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1.
A.A. Viggiano Susan T. Arnold Skip Williams Thomas M. Miller 《Plasma Chemistry and Plasma Processing》2002,22(2):285-295
Rate constants and product branching ratios were measured for eleven sulfur oxide, sulfur fluoride, and sulfur oxyfluoride anions reacting with O3. The SO–
2 ion reacts rapidly to form –O–
3, SO–
3, and e–. The temperature dependence of the branching ratio shows more reactive detachment and less SO–
3 formation at higher temperature. SO–
3 reacts with O3, forming SO–
4 at 1/3 to 1/4 of the collisional rate from 200 to 500 K, respectively. At 300 K, SF–
6 charge transfers to O3 at 20% of the collisional rate. F2SO–
2 reacts with O3 at a few percent of the collision rate, forming both O–
3 and FSO–
3; The ion F3SO– reacts slowly with O3 to form F3SO–
2. The ions SO–
4, SF–
5, FSO–
2, FSO–
3, F3SO–, and F5SO– are unreactive with O3. A trend is noted relating the ion reactivity with the coordination of the central sulfur atom, i.e., the number of S–F bonds plus two times the number of S=O bonds. Only ions with a sulfur coordination of 4 or 6 are reactive, although the reaction rate constants are generally small. The reactivity trends appear to be partially explained by spin conservation. These reactions are all sufficiently slow, so O3 reactions should not play a major role in SF6/O2 discharges. All ions studied have been found to be unreactive with O2. 相似文献
2.
Conclusions A method has been developed for the preparation of methylthiocyclopropanedicarboxylic acid derivatives based on reactions of azomethines with dimethylcarboethoxymethylidenesulfurane, which is generatedin situ from its sulfonium salt precursor and KOH in the presence of a phase transfer catalyst.Translated from Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, No. 4, pp. 828–833, April, 1988. 相似文献
3.
V. K. Mavrodiev I. I. Furlei S. N. Lakeev F. Z. Galin G. A. Tolstikov 《Russian Chemical Bulletin》1999,48(11):2077-2079
The mass spectra of negative ions of keto-stabilized sulfur and phosphorus ylides (obtained from amino acids) and products
of their thermal conversion are studied. The most characteristic peaks in the mass spectra of ylides belong to negative molecular
ions and to [M−H]− ions. Peaks of fragment ions in the mass spectra of ylides and products of their thermal conversion coincide both in mass
numbers and resonance energies.
For Part 8, see Ref. 1.
Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 11, pp. 2100–2103, November, 1999. 相似文献
4.
A keto-stabilized sulfur ylide, containing phthalazinedione fragment, was synthesized. During thermolysis, the ylide forms
the product of intramolecular cyclization of pyrrolophthalazinedione structure.
Published in Russian in Izvestiya Akademii Nauk. Seriya Khimicheskaya, No. 11, pp. 2227–2229, November, 2007. 相似文献
5.
使用二次组态相互作用(QCISD)方法和6-311G(d),6-311+G(d),6-311G(2d) 及6-311+G(2d)基组研究了SO2^-和SO3^-的分子结构,超精细偶数常数(hfcc)及 其对应的分子的绝热电子亲合势(AEA)。发现在QCISD/6-311+G(2d)水平上计 算的两个分子离子的结构,hfcc值(在^33S和^17O上的)和AEA值与实验值符合得 都很好(除SO^3-中的在^33S上的hfcc值比实验值小23%)。作为比较,我们使用 相同基组作了B3LYP方法计算,得到的超精细偶合常数和AEA值却都与实验符合得不 好。 相似文献
6.
1. | 1,2-Oxathiolan-5-one-2-oxides are readily cleaved by nucleophiles (H2O, ROH, HNR2) under mild conditions at the O-CO bond only, with the formation of the -(hydroxysulfinyl)-alkanoic acid derivatives. |
2. | 2,1-Benzoxathiol-3-one-1-oxide is cleaved by alcohols at both the O-CO and the O-SO bonds to give the unstable monoesters at the carboxyl and sulfinyl groups. |
3. | Unlike 2,1-benzoxathiol-3-one-1-oxide, 1,2-oxathiolan-5-one-2-oxides on boiling with excess alcohols give -(hydroxysulfinyl)alkanoic acid bisesters. |
7.
8.
9.
A gas chromatographic system for the simultaneous acquisition of hydrocarbon and sulfur chromatograms was developed. Detection of sulfur compounds is achieved using a sulfur chemiluminescence detector (SCD) mounted in series with a flame ionization detector (FID). A constant fraction of the effluent of the FID is transferred to the SCD by means of a fixed restrictor. Unlike previous versions of this approach, the FID is not used to generate the chemiluminescent sulfur species. Rather, the FID is operated under optimum conditions for hydrocarbon analysis and a furnace is used to generate the chemiluminescent sulfur species. The system permits dual acquisition of the hydrocarbon and sulfur signals in a single analysis with a single column, since the detectors are operated in a serial fashion. The application of sulfur simulated distillation using this approach was examined, since this requires simultaneous universal and sulfur selective detection. Precision of absolute response of both the FID and SCD was typically less than 2% RSD for a standard reference material. 相似文献
10.
Aishik Bhattacharya Arnab Kumar Nath Arnab Ghatak Abhijit Nayek Souvik Dinda Rajat Saha Somdatta Ghosh Dey Abhishek Dey 《Angewandte Chemie (International ed. in English)》2023,62(10):e202215235
The reduction of SO2 to fixed forms of sulfur can address the growing concerns regarding its detrimental effect on health and the environment as well as enable its valorization into valuable chemicals. The naturally occurring heme enzyme sulfite reductase (SiR) is known to reduce SO2 to H2S and is an integral part of the global sulfur cycle. However, its action has not yet been mimicked in artificial systems outside of the protein matrix even after several decades of structural elucidation of the enzyme. While the coordination of SO2 to transition metals is documented, its reduction using molecular catalysts has remained elusive. Herein reduction of SO2 by iron(II) tetraphenylporphyrin is demonstrated. A combination of spectroscopic data backed up by theoretical calculations indicate that FeIITPP reduces SO2 by 2e−/2H+ to form an intermediate [FeIII−SO]+ species, also proposed for SiR, which releases SO. The SO obtained from the chemical reduction of SO2 could be evidenced in the form of a cheletropic adduct of butadiene resulting in an organic sulfoxide. 相似文献
11.
In the anionic copolymerization of elemental sulfur (S8) with propylene sulfide (P) below the floor temperature of elemental sulfur homopolymerization (Tf = 159°C), there is a certain concentration of elemental sulfur left when copolymerization is completed ([S8]eq). The dependence of [S8]eq on the feed ratio [P]0/[S8]0 and temperature was determined by using laser Raman spectroscopy, and this enabled us to distinguish between the S-S bonds in elemental sulfur and in the linear polysulfide. [S8]eq was found to decrease with increasing temperature and with an increasing [P0]/[S8]0 ratio. The experimental dependence of the average enthalpy and entropy of polymerization (δ[Hbar][Xbar], and δ [Sbar][Xbar]) on [Xbar], as described by the equilibrium …-CH2CH(CH3)SX ? + S8 = …-CH2CH(CH3)SX+8 ?, has shown that at [Xbar] ?; 9 the experimental δ[Hbar][Xbar] and δ [Sbar][Xbar] approach values determined earlier for the free radical homopolymerization of elemental sulfur …-Sn ? + S8 ≤ …-S? n+8&; The corresponding values are 3.1 kcal/mol and 4.76 cal/mol · degree. 相似文献
12.
用氧瓶燃烧-电位滴定法测定煤中有机硫和橡胶总硫 总被引:1,自引:0,他引:1
研究了煤中有机硫和橡胶中总硫的微量测定方法,样品经氧瓶分解后所转变的SO42-在Fe(CN)63-/Fe(CN)64-电对存在下用Pb2+滴定。提出了采用Zn3[Fe(CN)6]2、微酸性溶液和低浓度Fe(CN)64-存在下,消除磷干扰的新方法,应用于合成样品和实际样品的分析,结果满意。其回收率>98%,相对标准偏差<2.3%,绝对误差<0.15%。 相似文献
13.
本文将三类粘结剂体系(PVDF、LA133和CMC+SBR)用于构筑锂硫电池硫正极,表征了不同粘结剂材料的官能团结构、结晶性能、热力学性质、电解液吸收性与粘结强度,考察了粘结剂种类对电极电化学性能的影响。结果表明,由1∶1质量比的CMC+SBR制作的硫电极吸液率低,剥离强度低,循环稳定性较差;无定形LA133支持高的粘结强度,维稳电极结构的能力强;PVDF因半结晶状态制约粘结效果,制作的电极吸液量高,但电荷转移阻抗小。基于PVDF制作的硫正极具有相对最优的电化学性能,其0.2C下循环100周后保留的可逆容量达722mAh·g~(-1),容量保持率达82.9%。 相似文献
14.
高频红外碳硫分析仪测定石膏矿中的三氧化硫 总被引:1,自引:0,他引:1
王娜 《分析测试技术与仪器》2017,23(2):120-123
利用高频红外碳硫仪对石膏矿中三氧化硫含量的测定进行了研究,取得了较好的结果.方法检出限为0.003 0%.用石膏标准样品(GBW03109a,GBW03110)进行分析,测定值与认定值相符,测定值的相对标准偏差(n=9)在0.32%~0.81%之间.使用石膏标准样品(GBW03111)进行本法与国标硫酸钡重量法做比对试验,测定结果无显著性差异.加标回收率为96.4%~104.0%. 相似文献
15.
B. Zwanenburg H.J.F. Philipse M.M.H. Verstappen R.G. Gieling 《Phosphorus, sulfur, and silicon and the related elements》2013,188(1):453-454
The synthesis of epoxy sulfines and sulfonyl azirines is described 相似文献
16.
17.
Wolfgang Bauer 《Phosphorus, sulfur, and silicon and the related elements》2013,188(1-4):493-494
Abstract A general method to reduce arene sulfonylchlorides to diarene disulfanes has been developped using sulfur dioxide and hydroiodic acid/quarternary ammonium salts as catalysts in a two - phase system. 相似文献
18.
《Analytical letters》2012,45(6):465-471
Abstract An automatic sulfur titrator paired with a high-frequency induction furnace were used to determine total sulfur concentrations in Alaska soil and plant material. Results were in close agreement with those obtained by turbidimetric and gravimetric methods and by similar combustion methods. 相似文献
19.
《Angewandte Chemie (Weinheim an der Bergstrasse, Germany)》2017,129(47):15314-15318
We demonstrate a novel crosslinked disulfide system as a cathode material for Li‐S cells that is designed with the two criteria of having only a single point of S−S scission and maximizing the ratio of S−S to the electrochemically inactive framework. The material therefore maximizes theoretical capacity while inhibiting the formation of polysulfide intermediates that lead to parasitic shuttle. The material we report contains a 1:1 ratio of S:C with a theoretical capacity of 609 mAh g−1. The cell gains capacity through 100 cycles and has 98 % capacity retention thereafter through 200 cycles, demonstrating stable, long‐term cycling. Raman spectroscopy confirms the proposed mechanism of disulfide bonds breaking to form a S−Li thiolate species upon discharge and reforming upon charge. Coulombic efficiencies near 100 % for every cycle, suggesting the suppression of polysulfide shuttle through the molecular design. 相似文献