- A magnetically retrievable heterogeneous copper nanocatalyst for the synthesis of 5-substituted tetrazoles and oxidation reactions
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Abstract: A copper complex anchored on functionalized Fe3O4 nanoparticles was prepared by a simple and inexpensive procedure using commercially available materials. The prepared catalyst was characterized by a range of physical and spectroscopic techniques. Ease of operation, high efficiency, eco-friendly procedure, easy separation of the catalyst and reusability for several consecutive runs without significant loss of its activity are several advantages of this catalyst. The catalytic activity has been explored for the oxidation of sulfides, oxidative coupling of thiols and synthesis of 5-substituted tetrazoles. Graphical Abstract: A magnetically retrievable heterogeneous copper nanocatalyst for the synthesis of 5-substituted tetrazoles and oxidation reactions[Figure not available: see fulltext.].
- Darabi, Mitra,Tamoradi, Taiebeh,Ghadermazi, Mohammad,Ghorbani-Choghamarani, Arash
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- Facile hydrolysis-based chemical destruction of the warfare agents VX, GB, and HD by alumina-supported fluoride reagents
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(Chemical Equation Presented) A facile solvent-free hydrolysis (chemical destruction) of the warfare agents VX (O-ethyl S-2-(diisopropylamino)ethyl methylphosphonothioate), GB (O-isopropyl methylphosphonofluoridate or sarin), and HD (2,2′-dichloroethyl sulfide or sulfur mustard) upon reaction with various solid-supported fluoride reagents is described. These solid reagents include different alumina-based powders such as KF/Al2O3, AgF/KF/Al2O3, and KF/Al2O3 enriched by so-called coordinatively unsaturated fluoride ions (termed by us as ECUF-KF/Al2O3). When adsorbed on these sorbents, the nerve agent VX quickly hydrolyzed (t1/2 range between 0.1-6.3 h) to the corresponding nontoxic phosphonic acid EMPA as a major product (>90%) and to the relatively toxic desethyl-VX (1/2 range between 2.2-161 h). The reaction rates and the product distribution were found to be strongly dependent on the nature of the fluoride ions in the KF/Al2O 3 matrix and on its water content. All variations of the alumina-supported fluoride reagents studied caused an immediate hydrolysis of the highly toxic GB (t1/2 31P, 13C, and 19F MAS NMR.
- Gershonov,Columbus,Zafrani
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- Synthesis of macroscopic monolithic metal-organic gels for ultra-fast destruction of chemical warfare agents
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The potential threat that has originated from chemical warfare agents (CWAs) has promoted the development of advanced materials to enhance the protection of civilian and military personnel. Zr-based metal-organic frameworks (Zr-MOFs) have recently been demonstrated as excellent catalysts for decomposing CWAs, but challenges of integrating the microcrystalline powders of Zr-MOFs into monoliths still remain. Herein, we report hierarchically porous monolithic UiO-66-X xerogels for the destruction of CWAs. We found that the UiO-66-NH2xerogel with a larger pore size and a higher surface area than the UiO-66-NH2powder possessed better degradability of 2-chloroethyl ethyl sulfide (2-CEES), which is a sulfur mustard simulant. These UiO-66-X xerogels exhibit outstanding performance for decomposing CWAs. The half-lives of vesicant agent sulfur mustard (HD) and nerve agentO-ethylS-[2-(diisopropylamino)ethyl] methylphosphonothioate (VX) are as short as 14.4 min and 1.5 min, respectively. This work is, to the best of our knowledge, the first report on macroscopic monolithic UiO-66-X xerogels for ultrafast decomposition of CWAs.
- Li, Heguo,Pan, Hongjie,Tao, Cheng-An,Wang, Lingyun,Yang, Guang,Zhang, Shouxin,Zhou, Chuan
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- Metal ferrite nanoparticles: Synthesis, characterization, and studies on decontamination of sulfur mustard
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Mg, Ca, Mn, Co, Ni, Cu, Zn, Mn-Zn, and Co-Zn metal ferrite and mixed metal ferrite nanoparticles were synthesized by co-precipitation method and were characterized by using transmission electron microscopy, X-ray diffraction, and nitrogen adsorption techn
- Praveen Kumar,Prasad,Ramacharyulu,Singh, Beer,Anchal Roy
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- La complex supported on magnetic nanoparticles: green, efficient, novel and reusable nanocatalyst for the synthesis of 5-substituted tetrazoles and the oxidation reactions in neat condition
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In the present work, we were interested in the synthesis of green and novel magnetic nanocatalyst by anchoring La complex on Fe3O4. The nanocatalyst was successfully synthesized and characterized by FT-IR, SEM, TGA, XRD, EDX, and ICP techniques. The designed procedure shows many benefits such as short reaction time, high yield, excellent purity, eco-friendly catalyst, easy workup and easy recovery from the reaction mixture by external magnet. [Figure not available: see fulltext.].
- Tamoradi, Taiebeh,Irandoust, Asrin,Ghadermazi, Mohammad
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- A mechanism of alkali metal carbonates catalysing the synthesis of β-hydroxyethyl sulfide with mercaptan and ethylene carbonate
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The reaction of β-hydroxyethylation is essential to the current practice of organic chemistry. Here, we proposed a new and green route to synthesize 2-hydroxyethyl n-alkyl sulfide with n-alkyl mercaptan and ethylene carbonate (EC) in the presence of alkali carbonates as catalysts and revealed the mechanism by experiments and theoretical calculations. The reaction reported proceeds rapidly with high yields when it is performed at 120 °C and the catalytic loading is ~1 mol%. This protocol is applicable to other mercaptans to synthesize the corresponding β-hydroxyethyl sulfide. Density functional theory-based calculations show the energy profile for the reaction pathway. The rate-determining step is the ring-opening of EC. A negatively charged O atom of alkali carbonates approaches the S atom of -SH under the influence of hydrogen bonds. An activated S atom that carries more negative charge serves as a nucleophilic reagent and assists in the ring-opening of EC by reducing the Mayer bond orders of the C1-O1 bond in EC. Alkali cations also contribute to the C1-O1 bond cleavage. The energy barrier for the ring-opening of EC decreases with the decrease of electronegativity of alkali cations. Subsequent transference of a H atom leads to the formation of β-hydroxyethyl sulfide, the dissociation of CO2 and the reduction of K2CO3
- Liu, Dongliang,Thomas, Tiju,Gong, Hong,Li, Fei,Li, Qiang,Song, Lijuan,Azhagan, Tamil,Jiang, Heng,Yang, Minghui
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- Kinetics and Mechanism of the Oxidation of 2-Mercaptoethanol by Hydrogen Peroxide in Aqueous Solution
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The kinetics of oxidation of 2-mercaptoethanol by H2O2 to 2-hydroxethyl disulfide in aqueous solution has been studied.Over the pH range 9 to 13, the rate law for the oxidation of 2-mercaptoethanol was found to be where R is HOC2H4, K' is the apparent acid dissociation constant of H2O2, K'a1 and K'a2 are the apparent acid dissociation constants of HOC2H4SH and HOC2H4S-, respectively, and aH+ is the hydrogen ion activity.A nonlinear least-squares fit of experimental data to the above rate law gave values of k1 = 12.64 +/- 0.54 M-1 s-1 and k2 = 0.93 +/- 0.39 M-1 s-1 at 20 deg C.The rate law and other data indicate that the reaction proceeds via a nucleophilic displacement by thioethanol on hydrogen peroxide with the formation of HOCH2CH2SOH as a intermediate.
- Leung, Ping-Sang K.,Hoffmann, Michael R.
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- Zirconium oxide complex-functionalized MCM-41 nanostructure: An efficient and reusable mesoporous catalyst for oxidation of sulfides and oxidative coupling of thiols using hydrogen peroxide
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Zirconium oxide complex-functionalized mesoporous MCM-41 (Zr-oxide@MCM-41) as an efficient and reusable catalyst is reported for the oxidation of sulfides into sulfoxides using hydrogen peroxide (H2O2) as the oxidant, with short reaction times in good to excellent yields at room temperature under solvent-free conditions. Also, a simple and efficient method is reported for the oxidative coupling of thiols into corresponding disulfides in good to high yields using H2O2 as oxidant in the presence of Zr-oxide@MCM-41 as recoverable catalyst in ethanol at room temperature. A series of sulfides and thiols possessing functional groups was successfully converted into corresponding products. After completion of reactions the catalyst was easily separated with simple filtration from the reaction mixture and reused for several consecutive runs without significant loss of catalytic efficiency. The mesoporous catalyst was characterized using Fourier transform infrared spectroscopy, Brunauer-Emmett-Teller surface area measurements, X-ray diffraction, transmission and scanning electron microscopies, energy-dispersive X-ray spectroscopy and thermogravimetric analysis.
- Hajjami, Maryam,Shiri, Lotfi,Jahanbakhshi, Azar
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- A dual-function all-inorganic intercluster salt comprising the polycation ?-[Al13O4(OH)24(H2O)12]7+and polyanion α-[PMo10V2O40]5-for detoxifying sulfur mustard and soman
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?-[Al13O4(OH)24(H2O)12]7+, which shares similarity with the phosphotriesterase active site ZnII-OH-ZnII, was specially chosen to interact with the cluster α-PMo10V2O405- to form a new three-dimensional intercluster, which crystallized in the monoclinic space group P21/m with Z = 2, for the decontamination of chemical warfare agents. The experimental results showed that 50 mg of the compound decontaminated 96.4percent (within 120 min) and 99.5percent (within 40 min) of sulfur mustard (HD) (4 μL) and soman (GD) (4 μL), respectively, in ambient conditions. The decontamination processes followed first-order reaction kinetics with a rate constant and half-life of 0.01234 min-1 and 56.15 min for HD and 0.1198 min-1 and 5.78 min for GD, respectively. It was concluded that the α-PMo10V2O405- moiety was responsible for the catalytic oxidation of HD into non-toxic sulfoxide, while the ?-[Al13O4(OH)24(H2O)12]7+ moiety was responsible for the catalytic hydrolysis of HD and GD into nontoxic hydrolysates. Besides, the compound showed notable efficacy for the decontamination of HD on guinea pig skin and of GD on Kunming mouse skin, indicating high potential for use in human skin protection and treatment. This journal is
- Gao, Qi,Tao, Fangsheng,Wang, Yong'An,Yin, Jianbo,Yu, Jialin,Zhang, Lijuan,Zhong, Yuxu,Zhou, Yuanyuan,Zhou, Yunshan
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supporting information
p. 8122 - 8135
(2020/07/10)
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- Highly efficient, green, rapid, and chemoselective oxidation of sulfur-containing compounds in the presence of an MCM-41@creatinine@M (M = la and Pr) mesostructured catalyst under neat conditions
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In the present study, we report the synthesis of two green recoverable catalysts by covalent linking of the creatinine La and Pr complexes on an MCM-41 mesostructure with the commercially available materials and via a simple and inexpensive procedure. These heterogeneous catalysts were characterized by Fourier transform infrared spectroscopy, energy-dispersive X-ray spectroscopy, scanning electron microscopy, N2 adsorption and desorption, inductively coupled plasma optical emission spectroscopy, and thermogravimetric analysis. The obtained mesostructures act as active and reusable catalysts for the oxidation of sulfides and oxidative coupling of thiols under neat conditions. More importantly, significant practical advantages of this environmentally friendly process include high efficiency, good reaction times, and convenient recovery and reusability for several times without any significant loss of activity of the catalyst.
- Tamoradi, Taiebeh,Ghadermazi, Mohammad,Ghorbani-Choghamarani, Arash
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p. 5479 - 5488
(2018/03/30)
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- Degradation of Sulfur Mustard on KF/Al2O3: The Role of Organic Solvents and Active Species
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Solvent effects on the ability of KF/Al2O3 supports to degrade the warfare agent sulfur mustard (HD) were explored. RP-KF/Al2O3 possessing hydroxide ions and ECUF/KF/Al2O3 holding fluoride
- Fridkin, Gil,Columbus, Ishay,Yehezkel, Lea,Zafrani, Yossi
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p. 10541 - 10545
(2018/07/25)
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- Method for continuously synthesizing thiodiglycol
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The invention discloses a method for continuously synthesizing thiodiglycol. The method is based on a tubular reactor, ethylene oxide and sulfureted hydrogen serve as raw materials, the reaction is performed at 0-40 DEG C, and thiodiglycol is synthesized by liquid phase catalysis at normal temperature and normal pressure. The operation is simple, the conditions are mild, the method is green, environmentally friendly and free of three wastes, and a catalyst can be reused; the reaction standing time is short, no back-mixing occurs, no by-product is generated, slightly excessive ethylene oxide can be recycled, the production cycle is shortened, and the production cost is reduced. The tubular reactor can react continuously, the product purity can reach 98-99.5%, and the yield of thiodiglycol can reach 92-99% according to hydrogen sulfide.
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Paragraph 0025-0027
(2017/02/23)
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- Kinetic studies on oxidation of l-cysteine and 2-mercaptoethanol by a trinuclear Mn(IV) species in aqueous acidic media
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In aqueous media, the trinuclear MnIV complex, [Mn IV3(μ-O)4(phen)4(H 2O)2]4+ (phen = 1,10-phenanthroline) (1) behaves like a monobasic acid, equilibrates with its deprotonated conjugate base (2) (12 + H+, pKa = 4.00 (± 0.15) at 25.0 °C, I = 1.0 M, maintained with NaNO3). An aqueous solution of 1 in the pH range 2.2-4.0 smoothly oxidizes 2-mercaptoethanol (mercap) and l-cysteine (cys) to their respective disulfides; itself being reduced to [Mn(phen) 3]2+ in presence of excess 1,10-phenanthroline which also masks Cu2+, if any, present in the reaction media as impurity as well as acting as a buffer that controls pH range during the reaction. The observed rate constants in H2O media were found to be considerably lowered in media enriched with D2O and a proton-coupled single electron transfer rate step is proposed. Interestingly, we found that deprotonated oxidant (2) reacts faster than the protonated species (1) in oxidizing both the thiols.
- Chakraborty, Maharudra,Mandal, Pulak Chandra,Mukhopadhyay, Subrata
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- Rapid monitoring of sulfur mustard degradation in solution by headspace solid-phase microextraction sampling and gas chromatography mass spectrometry
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A method using headspace solid-phase microextraction (HS-SPME) followed by gas chromatography/ mass spectrometry (GC/MS) analysis has been developed to gain insight into the degradation of the chemical warfare agent sulfur mustard in solution. Specifically, the described approach simplifies the sample preparation for GC/MS analysis to provide a rapid determination of changes in sulfur mustard abundance. These results were found to be consistent with those obtained using liquid-liquid extraction (LLE) GC/MS. The utility of the described approach was further demonstrated by the investigation of the degradation process in a complex matrix with surfactant added to assist solvation of sulfur mustard.Amore rapid reduction in sulfur mustard abundance was observed using the HS-SPME approach with surfactant present and was similar to results from LLE experiments. Significantly, this study demonstrates that HS-SPME can simplify the sample preparation for GC/MS analysis to monitor changes in sulfur mustard abundance in solution more rapidly, and with less solvent and reagent usage than LLE. Copyright
- Creek, Jo-Anne M.,McAnoy, Andrew M.,Brinkworth, Craig S.
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body text
p. 3419 - 3424
(2012/01/03)
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- Locus-specific microemulsion catalysts for sulfur mustard (HD) chemical warfare agent decontamination
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The rates of catalytic oxidative decontamination of the chemical warfare agent (CWA) sulfur mustard (HD, bis(2-chlororethyl) sulfide) and a range (chloroethyl) sulfide simulants of variable lipophilicity have been examined using a hydrogen peroxide-based microemulsion system. SANS (small-angle neutron scattering), SAXS (small-angle X-ray scattering), PGSE-NMR (pulsed-gradient spin-echo NMR), fluorescence quenching, and electrospray mass spectroscopy (ESI-MS) were implemented to examine the distribution of HD, its simulants, and their oxidation/hydrolysis products in a model oil-in-water microemulsion. These measurements not only present a means of interpreting decontamination rates but also a rationale for the design of oxidation catalysts for these toxic materials. Here we show that by localizing manganese-Schiff base catalysts at the oil droplet-water interface or within the droplet core, a range of (chloroethyl) sulfides, including HD, spanning some 7 orders of octanol-water partition coefficient (Kow), may be oxidized with equal efficacy using dilute (5 wt. % of aqueous phase) hydrogen peroxide as a noncorrosive, environmentally benign oxidant (e.g., t1/2 (HD) ~ 18 s, (2-chloroethyl phenyl sulfide, C6H5SCH2CH 2Cl) ~ 15 s, (thiodiglycol, S(CH2CH 2OH)2) ~ 19 s {20°C}). Our observations demonstrate that by programming catalyst lipophilicity to colocalize catalyst and substrate, the inherent compartmentalization of the microemulsion can be exploited to achieve enhanced rates of reaction or to exert control over product selectivity. A combination of SANS, ESI-MS and fluorescence quenching measurements indicate that the enhanced catalytic activity is due to the locus of the catalyst and not a result of partial hydrolysis of the substrate.
- Fallis, Ian A.,Griffiths, Peter C.,Cosgrove, Terence,Dreiss, Cecile A.,Govan, Norman,Heenan, Richard K.,Holden, Ian,Jenkins, Robert L.,Mitchell, Stephen J.,Notman, Stuart,Platts, Jamie A.,Riches, James,Tatchell, Thomas
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supporting information; scheme or table
p. 9746 - 9755
(2011/03/20)
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- Degradation of sulfur mustard on KF/Al2O3 supports: Insights into the products and the reactions mechanisms
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(Chemical Equation Presented) The degradation of the warfare agent sulfur mustard (HD) adsorbed onto KF/Al2O3 sorbents is described. These processes were explored by MAS NMR, using 13C-labeled sulfur mustard (HD*) and LC-M
- Zafrani, Yossi,Goldvaser, Michael,Dagan, Shai,Feldberg, Liron,Mizrahi, Dana,Waysbort, Daniel,Gershonov, Eytan,Columbus, Ishay
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p. 8464 - 8467
(2010/02/28)
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- 6-THIO-SUBSTITUTED PACLITAXELS
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The present invention concerns novel paclitaxel derivatives, their use as antitumor agents, and pharmaceutical formulations.
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- 6-thio-substituted paclitaxels
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The present invention concerns novel paclitaxel derivatives, their use as antitumor agents, and pharmaceutical formulations.
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- Process for the preparation of polyalkyl-1-oxa-diazaspirodecane compounds
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The invention relates to a process for the preparation of polyalkyl-1-oxa-diazaspirodecane compounds, which can be used as highly active light stabilizers for polymers. The reaction is carried out in a solvent mixture of at least one alcohol and if appropriate an inert organic solvent in the presence of solid alkali metal hydroxide or a corresponding amount of a mixture of solid alkali metal hydroxide and water as the sole catalyst. The process offers the advantage that, by using a solvent mixture and dispensing with a phase transfer catalyst, a higher rate of reaction and therefore higher product quality with the same yield are achieved. By dispensing with a phase transfer catalyst, which remains in the waste water and must be disposed of expensively, and by the reusability of the solvent mixture, the process is more environment-friendly and more economical than processes known to date.
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- Solid phase synthesis of peptides containing a phosphoserine - Sulfur mustard adduct
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Solid phase synthesis of peptides containing a serine thiodiglycol phosphate residue has been achieved by following a global on-resin phosphorylation strategy with a functionalized benzyl phosphoramidite. To preclude cleavage of the acid labile thiodiglycol phosphate ester during deprotection, the thioether functionality was temporarily protected as a sulfoxide.
- Noort,Platenburg,Benschop
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p. 2007 - 2012
(2007/10/03)
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- The Hydrolysis of Bis(2-chloroethyl) Sulfide (Sulfur Mustard) in Aqueous Mixtures of Ethanol, Acetone and Dimethyl Sulfoxide
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The rate of hydrolysis of bis(2-chloroethyl) sulfide (sulfur mustard) in aqueous mixtures of ethanol, acetone and dimethyl sulfoxide has been measured and compared with previously reported values.Rate constants in water at 25 deg C for the two consecutive hydrolysis reactions undergone by sulfur mustard were estimated to be (2.93 +/- 0.15)*10-3 and (3.87 +/- 0.14)*10-3 s-1.Charge separation of 0.42 in the transition states was indicated together with significant solvation of the positive end of the transition state dipoles.
- Tilley, R. Ian
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p. 293 - 300
(2007/10/02)
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- THE CHARACTERIZATION OF SULFONIUM CHLORIDES BY GAS CHROMATOGRAPHY/MASS SPCTROMETRY AND THE DEGRADATION OF 2-CHLOROETHYL SULFIDE DERIVATIVES
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Three aqueous samples containing sulfonium chloride salts of both mustard gas (2,2'-dichlorodiethylsulfide) and its simulant 2-chloroethyl ethyl sulfide have been characterized by gas chromatography/mass spectrometry (GC/MS).Theese salts decompose thermallly to the sorresponding 2-chloroethyl and 2-hydroxyethyl sulfides, therefore GC/MS analysis is not indicative of the true composition of these solutions.Small amounts of dithioethers characteristic of the decomposition of the dimeric salts were also detected.Electron Impact (EI) ionization produces a more intense molecular ion than methane chemical ionization (CI) for the dithioethers because of the ease of formation of sulfonium ions during chemical ionization.The composition products of four aged samples of 2-chloroethyl sulfides (RSCH2CH2Cl where R=methyl, ethyl, phenyl and benzyl groups) were also characterized by GC/MS, which indicated that decomposition of these compounds may proceed via dimeric sulfonium ions.Mustard gas was detected in all but one of the samples, providing evidence for secondary sulfonium cation formation in the degradation prcess.Keywords: Sulfonium chlorides; 2-chloroethyl sulfides; degradation; dimeric sulfonium cations; GC/MS characterization.
- Rourhbaugh, Dennis K.,Yang, Yu-Chu,Ward, J. Richard
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- Triazenes as Transport Form of Sulfur Mustard: Synthesis of 3-aryltriazenes and Study of Their Reactions in Aqueous and Nonaqueous Solutions
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A group of biologically active 1-aryl-3-triazenes has been synthesized.The rates of decomposition of a selected triazene, determined polarographically, increase with decrease in pH from 7.1 to 5.1.The products of aqueous decomposition have been analyzed by GC and GC-MS.A selectively deuterated triazene is found helpful in discriminating between alternative decomposition pathways.The data are consistend with initial protonation of the triazene and generation therefrom of a S-(2-chloroethyl)thioethyl cation (or its kinetic equivalent) which undergoes rearrangements as detected by deuterium scrambling.A second competing pathway may involve cyclization of the triazene to a 1-aryl-1,2,3-triazathiaoctene intermediate which then undergoes nucleophilic opening with attendant loss of nitrogen.These triazenes readily esterify 3,5-dinitrobenzoic acid and diethyl phosphate in etheral solutions.The use of deuterium labelled triazene indicates that these triazenes esterify predominantly via ion-pair mechanism and SN2 displacement is the minor pathway.A selected triazene is observed to alkylate the N3-position of triacetyluridine, also via a combination of ion-pair and SN2 displacement mechanisms as studied by the application of deuterium labelling.These studies are expected to assist in the interpretation of the cytotoxic effects of these triazenes.
- Singh, Ranjit
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p. 1088 - 1097
(2007/10/02)
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- Cyclic phosphorous acid esters
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Phosphorous acid esters obtained by reacting bisphenols with phosphorous trihalogenide or triphosphite and optionally or mono - or polyhydroxy compound are especially useful for stabilizing polyamides.
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