from readily available reagents safely in a highly contained and controlled fashion. The protocol allows the synthesis of sulfonamides without using either atom-inefficient SO2 surrogates or a SO2 cylinder that requires stringent storage regulations in the laboratory. The protocol was successfully applied to the synthesis of sildenafil.
- Chung Leung, Gulice Yiu,Ramalingam, Balamurugan,Loh, Gabriel,Chen, Anqi
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p. 546 - 554
(2020/04/22)
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- Capture of the Sulfur Monoxide-Hydroxyl Radical Complex
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The elusive hydrogen-bonded sulfur monoxide-hydroxyl radical complex (?OH···OS), a missing intermediate in the atmospheric chemistry of SO2, was generated in the 266 nm laser photolysis of the sulfinyl radical HOSO?in cryogenic Ar-matrixes. In addition to the IR spectroscopic characterization with deuteration, its thermal conversion to HOSO?with an activation barrier of 0.33 ± 0.11 kcal mol-1 (calcd 0.32 kcal mol-1, CCSD(T)-F12a/AVTZ) in the temperature range of 15.0-21.0 K and a H/D kinetic isotope effect of 2.4 at 16.0 K have been observed.
- Chen, Changyun,Lu, Bo,Zhao, Xiaofang,Qian, Weiyu,Liu, Jie,Trabelsi, Tarek,Francisco, Joseph S.,Qin, Jie,Li, Jun,Wang, Lina,Zeng, Xiaoqing
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supporting information
p. 2175 - 2179
(2020/03/03)
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- Green molten salt synthesis and Li-ion storage performance of sodium dimolybdate
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A facile and fast molten salt strategy is developed, for the first time, to synthesis sodium dimolybdate (Na2Mo2O7). The process is based on a thermodynamically favorable reaction between naturally available precursors MoS2 and NaCl to produce Na2Mo2O7 as well as a gas phase that leaves the system. The product is characterized by electron microscopy and energy-dispersive X-ray spectroscopy (EDX) as well as X-ray diffraction (XRD) and Raman spectroscopy. The prepared Na2Mo2O7 in combination with molten salt-synthesized graphene nanosheets is examined as anode material for Li-ion batteries, exhibiting an interesting performance, with the first cycle discharge and charge capacities of 1363 and 857 mAh g?1, respectively, at 100 mA g?1. A reversible Li storage capacity of 506 mAh g?1 can still be observed after 100 cycles. The results are rather interesting towards the development of low-cost and high-performance Na2Mo2O7 anode materials.
- Kamali, Ali Reza,Zhu, Wenhui
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- Reversible uptake of sulfur-containing gases by single crystals of a Cr 8 metallacrown
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The exposure of green crystals of the [CrF(O2CtBu)2]8Cr8 metallacrown to SO2 and H2S gases results in the binding of the gas molecules in the internal molecular cavity, despite the absence of any pores or channels in the structure. Single crystal X-ray diffraction studies show that the gas molecules bind weakly to the bridging fluoride ligands. The desorption process was followed by TGA, DSC and in situ variable temperature single crystal X-ray diffraction, obtaining the gas binding energies for the gas guest molecules. These results are supported by DFT calculations.
- Vitórica-Yrezábal, I?igo J.,Sava, Daniel Florin,Reta, Daniel,Timco, Grigore A.,Winpenny, Richard E. P.
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supporting information
p. 13184 - 13189
(2019/09/18)
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- Pt black catalyzed methane oxidation to methyl bisulfate in H2SO4-SO3
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Although chloride-ligated Pt compounds like (bpym)PtCl2, K2PtCl4, and (DMSO)2PtCl2 has been reported to be highly active catalysts for the methane oxidation to methyl bisulfate (MBS) in oleum media, their applications is hampered by the catalyst deactivation to PtCl2. In this study, we investigated Pt black catalyzed methane oxidation, which has no ligand. A MBS yield of 82.1% with a selectivity of 96.5% was obtained at a catalyst loading of 1.6 mM at 180 °C, which proved the highest catalytic activity of Pt-black for this reaction. The reaction was thought to proceed by the dissolved Pt species, and no deactivation was observed during four consecutive experiments. However, at a concentration of over 30 mM, MBS yield fell due to the decomposition of MBS to CO2 on the surface of heterogeneous Pt(0). Vacuum distillation experiments showed the potential for isolating MBS from the oxidation product mixture as a major component.
- Lee, Hee Won,Dang, Huyen Tran,Kim, Honggon,Lee, Ung,Ha, Jeong-Myeong,Jae, Jungho,Cheong, Minserk,Lee, Hyunjoo
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p. 230 - 236
(2019/05/17)
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- A highly selective and sensitive H2S sensor at low temperatures based on Cr-doped α-Fe2O3 nanoparticles
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Cr-doped α-Fe2O3 nanoparticles were synthesized by a low-cost and environmentally friendly hydrothermal route. Their gas sensing properties were investigated and the sensor showed high sensitivity and selectivity to H2S gas. Different Cr doping levels from 0 to 8.0 wt% were studied, and the sensor of 4.0 wt% Cr-doped α-Fe2O3 showed the largest response, with a response of 213 to 50 ppm H2S at 100 °C. The incorporation of Cr ions within α-Fe2O3 nanocrystals increases the specific surface area, and promotes the oxidation of H2S and oxygen adsorption in the air. Thus, the doping of Cr into α-Fe2O3 nanostructures would be a promising method for designing and fabricating high performance H2S gas sensors.
- Xue, Dongyang,Zhou, Rui,Lin, Xiaoping,Duan, Xiaochuan,Li, Qiuhong,Wang, Taihong
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p. 4150 - 4156
(2019/02/25)
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- A simple design of fluorescent probes for indirect detection of β-lactamase based on AIE and ESIPT processes
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A novel fluorescent probe DNBS-CSA is developed for light-up detection of β-lactamase. The probe design is based on an indirect detection approach with three step reactions. β-Lactamase can react with the lactam of its substrate (cefazolin sodium) to prod
- Peng, Lu,Xiao, Lu,Ding, Yiwen,Xiang, Yu,Tong, Aijun
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supporting information
p. 3922 - 3926
(2018/06/21)
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- Photoinduced Sulfur-Nitrogen Bond Rotation and Thermal Nitrogen Inversion in Heterocumulene OSNSO
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An exotic ternary S, N, O heterocumulene OSNSO in syn-syn (A) and syn-anti (B) conformations has been generated in the gas phase through flash vacuum pyrolysis of CF3S(O)NSO at 700 K. Upon visible light irradiation (570 ± 20 or 532 nm), both A and B, isolated in cryogenic matrices (N2, Ne, Ar, and Kr, a higher-energy anti-anti conformer (C). The reverse conformational transformation occurs either through S=N bond rotation (C to A and B) under visible light irradiation (400 ± 20 nm) at 2.8 K or through thermal nitrogen inversion (C to A) in the temperature range of 20-30 K, for which an exceptionally low activation barrier of 1.18 ± 0.07 kcal mol-1 has been experimentally determined.
- Wu, Zhuang,Feng, Ruijuan,Xu, Jian,Lu, Yan,Lu, Bo,Yang, Tao,Frenking, Gernot,Trabelsi, Tarek,Francisco, Joseph S.,Zeng, Xiaoqing
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p. 1231 - 1234
(2018/02/09)
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- Esterase Sensitive Self-Immolative Sulfur Dioxide Donors
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A series of cell-permeable esterase-sensitive sulfonates that undergo self-immolation to produce sulfur dioxide (SO2), a gaseous pollutant with new and emerging biological roles, is reported. These compounds should facilitate the study SO2 biology and will lay the platform for newer stimuli-responsive donors of this gas.
- Pardeshi, Kundansingh A.,Ravikumar, Govindan,Chakrapani, Harinath
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supporting information
p. 4 - 7
(2018/01/12)
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- Novel synthetic route to perfluoroallyl cyanide (PFACN) reacting perfluoroallyl fluorosulfonate with cyanide
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A novel synthetic method for the preparation of perfluoroallyl cyanide CF2[dbnd]CFCF2CN (PFACN) is presented. This includes the addition – elimination reaction of cyanide anion with perfluoroallyl fluorosulfate CF2[dbnd]CF
- Tverdomed, Sergey N.,Hirschberg, Markus E.,Pajkert, Romana,Hintzer, Klaus,R?schenthaler, Gerd-Volker
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- Capture of SO3 isomers in the oxidation of sulfur monoxide with molecular oxygen
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When mixing SO with O2 in N2, Ne, or Ar, an end-on complex OS-OO forms in the gas phase and can subsequently be trapped at cryogenic temperatures (2.8-15.0 K). Upon infrared light irradiation, OS-OO converts to SO3 and SO2 + O with the concomitant formation of a rare 1,2,3-dioxathiirane 2-oxide, i.e., cyclic OS(O)O. Unexpectedly, the ring-closure of 16OS-18O18O yields a ca. 2:1 mixture of cyclic 18OS(16O)18O and 16OS(18O)18O. The characterization of OS-OO and OS(O)O with IR and UV/Vis spectroscopy is supported by high-level ab initio computations.
- Wu, Zhuang,Lu, Bo,Feng, Ruijuan,Xu, Jian,Lu, Yan,Wan, Huabin,Eckhardt, André K.,Schreiner, Peter R.,Xie, Changjian,Guo, Hua,Zeng, Xiaoqing
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supporting information
p. 1690 - 1693
(2018/02/21)
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- Does Tetrahydrofuran (THF) Behave like a Solvent or a Reactant in the Photolysis of Thionyl Chloride (Cl2SO) in Cyclohexane? A Transient Infrared Difference Study
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The photolysis of thionyl chloride (Cl2SO) in pure cyclohexane (cHex) and in cHex with a small amount of tetrahydrofuran (THF) irradiated with 266 nm pulsed laser was investigated using time-resolved step-scan Fourier-transform spectroscopy. The density functional theory B3LYP, with the conductor-like polarizable continuum model to account for the effects of solvents, was employed to predict the molecular parameters of the relevant species. Monitoring the wavenumbers and infrared absorbances attributed to the [S,O] species and accounting for the stoichiometry revealed SO2 to be the major oxygen-containing end product for the thermal decomposition of Cl2SO. Upon successive irradiation with 266 nm pulsed laser, the major product, as detected by IR absorption, was S2O with minor SO3, which could be generated from the secondary reactions of the photolytic intermediate ClSO. The majority of the transient vibrational features upon 266 nm irradiation of the mixture of Cl2SO/cHex was attributed to ClSO, characterized at 1155 cm-1, coupled with a minor contribution of (ClSO)2 at 1212 and 1173 cm-1. For the mixture of Cl2SO/THF/cHex, the transient population of ClSO was retained, but the amount of (ClSO)2 was slightly reduced, coupled with a new upward feature at 1054 cm-1 that was plausibly attributed to the C-O-C asymmetric stretching mode of ClSO-THF complex. Upon the successive irradiation of the Cl2SO/THF/cHex mixture, the amount of S2O was also decreased. The observed complexes of THF with solutes suggested that THF should not be merely treated as a solvent but regarded as a coordination molecule in organic synthesis. The formation of the intermediate-THF complexes altered the reaction pathways, as well as the types and populations of the end products.
- Shih, Meng-Chen,Chu, Li-Kang
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p. 5401 - 5408
(2018/06/04)
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- Hydrolytic cleavage of both CS2 carbon-sulfur bonds by multinuclear Pd(II) complexes at room temperature
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Developing homogeneous catalysts that convert CS2 and COS pollutants into environmentally benign products is important for both fundamental catalytic research and applied environmental science. Here we report a series of air-stable dimeric Pd complexes that mediate the facile hydrolytic cleavage of both CS2 carbon-sulfur bonds at 25 °C to produce CO2 and trimeric Pd complexes. Oxidation of the trimeric complexes with HNO3 regenerates the dimeric starting complexes with the release of SO2 and NO2. Isotopic labelling confirms that the carbon and oxygen atoms of CO2 originate from CS2 and H2O, respectively, and reaction intermediates were observed by gas-phase and electrospray ionization mass spectrometry, as well as by Fourier transform infrared spectroscopy. We also propose a plausible mechanistic scenario based on the experimentally observed intermediates. The mechanism involves intramolecular attack by a nucleophilic Pd-OH moiety on the carbon atom of coordinated μ-OCS2, which on deprotonation cleaves one C-S bond and simultaneously forms a C-O bond. Coupled C-S cleavage and CO2 release to yield [(bpy)3Pd3(μ3-S)2](NO3)2 (bpy, 2,2'-bipyridine) provides the thermodynamic driving force for the reaction.
- Jiang, Xuan-Feng,Huang, Hui,Chai, Yun-Feng,Lohr, Tracy Lynn,Yu, Shu-Yan,Lai, Wenzhen,Pan, Yuan-Jiang,Delferro, Massimiliano,Marks, Tobin J.
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p. 188 - 193
(2017/03/20)
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- Gas-phase and matrix-isolation photochemistry of methyl thioglycolate, CH3OC(O)CH2SH: Influence of the presence of molecular oxygen in the photochemical mechanisms
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The photochemistry of methyl thioglycolate (MTG), CH3OC(O)CH2SH, in gas phase and in matrix isolation conditions was studied by means of FTIR spectroscopy, and the influence of the presence of molecular oxygen on the photochemical me
- Bava, Yanina B.,Tamone, Luciana M.,Juncal, Luciana C.,Seng, Samantha,Tobón, Yeny A.,Sobanska, Sophie,Picone, A. Lorena,Romano, Rosana M.
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p. 101 - 107
(2017/05/17)
-
- Comprehensive Insights into the Thermal Stability, Biodegradability, and Combustion Chemistry of Pyrrolidinium-Based Ionic Liquids
-
The use of ionic liquids (ILs) as advanced electrolyte components in electrochemical energy-storage devices is one of the most appealing and emerging options. However, although ILs are hailed as safer and eco-friendly electrolytes, to overcome the limitations imposed by the highly volatile/combustible carbonate-based electrolytes, full-scale and precise appraisal of their overall safety levels under abuse conditions still needs to be fully addressed. With the aim of providing this level of information on the thermal and chemical stabilities, as well as actual fire hazards, herein, a detailed investigation of the short- and long-term thermal stabilities, biodegradability, and combustion behavior of various pyrrolidinium-based ILs, with different alkyl chain lengths, counteranions, and cations, as well as the effect of doping with lithium salts, is described.
- Eshetu, Gebrekidan Gebresilassie,Jeong, Sangsik,Pandard, Pascal,Lecocq, Amandine,Marlair, Guy,Passerini, Stefano
-
p. 3146 - 3159
(2017/08/18)
-
- Aluminum-Catalyzed Formation of Functional 1,3,2-Dioxathiolane 2-Oxides from Sulfur Dioxide: An Easy Entry towards N-Substituted Aziridines
-
Aluminum(III) complexes derived from aminotriphenolate ligands are shown to be excellent catalysts for the formation of cyclic sulfites from a range of (functionalized) terminal and internal epoxides, and ex situ generated sulfur dioxide. The developed catalytic protocol is characterized by its operational simplicity, wide scope in epoxide reaction partners, good to excellent isolated yields and mild reaction conditions [50–70 °C, p(SO2) a three-step protocol. (Figure presented.).
- Laserna, Victor,Martin, Eddy,Escudero-Adán, Eduardo C.,Kleij, Arjan W.
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p. 3832 - 3839
(2016/12/16)
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- Autonomous movement induced in chemically powered active soft-oxometalates using dithionite as fuel
-
Synthesis of autonomously moving nano or micromotors is an immediate challenge in current nanoscience and nanotechnology. In this work we report a system based on soft-oxometalates (SOMs) which is very easy to synthesize and moves autonomously in response to chemical stimuli like that of a reducing agent-dithionite. The redox active MoVI sites of SOMs are used for oxidizing dithionite to generate SO2 to propel the micromotors. We explain this motion qualitatively and also show how surface interaction and adsorption isotherm of the evolved gas influence the power conversion efficiency of these micromotors.
- Mallick, Apabrita,Lai, Dipti,Roy, Soumyajit
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p. 1057 - 1062
(2016/02/19)
-
- Investigation of a Fe-N-C catalyst for sulfur dioxide electrooxidation
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A Fe-N-C catalyst, synthesized with porous carbon BP2000, the nitrogen source imidazole and iron source FeCl3, is developed for SO2 electrooxidation through a series of thermal and pyrolytic disposing processes. The electrochemical measurements of linear sweep voltammograms (LSV) and cyclic voltammograms (CV) are applied to investigate the SO2 oxidation performance of the catalyst. The results show that the half-wave oxidation potential of Fe-N-C is 283.8 mV lower than that of BP2000 meanwhile the onset oxidation potential reduces 58 mV as well, implying there is a highly improved SO2 oxidation performance of the catalyst. The structural and physical characteristics of the Fe-N-C catalyst are examined by the methods of TEM, XPS, XRD and Raman spectroscopy. The characterization proves the formation of graphitic carbon, iron carbides, single-layer graphene and defects as well as the existence of FeN/Fe2N, pyridinic N and Fe-N components on the prepared Fe-N-C catalyst, which are supposed to have significant effects on the SO2 electrooxidation performance.
- Zhao, Qing,Hou, Ming,Jiang, Shangfeng,Wang, Shengli,Ai, Jun,Zheng, Limin,Shao, Zhigang
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p. 80024 - 80028
(2017/04/03)
-
- Online Analysis of H2S and SO2 via Advanced Mid-Infrared Gas Sensors
-
Volatile sulfur compounds (VSCs) are among the most prevalent emitted pollutants in urban and rural atmospheres. Mainly because of the versatility of sulfur regarding its oxidation state (2- to 6+), VSCs are present in a wide variety of redox-environments, concentration levels, and molar ratios. Among the VSCs, hydrogen sulfide and sulfur dioxide are considered most relevant and have simultaneously been detected within naturally and anthropogenically caused emission events (e.g., volcano emissions, food production and industries, coal pyrolysis, and various biological activities). Next to their presence as pollutants, changes within their molar ratio may also indicate natural anomalies. Prior to analysis, H2S- and SO2-containing samples are usually preconcentrated via solid sorbents and are then detected by gas chromatographic techniques. However, such analytical strategies may be of limited selectivity, and the dimensions and operation modalities of the involved instruments prevent routine field usage. In this contribution, we therefore describe an innovative portable mid-infrared chemical sensor for simultaneously determining and quantifying gaseous H2S and SO2 via coupling a substrate-integrated hollow waveguides (iHWG) serving as a highly miniaturized mid-infrared photon conduit and gas cell with a custom-made preconcentration tube and an in-line UV-converter device. Both species were collected onto a solid sorbent within the preconcentrator and then released by thermal desorption into the UV-device. Hydrogen sulfide is detected by UV-assisted quantitative conversion of the rather weak IR-absorber H2S into SO2, which provides a significantly more pronounced and distinctively detectable rovibrational signature. Modulation of the UV-device system (i.e., UV-lamp on/off) enables discriminating between SO2 generated from H2S conversion and abundant SO2 signals. After optimization of the operational parameters, calibrations in the range of 0.75-10 ppmv with a limit of detection (LOD) at 77 ppbv for SO2 and 207 ppbv for H2S were established after 20 min of sampling time at 200 mL min-1. Taking advantage of the device flexibility in terms of sampling time, flow-rate, and iHWG design facilitates tailoring the developed Preconcentrator-UV-device-iHWG device toward a wide variety of application scenarios ranging from environmental/atmospheric monitoring to industrial process monitoring and clinical diagnostics.
- Petruci, Jo?o Flavio Da Silveira,Wilk, Andreas,Cardoso, Arnaldo Alves,Mizaikoff, Boris
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p. 9605 - 9611
(2015/10/12)
-
- Photochemistry of matrix isolated (Trifluoromethyl)sulfonyl azide, CF3SO2N3
-
The photochemistry of matrix isolated (trifluoromethylsulfonyl) azide, CF3SO2N3, has been studied at low temperatures. Upon ArF laser irradiation (λ = 193 nm), the azide eliminates N2 and furnishes triplet [(trifluoromethyl)sulfonyl]nitrene, CF3SO2N, which has been characterized by IR and EPR spectroscopy. Upon subsequent UV light irradiation (λ = 260-400 nm) the nitrene converts to CF3N=SO2 and CF3S(O)NO through a Curtius-type rearrangement. Further two new species CF2N=SO2F and FSNO were identified together with CF2NF, SO2, F2CO, CF3NO, and SO as side products. In addition, triplet nitrene CF3N was detected by its EPR and IR spectra. The complex stepwise photodecomposition of matrix isolated CF3SO2N3 is discussed in terms of the observed photolysis products and quantum chemical calculations.
- Zeng, Xiaoqing,Beckers, Helmut,Willner, Helge,Neuhaus, Patrik,Grote, Dirk,Sander, Wolfram
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p. 2281 - 2288
(2015/03/30)
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- Thiol activated prodrugs of sulfur dioxide (SO2) as MRSA inhibitors
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Drug resistant infections are becoming common worldwide and new strategies for drug development are necessary. Here, we report the synthesis and evaluation of 2,4-dinitrophenylsulfonamides, which are donors of sulfur dioxide (SO2), a reactive sulfur species, as methicillin-resistant Staphylococcus aureus (MRSA) inhibitors. N-(3-Methoxyphenyl)-2,4-dinitro-N-(prop-2-yn-1-yl)benzenesulfonamide (5e) was found to have excellent in vitro MRSA inhibitory potency. This compound is cell permeable and treatment of MRSA cells with 5e depleted intracellular thiols and enhanced oxidative species both results consistent with a mechanism involving thiol activation to produce SO2.
- Pardeshi, Kundansingh A.,Malwal, Satish R.,Banerjee, Ankita,Lahiri, Surobhi,Rangarajan, Radha,Chakrapani, Harinath
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p. 2694 - 2697
(2015/06/08)
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- A diarylethene as the SO2 gas generator upon UV irradiation
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A closed-ring isomer of a diarylethene having a sulfone group works as the reagent for SO2 gas generation with thermal stability even at 70°C, and it rapidly reverts to the open-ring isomer and generates the SO2 gas to induce cell death upon UV irradiation.
- Kodama, Ryuhei,Sumaru, Kimio,Morishita, Kana,Kanamori, Toshiyuki,Hyodo, Kengo,Kamitanaka, Takashi,Morimoto, Masakazu,Yokojima, Satoshi,Nakamura, Shinichiro,Uchida, Kingo
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p. 1736 - 1738
(2015/03/05)
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- Molten copper hexaoxodivanadate: An efficient catalyst for SO3 decomposition in solar thermochemical water splitting cycles
-
Molten copper hexaoxodivanadate (CuV2O6) was identified as an active catalyst for SO3 decomposition, which is an oxygen generation step in solar thermochemical water splitting cycles, at moderate temperatures (ca. 600 °C). The SO3 decomposition over CuV2O6 was significantly accelerated when the reaction temperature approached the melting point (ca. 630 °C) compared with solid phases of Cu2V2O7 as well as other compounds in the CuO-V2O5 system with higher melting points (≥780 °C). A possible intermediate CuSO4 species formed by SO 3 adsorption onto the Cu oxide site may decompose promptly to evolve SO2 and O2 on contact with the molten catalyst phase. Furthermore, the molten catalyst contained a large fraction of monovalent Cu formed by spontaneous desorption of oxygen. A possible reaction mechanism consisting of the fast dissolution of CuSO4 and Cu 2+/Cu+ redox cycles in the melt is proposed.
- Kawada, Takahiro,Tajiri, Tonami,Yamashita, Hiroaki,Machida, Masato
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p. 780 - 785
(2014/03/21)
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- THIOL MEDIATED/ACTIVATED PRODRUGS OF SULFUR DIOXIDE (SO2) HAVING ANTI-BACTERIAL ACTIVITY
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Disclosed herein are thiol mediated/activated prodrugs of SO2, particularly 2,4-dinitrophenylsulfonamide analogues, having Formula-I or pharmaceutically acceptable salts thereof exhibiting tunable release profiles of SO2 with significant therapeutic efficacy against bacterial infections. Further, the present invention provides pharmaceutical compositions comprising compound of Formula I or pharmaceutically acceptable salts thereof, along with pharmaceutically acceptable carriers/excipients.
- -
-
Paragraph 0142; 0122
(2014/05/08)
-
- Benzosultines as sulfur dioxide (SO2) donors
-
In order to understand precise biological roles of sulfur dioxide (SO 2), reliable SO2 donors, compounds that produce SO 2 under physiological conditions, are necessary. The design and development of 1-phenyl-benzosultine as an efficient SO2 donor is reported. This compound undergoes cycloreversion to generate SO2 upon dissolution in aqueous buffer at 37 C with a yield of 89% and a half-life of 39 min and shows SO2-like biological activity in a DNA cleavage assay.
- Malwal, Satish R.,Gudem, Mahesh,Hazra, Anirban,Chakrapani, Harinath
-
supporting information
p. 1116 - 1119
(2013/04/23)
-
- Selective oxidation of H2S over V2O5 supported on CeO2-intercalated Laponite clay catalysts
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A series of V2O5 supported on CeO2- intercalated clay catalysts (named V2O5/Ce-Lap catalysts) with mesoporous structure and high specific surface area were prepared. The structural characteristics and physicochemical properties were studied in detail. These catalysts were evaluated for the H2S selective oxidation. It was revealed that all V2O5/Ce-Lap catalysts showed high catalytic activities in the temperature range of 120-220 °C due to the redox reaction of highly dispersed V5+ species, and the catalytic mechanism obeyed a redox process, i.e. a stepwise mechanism. Additionally, the chemically absorbed oxygen also played an important role in H2S selective oxidation. Among them, the 5% V2O 5/Ce-Lap catalyst presented the best catalytic activity and excellent regenerability at 180 °C. Finally, the catalyst deactivation mechanism was explored.
- Zhang, Xin,Dou, Guangyu,Wang, Zhuo,Cheng, Jie,Wang, Hailin,Ma, Chunyan,Hao, Zhengping
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p. 2778 - 2785
(2013/09/24)
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- Thermally persistent fluorosulfonyl nitrene and unexpected formation of the fluorosulfonyl radical
-
Thermally persistent triplet sulfonyl nitrene, FSO2N, was produced in the gas phase in high yields (up to 66%) by flash vacuum pyrolysis of FSO2N3. Surprisingly, no rearrangement of FSO 2N was observed, but the
- Zeng, Xiaoqing,Beckers, Helmut,Willner, Helge
-
p. 2096 - 2099
(2013/04/23)
-
- Synthesis of [N(CH3)4]2O 3SOSO2(s) and [N(CH3)4] 2[(O2SO)2SO2]·SO 2(s) Containing (SO4)(SO2)x 2- x = 1, 2, members of a new class of sulfur oxydianions
-
One mole equivalent of SO2 reversibly reacts with [N(CH 3)4]2SO4(s) to give [N(CH 3)4]2S2O6(s) (1) containing the [O3SOSO2]2-, shown by Raman and IR to be an isomer of the [O3SSO3]2- dianion. The experimental and calculated (B3PW91/6-311+G(3df)) vibrational spectra are in excellent agreement, and the IR spectrum is similar to that of the isoelectronic O3ClOClO2. Crystals of [N(CH 3)4]2(O2SO)2SO 2·SO2 (2) were isolated from solutions of [N(CH3)4]2SO4 in liquid SO 2. The X-ray structure showed that 2 contained the [(O 2SO)2SO2]2- dianion. The characterized N(CH3)4+ salts 1 and 2 are the first two members of the (SO4)(SO2)x 2- class of sulfur oxydianions analogous to the well-known small cation salts of the SO4(SO3)x2- polysulfates.
- Bruna, Pablo,Decken, Andreas,Grein, Friedrich,Passmore, Jack,Rautiainen, J. Mikko,Richardson, Stephanie,Whidden, Tom
-
supporting information
p. 7193 - 7202
(2013/07/26)
-
- The iminyl radical O2SN
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The novel iminyl radical O2SN, a SO3 analogue, was produced by flash vacuum pyrolysis of gaseous alkyl sulfonyl azides RSO 2N3 (R=CF3, CH3) mixed with argon. Photoisomerization (λ>360 nm) of O2SN into planar syn-OSNO and anti-OSNO (see picture) was observed in solid noble-gas matrices. Copyright
- Zeng, Xiaoqing,Beckers, Helmut,Willner, Helge
-
supporting information
p. 7981 - 7984
(2013/08/23)
-
- Acetone condensation over sulfated zirconia catalysts
-
The aldol condensation reaction over sulfated zirconia led to the production of diacetone alcohol, which was further dehydrated forming mesityl oxide. The sulfated zirconia was obtained from zirconium acetate ethane sulfonate as a single source precursor. Oxides were obtained by calcinations of the precursors at 550-650 C, while the self-condensation reaction of acetone was carried out at 150 C. The precursor and the produced oxides were characterized using various characterization techniques. The precursors were synthesized with different acetate to ethane sulfonate ratio, ranging from 1 to 3. The major products obtained from the condensation reaction over the resulted oxide were mesityl oxide, mesitylene isophorone, naphthalene, and pentamers. The selectivity of mesityl oxide was approximately 100 % at the initial time-on-stream.
- Al-Hazmi, Mohammed H.,Choi, Yongman,Apblett, Allen W.
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p. 705 - 716
(2013/07/26)
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- Ion chemistry of sulfuryl fluoride: An experimental and theoretical study on gas-phase reactions involving neutral and ionized SO2F2
-
The gas phase ion chemistry of sulfuryl fluoride is studied by ion trap mass spectrometry and ab initio calculations. Reactions of ions of atmospheric relevance with neutral SO2F2 mainly result in SO 2F2 depletion by dissociative electron transfer. In few cases, a different reaction mechanism involving F-abstraction is invoked, since dissociative ion products are observed despite the electron transfer channel being endothermic. Ab initio calculations revealed a nearly perfect distonic structure for the molecular SO2F2+ ion, whose capability of activating strong HX bonds (X = C, N, O) is ascribable to the high spin density located on the oxygen atoms, in line with literature reports. Among the ions produced by electron ionization of SO2F2, the FSOx+ (x = 0-2) ions are capable of activating the HNH2 bond of ammonia. Theoretical investigation revealed that NH 3 activation by SF+ requires a triplet to singlet conversion along the reaction pathway. This conversion is expected to be fast, the conceivable reaction rate determining step being the subsequent intramolecular hydrogen migration.
- Antoniotti, Paola,Benzi, Paola,Operti, Lorenza,Rabezzana, Roberto,Borocci, Stefano,Giordani, Maria,Grandinetti, Felice
-
-
- Using Methanesulfonyl Halide as a Key Intermediate for Methane Gas to Liquid Conversion and Raw Commodity Chemical Generation
-
Processes for converting a methane or a methane containing natural gas to a monohalogenated methane and other downstream basic commodity chemicals going through methanesulfonyl halide as a key intermediate, whereby following its formation, the methanesulfonyl halide is allowed to decompose under a substantially anhydrous condition, preferably in the presence of a catalyst complex, and whereby in addition to the monohalogenated halide, a hydrogen halide and a sulfur dioxide are also formed in the overall conversion, both of which may be recycled back to the beginning of the processes. Additionally, compositions utilizing such a key intermediate for the same purposes are also disclosed.
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Page/Page column 6
(2012/05/04)
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- Design, synthesis and characterization of vanadia-doped iron-oxide pillared montmorillonite clay for the selective catalytic oxidation of H2S
-
A series of vanadia-doped iron-oxide-pillared clays (V/Fe-PILCs) with various amounts of vanadia were prepared and their performance for the selective catalytic oxidation of H2S was investigated. V/Fe-PILCs were characterized using X-ray diffraction (XRD), surface area- and pore volume measurements, chemical analysis, Fourier-transform infrared (FTIR) spectroscopy, X-ray photoelectron spectroscopy (XPS), and temperature-programmed reduction by H2 (H2-TPR). V/Fe-PILCs showed better catalytic performance than Fe-PILC without any significant SO2 emissions. The H2S conversion over V/Fe-PILCs increased with increasing vanadia content up to 7 wt.%. However, it decreased at higher vanadia loading due to the decrease in surface area and the formation of the crystalline V 2O5 phase. The presence of water vapor in the reactant mixture resulted in a decrease of H2S conversion.
- Bineesh, Kanattukara Vijayan,Kim, Dong-Kyu,Kim, Moon-Il,Selvaraj, Manickam,Park, Dae-Won
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p. 3938 - 3945
(2011/06/18)
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- Effect of calcination temperature on the physicochemical and catalytic properties of FeSO4/SiO2 in hydrogen sulfide oxidation
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The effect of calcination temperature on the state of the active component of iron-containing catalysts prepared by the impregnation of silica gel with a solution of FeSO4 and on their catalytic properties in selective H2S oxidation to sulfur was studied. With the use of thermal analysis, XPS, and Moessbauer spectros- copy, it was found that an X-ray amorphous iron-containing compound of complex composition was formed on the catalyst surface after thermal treatment in the temperature range of 400-500°C. This compound contained Fe3+ cations in three nonequivalent positions characteristic of various oxy and hydroxy sulfates and oxide and sulfate groups as anions. Calcination at 600°C led to the almost complete removal of sulfate groups; as a result, the formation of an oxide structure came into play, and it was completed by the production of finely dispersed iron oxide in the ε-Fe2O3 modification (the average particle size of 3.2 nm) after treatment at 900°C. As the calcination temperature was increased from 500 to 700°C, an increase in the catalyst activity in hydrogen sulfide selective oxidation was observed because of a change in the state of the active component. A comparative study of the samples by temperature-programmed sulfidation made it possible to establish that an increase in the calcination temperature leads to an increase in the stability of the iron-containing catalysts to the action of a reaction atmosphere. Pleiades Publishing, Ltd., 2011.
- Shuvaeva,Delii,Mart'yanov,Bayukov,Osetrov,Saraev,Kaichev,Sakaeva,Bukhtiyarova
-
p. 896 - 906
(2012/05/20)
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- Kinetics of iron-copper sulphides oxidation in relation to protohistoric copper smelting
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This article deals with one specific step of the copper extractive metallurgy process: the roasting of iron-copper sulphides. It aims at shedding light on an archaeological issue: the reconstruction of the copper extractive metallurgy processes during protohistory (IVe-IIe millennium BC). Experimental simulations are performed at laboratory scale by modelizing the conditions of protohistoric furnaces. Kinetic of roasting is studied by thermogravimetry combined with the physico-chemical analysis of synthetic products. The influence of two parameters is studied: (i) the temperature (773, 973 and 1173 K) and (ii) the granularity of the roasted ores (1 mm and 100 μm). In each case, the chemical mechanism governing the oxidation of iron copper sulphide is proposed. Apart from one extreme case (= 1 mm; T = 773 K), it is showed that kinetic is controlled by the transport of molecular oxygen (O2) from the gas to the grain surface. Moreover, we prove that, in some cases where the diffusivity of gaseous oxygen is low, roasting can be accelerated by the presence of an oxide, which constitute an in-situ source of oxygen. Theses experiments support the hypothesis that such a technique could have allowed a roasting process where iron and sulfur were removed by the solid oxygen instead of the gaseous oxygen. These results allow to validate a one-step copper smelting process starting from sulphidic ores, and to identify the experimental parameters of this process.
- Burger, Emilien,Bourgarit, David,Frotte, Vincent,Pilon, Fabien
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p. 249 - 256
(2011/06/18)
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- PROCESS FOR PRODUCING METHYL CHLORIDE AND SULFUR DIOXIDE
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Produce methyl chloride and sulfur dioxide using a reactor with lanthanum oxychloride, and contacting the lanthanum oxychloride with methanesulfonyl chloride under conditions sufficient to convert a portion of the methanesulfonyl chloride to methyl chloride and sulfur dioxide.
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Page/Page column 2; 3
(2011/10/03)
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- Cationic and radical intermediates in the acid photorelease from aryl sulfonates and phosphates
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The irradiation of a series of phenyl sulfonates and phosphates leads to the quantitative release of acidity with a reasonable quantum yield (≈0.2). Products characterization, ion chromatography analysis and potentiometric titration are consistent with the intervening of two different paths in this reaction, viz. cationic with phosphates and (mainly) radical with sulfonates. The Royal Society of Chemistry and Owner Societies 2011.
- Terpolilli, Marco,Merli, Daniele,Protti, Stefano,Dichiarante, Valentina,Fagnoni, Maurizio,Albini, Angelo
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experimental part
p. 123 - 127
(2012/01/03)
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- Hydrogen sulfide oxidation by ozone on sorbents-catalysts
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Effect of the sorbents SK-2001, SK-2002, SK-1138, SK-498, SK-8, SK-174, SK-57, SK-458, SK-455, SK-19, and SK-72 based on a KhIPEK synthetic ceramics on the oxidation of hydrogen sulfide by ozone was studied. The sorbents that catalyze the reaction of hydrogen sulfide oxidation by ozone were determined.
- Aleksandrov, Yu. A.,Belyaev,Sozin, A. Yu.,Churbanov
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p. 1548 - 1552
(2011/02/16)
-
- Effect of N atoms in the backbone of metal phthalocyanine derivatives on their catalytic activity to lithium battery
-
Metal phthalocyanine (MPc, M = Mn2+, Fe2+, Co2+, Ni2+ and Cu2+), metal tetrapyridinoporphyrazine, and metal tetrapyrazinoporphyrazine are synthesized by microwave reaction and characterized by elemental analyzer, IR spectroscopy and UV-vis spectroscopy. The catalytic activity of MPc derivatives to Li/SOCl2 battery is evaluated by the relative discharge energy of the battery whose electrolyte contains the compounds. The discharge energy of Li/SOCl2 battery catalyzed by MPc is approximately 0-61% higher than that of Li/SOCl2 battery in the absence of compounds, depending on the central metal ion. To the same central metal ion, the discharge energy of Li/SOCl2 battery catalyzed by MTAP is approximately 60% higher than that by MPc. The discharge energy of Li/SOCl2 battery in which SOCl2 contains MPTpz is approximately 17-19% higher than that of the battery in the absence of compounds, and almost independent of central metal ions. It shows a correlation existing between the structure and the catalytic active sites of MPc derivatives. The double active site model is proposed to interpret the results.
- Xu, Zhanwei,Zhang, Guoxiang,Cao, Zeyuan,Zhao, Jianshe,Li, Hejun
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p. 101 - 105
(2010/06/16)
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- CONTINUOUS PROCESS FOR CONVERTING NATURAL GAS TO LIQUID HYDROCARBONS
-
A method comprising: providing a first halogen stream; providing a first alkane stream; reacting at least a portion of the first halogen stream with at least a portion of the first alkane stream in a first reaction vessel to form a first halogenated stream; providing a second alkane stream comprising C2 and higher hydrocarbons; providing a second halogen stream; and reacting at least a portion of the second halogen stream with at least a portion of the second alkane stream in a second reaction vessel to form a second halogenated stream.
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Page/Page column 67-68
(2010/04/03)
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