- CHEMICAL STABILITY OF SODIUM BETA double prime -ALUMINA ELECTROLYTE IN SULFUR/SODIUM POLYSULFIDE MELTS.
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Immersion of sodium beta double prime -alumina electrolyte in sodium polysulfide and pure sulfur melts, at Na/S Battery operation temperatures, showed that the electrolyte was chemically attacked by the melts,and that the extent of degradation was affected by a number of factors, including surface morphology and chemistry of the electrolyte, melt composition, impurity contamination, etc. The corrsosion reactions mostly initiated and concentrated on defected areas, and were catalyzed by the presence of impurities such as water, moist air, oxygen, etc. The corrosion power of sodium polysulfide melts increased with the sulfur content in the range of Na//2S//2 to Na//2S//5.
- Liu,De Jonghe
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- Synthesis and Crystal Structure of Ternary SulfidesA3MS4withA=Na, Rb andM=Nb, Ta
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The new ternary sulfides Na3MS4and Rb3MS4(M=Nb, Ta) were prepared from tantalum nitride or niobium powder in the respective alkali metal polysulfide melt. Both sodium sulfides crystallize in form of yellow (Nb) or yellow-orange (Ta) needles in the orthorhombic space groupFdd2 withZ=32 anda=27.3034(4) A,b=28.4662(1) A, andc=7.9642(1) A,R/Rw=0.024/0.048 forM=Nb anda=27.2322(2) A,b=28.4264(2) A, andc=7.9634(6) A,R/Rw=0.066/0.177 forM=Ta. The rubidium sulfides were obtained as yellow (Nb) and orange (Ta) crystals with irregular shape. They crystallize in the orthorhombic space groupPnmawithZ=4 anda=9.6109(6) A,b=11.1013(7) A, andc=9.6390(6) A,R/Rw=0.030/0.072 forM=Nb anda=9.6084(5) A,b=11.1067(6) A, andc=9.6426(5) A,R/Rw=0.031/0.070 forM=Ta. The structures of all four compounds are built by stacking isolatedMS3-4units with the alkali metal ions.
- Niewa, Rainer,Vajenine, Grigori V.,Disalvo, Francis J.
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- Long-Life Room-Temperature Sodium–Sulfur Batteries by Virtue of Transition-Metal-Nanocluster–Sulfur Interactions
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Room-temperature sodium–sulfur (RT-Na/S) batteries hold significant promise for large-scale application because of low cost of both sodium and sulfur. However, the dissolution of polysulfides into the electrolyte limits practical application. Now, the design and testing of a new class of sulfur hosts as transition-metal (Fe, Cu, and Ni) nanoclusters (ca. 1.2 nm) wreathed on hollow carbon nanospheres (S@M-HC) for RT-Na/S batteries is reported. A chemical couple between the metal nanoclusters and sulfur is hypothesized to assist in immobilization of sulfur and to enhance conductivity and activity. S@Fe-HC exhibited an unprecedented reversible capacity of 394 mAh g?1 despite 1000 cycles at 100 mA g?1, together with a rate capability of 220 mAh g?1 at a high current density of 5 A g?1. DFT calculations underscore that these metal nanoclusters serve as electrocatalysts to rapidly reduce Na2S4 into short-chain sulfides and thereby obviate the shuttle effect.
- Zhang, Bin-Wei,Sheng, Tian,Wang, Yun-Xiao,Chou, Shulei,Davey, Kenneth,Dou, Shi-Xue,Qiao, Shi-Zhang
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- Catalytic behavior of hexaphenyldisiloxane in the synthesis of pyrite FeS2
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Functional small molecules afford opportunities to direct solid-state inorganic reactions at low temperatures. Here, we use catalytic amounts of organosilicon molecules to influence the metathesis reaction: FeCl2 + Na2S2 → 2NaCl + FeS2. Specifically, hexa
- Martinolich, Andrew J.,Neilson, James R.,Todd, Paul K.
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- Synthesis, structure, magnetic and optical properties of ternary thio-germanates: Ln4(GeS4)3 (Ln = Ce, Nd)
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Single crystals of two ternary thio-germanates containing rare-earth metals, Ln4(GeS4)3 (Ln = Ce (I), Nd (II)), have been isolated from the reaction of anhydrous rare-earth trichloride (LnCl 3) and ternary sodium thio-germanate (Na2GeS3) in evacuated quartz ampoules. We have determined the crystal structure of the compounds, which are isostructural to La4(GeS4) 3 and crystallize in trigonal system in the space group R3c with the cell dimensions: I, a = b = 19.375(3)A, c = 8.028(2) A, Z = 6; II, a = b = 19.250(3) A, c = 7.949(2) A, Z = 6. The structure is built with the complex network of two independent tricapped trigonal prisms of CeS9, in which Ge atoms occupy tetrahedral holes of sulfur atoms. The bulk synthesis of the two compounds has also been achieved by the stoichiometric combination of the elements. The magnetic and optical properties of the compounds have been investigated. The magnetic moments of 2.32 and 3.49 μB for I and II, respectively, are in good agreement with the theoretical magnetic moments of Ce and Nd in the +3 oxidation state. The optical band gap of I is found to be located around 2.3 eV, while the optical band gap of II lies around 2.62 eV. In addition, Raman spectroscopic characterizations have also been performed for I, II, and La4(GeS4)3.
- Choudhury, Amitava,Dorhout, Peter K.
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- Alkali-metal thiogermanates: Sodium channels and variations on the La3CuSiS7 structure type
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Five new isotypic quaternary chalcogenides containing rare-earth metal atoms crystallizing in the hexagonal noncentrosymmetric space group P63 (No. 173) with the La3CuSiS7 structure type have been synthesized by reacting the appropriate anhydrous rare-earth trichloride with sodium thiogermanate, Na2GeS3. The reaction between LnCl3 and Na2GeS3 in an evacuated fused-silica ampule produced high yields of good-quality crystals of NaLn3GeS7 [Ln = Ce (I), Nd (II), Sm (III), Gd (IV), and Yb (V)], while a similar reaction between EuCl3 and Na2GeS3 yielded a quinary chloride thiogermanate, Na1.2Eu3.4Cl2Ge3S9 (VI), incorporating a cyclic trimeric Ge3S9 building unit and adopting a structure related to La3CuSiS7. The crystal structure of the compounds comprises a complex network of bicapped trigonal-prismatic LnS8 and GeS4 tetrahedra, which creates channels along the [001] direction. The Na+ cations reside in these channels within trigonally distorted octahedral coordination environments, surrounded by six S atoms. For compounds III-V, the temperature dependence of the magnetic susceptibility indicates that these compounds are paramagnetic with μeff. = 1.86, 8.01, and 3.87 μB, for III-V, respectively. The experimental μeff for IV is close to the theoretical value of 7.94 for free Gd3+ ions, while μeff values for III and V deviate from their theoretical values of 0.86 and 4.54 μB for Sm3+ and Yb3+ ions, respectively. These compounds are semiconductors with optical band gaps of around 1.3 eV for III and V. Extended Hückel calculations suggest that the valence band comprises primarily S 3p and the bottom of the conduction band is dominated by empty rare-earth 5d orbitals. Compound VI exhibits a sharp optical absorption of around 2.18 eV, which is attributed to the f → d transition of EuII. The effective magnetic moment of 7.94 μB/Eu is in excellent agreement with the theoretical value of 7.94 μB for the free Eu2+ ion.
- Choudhury, Amitava,Dorhout, Peter K.
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- Ternary lanthanum sulfide selenides α-LaS2-xSex (022- (X=S, Se)
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Mixed lanthanum sulfide selenides LaS2-xSex (02-xSex compounds crystallize in space group P2 1/a, no. 14, and adopt the α-LnS2 (Ln=Y, LaLu) structure type with a pronounced site preference for the chalcogen atoms. The mixed chalcogenides form a complete miscible series with lattice parameters a=820849 pm, b=413425 pm and c=822857 pm (β≈90°) following Vegard's rule. Raman signals indicate the presence of mixed X22- dianions, a species rarely evidenced in literature, besides the well known anions S22- and Se22-. The band gaps of the LaS2-xSex compounds, determined by optical spectroscopy, decrease nearly linearly with increasing amount of selenium.
- Bartsch, Christian,Doert, Thomas
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- Multifunctional 5,6-dimethoxybenzo[d]isothiazol-3(2H)-one-N-alkylbenzylamine derivatives with acetylcholinesterase, monoamine oxidases and β-amyloid aggregation inhibitory activities as potential agents against Alzheimer's disease
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A series of 5,6-dimethoxybenzo[d]isothiazol-3(2H)-one-N-alkylbenzylamine derivatives were designed, synthesized and evaluated as potential multifunctional agents for the treatment of Alzheimer's disease (AD). The in vitro assays indicated that most of these derivatives were selective AChE inhibitors with good multifunctional properties. Among them, compounds 11b and 11d displayed comprehensive advantages, with good AChE (IC50 = 0.29 ± 0.01 μM and 0.46 ± 0.02 μM, respectively), MAO-A (IC50 = 8.2 ± 0.08 μM and 7.9 ± 0.07 μM, respectively) and MAO-B (IC50 = 20.1 ± 0.16 μM and 43.8 ± 2.0% at 10 μM, respectively) inhibitory activities, moderate self-induced Aβ1–42 aggregation inhibitory potency (35.4 ± 0.42% and 48.0 ± 1.53% at 25 μM, respectively) and potential antioxidant activity. In addition, the two representative compounds displayed high BBB permeability in vitro. Taken together, these multifunctional properties make 11b and 11d as a promising candidate for the development of efficient drugs against AD.
- Xu, Rui,Xiao, Ganyuan,Li, Yan,Liu, Hongyan,Song, Qing,Zhang, Xiaoyu,Yang, Ziyi,Zheng, Yunxiaozhu,Tan, Zhenghuai,Deng, Yong
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- Microwave-assisted synthesis, characterization, and thermal decomposition of rare-earth metal disulfides RES2 (RE = La, Pr, Nd)
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Microwave-assisted metathesis reactions from anhydrous rare-earth metal trichlorides and alkali metal polychalcogenides in dimethylformamide in the temperature interval 160 °C ≤ T ≤ 220 °C yield sub-micron and nanometer scaled particles of the rare-earth
- Bartsch, Christian,Ahrens, Eike,Doert, Thomas
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- Preparation of a carbon-14 analog of 2-[2-(4-(dibenzo[b, f][1,4]thiazepin-11-yl)piperazin-1-yl)ethoxy]ethanol
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2-[2-(4-(Dibenzo[b, f][1,4]thiazepin-11-yl)piperazin-1-yl)ethoxy]ethanol (Quetiapine) labeled with 14C in 11-position was synthesized in five steps from [carboxy-14C]anthranilic acid. The key precursor of the target product is [11-s
- Saadatjoo,Javaheri,Saemian,Amini
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- Poly(butylene disulfide) and poly(butylene tetrasulfide): Synthesis, cure and investigation of polymerization yield and effect of sulfur content on mechanical and thermophysical properties
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In this work, two polysulfide polymers were synthesized by use of 1,4-dichlorobutane and aqueous sodium disulfide or sodium tetrasulfide. The polymers were cured at 85 °C. The structural characteristics of non-cured and cured samples were identified by Raman and FT-IR spectroscopy. The morphological and the thermophysical properties of all samples were investigated by X-ray diffraction (XRD) and differential scanning calorimetry (DSC). Also, the mechanical properties and hardness of all samples were investigated by tensile test and Shore A. Moreover, the effects of temperature and ethanol on polymerization were investigated. Aqueous monomers were characterized by UV-VIS-NIR spectroscopy. The molecular weight of the synthesized samples was determined by 1H NMR spectroscopy. The results showed that, before curing, poly(butylene tetrasulfide) (PBTS) due to amorphous structure does not have a melting peak and both polymers have a very low glass transition temperature. Without ethanol, no polymerization reaction takes place. Before curing, poly(butylene disulfide) (PBDS) is brittle and PBTS has an elastomeric behavior, but after curing PBDS also behaves as elastomer. The curing times of the two polymers are close to each other, but their mechanical properties and hardness are different.
- Sheydaei, Milad,Edraki, Milad,Javanbakht, Shiva,Alinia-Ahandani, Ebrahim,Soleimani, Mahdieh,Zerafatkhah, Alireza
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p. 578 - 584
(2021/01/21)
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- Preparation method of tert-butyl disulfide
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The invention discloses a preparation method of tert-butyl disulfide, and the method comprises the following steps: reacting di-tert-butyl sulfite with a disodium disulfide solution, and purifying toobtain the product. According to the method, the di-tert-butyl sulfite is used as a raw material; according to an existing route, tert-butyl mercaptan or tert-butyl chloride is generally adopted as araw material; compared with the existing route, the method has innovative advantages, the raw materials for preparing the di-tert-butyl sulfite are low in price and easy to purchase; moreover, the smell is small and easy to control, the whole reaction condition is mild, the post-treating operation is simple, the production can be carried out only by using conventional equipment, and the problems of large production smell, difficult treating of the environment, high production cost and unsuitability for industrial production in the existing method are solved.
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(2020/08/02)
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- Preparation method of diethyl disulfide
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The invention relates to a preparation method of diethyl disulfide, comprising the following steps: using sodium sulfide, sulfur and diethyl sulfate as raw materials, carrying out stirring reaction at60-70 DEG C for 3-5 hours under the action of a phase transfer catalyst, and carrying out after-treatment on the reaction solution after the reaction is finished. According to the method, diethyl sulfate is used as an ethylation reagent, the cost is low, the reaction is easy to operate, the production period is short, and the ethyl utilization rate is high.
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Paragraph 0010; 0013-0015
(2020/06/02)
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- Discovery of Ziresovir as a Potent, Selective, and Orally Bioavailable Respiratory Syncytial Virus Fusion Protein Inhibitor
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Ziresovir (RO-0529, AK0529) is reported here for the first time as a promising respiratory syncytial virus (RSV) fusion (F) protein inhibitor that currently is in phase 2 clinical trials. This article describes the process of RO-0529 as a potent, selective, and orally bioavailable RSV F protein inhibitor and highlights the in vitro and in vivo anti-RSV activities and pharmacokinetics in animal species. RO-0529 demonstrates single-digit nM EC50 potency against laboratory strains, as well as clinical isolates of RSV in cellular assays, and more than one log viral load reduction in BALB/c mouse model of RSV viral infection. RO-0529 was proven to be a specific RSV F protein inhibitor by identification of drug resistant mutations of D486N, D489V, and D489Y in RSV F protein and the inhibition of RSV F protein-induced cell-cell fusion in cellular assays.
- Zheng, Xiufang,Gao, Lu,Wang, Lisha,Liang, Chungen,Wang, Baoxia,Liu, Yongfu,Feng, Song,Zhang, Bo,Zhou, Mingwei,Yu, Xin,Xiang, Kunlun,Chen, Li,Guo, Tao,Shen, Hong C.,Zou, Gang,Wu, Jim Zhen,Yun, Hongying
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supporting information
p. 6315 - 6329
(2019/07/09)
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- Selective and Facile Synthesis of Sodium Sulfide and Sodium Disulfide Polymorphs
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Na2S and Na2S2 were selectively synthesized using a microwave-assisted thermal treatment of a Na+/S solution in tetraglyme between 100 and 200 °C, considerably lower than that of current routes. This novel synthetic pathway yields the Na2S phase in high purity and allows for good selectivity between the polymorphs of Na2S2 (α and β phases). These materials show promising electrochemical properties and are particularly interesting for the continued development of Na-S batteries.
- El-Shinawi, Hany,Cussen, Edmund J.,Corr, Serena A.
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supporting information
p. 7499 - 7502
(2018/07/10)
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- 4-process for the preparation of cyclic lactam base aniline
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The invention relates to the field of medicines, specifically relates to a preparation method of an aniline compound and particularly relates to a preparation method of 4-cyclic lactam group aniline. A synthesis method of the 4-cyclic lactam group aniline
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Paragraph 0027
(2017/04/05)
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- Examination of mercaptobenzyl sulfonates as catalysts for native chemical ligation: Application to the assembly of a glycosylated Glucagon-Like Peptide 1 (GLP-1) analogue
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3/4-Mercaptobenzyl sulfonates were investigated as aryl thiol catalysts for native chemical ligation (NCL). Whilst catalysing NCL processes at a similar rate to 4-mercaptophenyl acetic acid (MPAA), the increased polarity and solubility of 3-mercaptobenzyl
- Cowper, Ben,Sze, Tsz Mei,Premdjee, Bhavesh,Bongat White, Aileen F.,Hacking, Andrew,Macmillan, Derek
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supporting information
p. 3208 - 3210
(2015/06/30)
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- Pyrite formation via kinetic intermediates through low-temperature solid-state metathesis
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The preparation of materials with limited phase stabilities yet high kinetic activation barriers is challenging. Knowledge of their possible formation pathways aids in addressing these challenges. Metathesis reactions present an approach to circumvent these barriers; however, solid-state metathesis reactions are often too rapid from extensive self-heating to understand the reaction. The stoichiometric reaction of MCl2 salts (M = Mn, Fe, Co, Ni, Cu, Zn) with Na2S2 enables the formation of pyrite (FeS2), CoS2, and NiS2 at low temperatures (250-350 °C). Na2S2 has the same polyanionic dimer as found in the pyrite structure, which would suggest the possibility of a facile ion-exchange reaction. However, from high-resolution synchrotron X-ray diffraction and differential scanning calorimetry, the energetic driving force does not appear to result solely from NaCl formation but also from formation of intermediate and pyrite phases. It is apparent that the reaction proceeds through polyanionic disproportionation and formation of a low-density alkali-rich intermediate, followed by anionic comproportionation and atomic rearrangement into the pyrite phase. These results have profound implications for the use of low-temperature metathesis in achieving materials by design.
- Martinolich, Andrew J.,Neilson, James R.
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p. 15654 - 15659
(2015/02/19)
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- Synthesis of a phenolic precursor and its efficient O-[18F] fluoroethylation with purified no-carrier-added [18F]2-fluoroethyl brosylate as the labeling agent
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[18F]2-Fluoroethyl-p-toluenesulfonate also called [ 18F]2-fluoroethyl tosylate has been widely used for labeling radioligands for positron emission tomography (PET). [18F]2- Fluoroethyl-4-bromobenzenesulfonate, also called [18F]2-fluoroethyl brosylate ([18F]F(CH2)2OBs), was used as an alternative radiolabeling agent to prepare [18F]FEOHOMADAM, a fluoroethoxy derivative of HOMADAM, by O-fluoroethylating the phenolic precursor. Purified by reverse-phase HPLC, the no-carrier-added [ 18F]F(CH2)2OBs was obtained in an average radiochemical yield (RCY) of 35%. The reaction of the purified and dried [ 18F]F(CH2)2OBs with the phenolic precursor was performed by heating in DMF and successfully produced [18F] FEOHOMADAM, after HPLC purification, in RCY of 21%. Copyright
- Jarkas, Nashwa,Voll, Ronald J.,Goodman, Mark M.
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p. 539 - 543
(2013/11/06)
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- Synthesis and characterization of new 2-pyrimidyl chalcogen (S, Se, Te) compounds: X-ray crystal structure of bis(4,6-dimethyl-2-pyrimidyl)diselenide and 4,6-dimethyl-2-(phenylselanyl)pyrimidine
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New and synthetically important symmetrical bis(4,6-dimethyl-2-pyrimidyl) dichalcogenides have been synthesized by reacting 4,6-dimethyl-2- chloropyrimidine with the corresponding dichalcogenide (E2 2- where E = S, Se, Te) ion. The u
- Bhasin,Arora, Ekta,Grover, Alka S.,Jyoti,Singh,Mehta,Bhasin, Aman K.K.,Jacob
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p. 137 - 141
(2013/06/26)
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- Structural frustration and occupational disorder: The rare earth metal polysulfides Tb8S14.8, Dy8S14.9, Ho8S14.9, and Y8S14.8
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Dark red crystals of Y8S14.8, Tb8S 14.8, Dy8S14.9, and Ho8S 14.9 have been obtained following different reaction routes. The isostructural title compounds adopt the Gd8Se15 type, a 24-fold superstructure of the ZrSSi-type and can be described in space group A112 (non standard setting of C121, no. 5) with lattice parameter of a = 11.505(1) A, b = 15.385(1) A, c = 15.726(1) A, and γ = 90.21(2)° for Y8S15-x; a = 11.660(1) A, b = 15.468(2) A, c = 15.844(2) A, and γ = 90.19(2)° for Tb8S15-x; a = 11.584(1) A, b = 15.340(2) A, c = 15.789(2) A, and γ = 90.34(2)° for Dy8S 15-x; and a = 11.538(1) A, b = 15.288(2) A, c = 15.740(2) A, and γ = 90.23(1)° for Ho8S15-x, respectively. The structure consists of an alternating stacking of puckered [RES] (RE, rare-earth metals) double slabs and planar sulfur layers along [001]. The planar sulfur layers have a complex arrangement of S2 2- dinuclear dianions, isolated S2- ions, and vacancies. All compounds contain trivalent rare-earth metal ions, for Tb8S 15-x and Dy8S15-x antiferromagnetic order was found at TN = 5.4(2) K and 3.8(1) K, respectively. Short wavelength cutoff optical band gaps of 1.6 to 1.7 eV were determined.
- Doert, Thomas,Graf, Christian,Vasilyeva, Inga G.,Schnelle, Walter
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p. 282 - 289
(2012/03/07)
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- Rare earth metal disulfides - Syntheses and crystal structures of α-CeS2, α-NdS2, β-LaS2, β-CeS2, and β-PrS2
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α-CeS2 and α-NdS2 were obtained by a metathesis reaction of the anhydrous trichlorides LfiCI3 (Ln = Ce, Nd) and Na2S2 at 1070 K. The two compounds adopt a monoclinic structure type, the so-called CeSe
- Schleid, Thomas,Lauxmann, Petra,Graf, Christian,Bartsch, Christian,Doert, Thomas
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p. 189 - 196
(2009/05/27)
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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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p. 147 - 154
(2009/05/06)
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- A NOVEL METHOD OF PREPARATION OF IMATINIB
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Imatinib base (I) is prepared by a novel method by reduction of N-(2-Methyl-5-nitrophenyl)-4-(3-pyridyl)-2-pyrimidine amine (IV) employing sodium disulphide and condensing the resulting amine N-(5-Amino-2-methylphenyl)-4-(3-pyridyl)-2-pyrimidinamine (II) with the acid chloride 4-[(4-Methylpiperazin-1-yl) methyl]benzoylchloride dihydrochloride (III), in presence of potassium carbonate.
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(2008/12/04)
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- Preparation of sulfide chain-bearing organisilicon compounds
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A sulfide chain-bearing organosilicon compound having the average compositional formula: [in-line-formulae](R1O)(3-p)(R2)pSi—R3—S(R4—Sm)q—R4—S—R3—Si(OR1)(3-p)(R2)p [/in-line-formulae]is prepared at low costs and in high yields by reacting a halogen-terminated organosilicon compound having the formula: (R1O)(3-p)(R2)pSi—R3—S—R4—X, and optionally a halide having the formula: X—R4—X and/or sulfur with an aqueous solution or dispersion of a polysulfide M2Sn or hydrate thereof in the presence of a phase transfer catalyst. R1 and R2 are monovalent C1-4 hydrocarbon groups, R3 and R4 are divalent C1-10 hydrocarbon groups, m has an average value of 2-6, n has an average value of 2-6, p is 0, 1 or 2, q is 1, 2 or 3, X is halogen, and M is ammonium or alkali metal.
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(2008/06/13)
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- Pentafluorosulfanylphenyl-substituted benzoylguanidines, processes for their preparation, their use as medicament or diagnostic aid, and medicament comprising them
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Pentafluorosulfanylphenyl-substituted benzoylguanidines of the formulae I and II in which R1, R1′, R2, R2′, R3, R3′, R4 and X have the meanings indicated in the claims, are suitable as antiarrhythmic medicaments with a cardioprotective component for the prophylaxis of infarction and treatment of infarction and for the treatment of angina pectoris. They also inhibit preventively the pathophysiological processes associated with the development of ischemia-induced damage, especially in the triggering of ischemia-induced cardiac arrhythmias.
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(2010/02/10)
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- Structural variety and multiple isomerism in 1-(dimethylamino)propyl-2- chalcogenolate and 2-(dimethylamino)propyl-1-chalcogenolate complexes of palladium(II) and platinum(II): Synthesis, spectroscopy and structures
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Isomeric dichalcogenides [Me2NCH(Me)CH2E]2 [(N∩E**)2] and [Me2NCH 2CH(Me)E]2 [(N∩E*)2] (E = S, Se, Te) have been obtained by the reactions of NaSH or M′2E2 (M′ = Na or K) with Me2NCH2CHMeCl. The former reaction affords mainly (N∩E**)2 (E = S) while from the latter mixtures of (N∩E**)2 and (N∩E**)2 [referred to as (N∩E)2, E = S, Se, Te] were isolated, the ratios in the mixtures depending on the chalcogen. Reactions of (N∩E)Na with [M2Cl2(μ-Cl) 2(PR3)2] gave complexes (MCl(N∩E)(PR 3)] (M = Pd or Pt). These chiral, mixed-ligand complexes have been characterised by elemental analysis, IR, UV/Vis and NMR (1H, 13C, 31P, 77Se, 125Te, 195Pt) spectroscopy, and, in part, by X-ray structure analysis. The complexes display a typical pattern of mutually trans-oriented neutral (P and N) and anionic (Cl and E) donor atoms in an approximately square-planar environment. In contrast to the platinum(II) analogues, the X-ray structures of the complexes [PdCl(N∩E) (PMePh2)] (E = S or Se) revealed both a conformational isomerism of the five-membered chelate ring and, for Se, the co-crystallisation of complexes with both the N∩E* and N∩E** isomeric ligands. The thermal behaviour of some complexes has been investigated. Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2004.
- Dey, Sandip,Kumbhare, Liladhar B.,Jain, Vimal K.,Schurr, Thilo,Kaim, Wolfgang,Klein, Axel,Belaj, Ferdinand
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p. 4510 - 4520
(2007/10/03)
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- Aromatic hydrocarbon-catalyzed direct reaction of sulfur and sodium in a heterogeneous system: Selective and facile synthesis of sodium monosulfide and disulfide
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Sodium disulfide and monosulfide were selectively formed via the direct reaction of sulfur and an equimolar amount of sodium in 1,2-dimethoxyethane at 70 °C in the presence of a catalytic amount of aromatic hydrocarbons and ketone.
- Takata, Toshikazu,Saeki, Daisaku,Makita, Yoshimasa,Yamada, Nobuo,Kihara, Nobuhiro
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p. 3712 - 3714
(2008/10/08)
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- Direct preparation of anhydrous sodium oligosulfides from metal sodium and elemental sulfur in aprotic organic media directed toward synthesis of silane coupling agent
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Anhydrous sodium oligosulfide was prepared by the heterogeneous reaction of metal sodium and elemental sulfur in aprotic solvents. The oligosulfide consisted of a mixture of several Na2Sn (n = 2 - 8). Organic oligosulfides (R2Sn, n ≥ 2) including moisture-sensitive one were synthesized by the reaction with organic halides in high yeilds under mild conditions.
- Yamada, Nobuo,Furukawa, Mutsuhisa,Nishi, Masayuki,Takata, Toshikazu
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p. 454 - 455
(2007/10/03)
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- Synthesis of antisense oligonucleotides: Replacement of 3H-1,2-benzodithiol-3-one 1,1-dioxide (Beaucage reagent) with phenylacetyl disulfide (PADS) as efficient sulfurization reagent: From bench to bulk manufacture of active pharmaceutical ingredient
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It is demonstrated that phosphorothioate oligodeoxyribonucleotides can be synthesized on scales from 1 μmol to 150 mmol using phenylacetyl disulfide (PADS) as an efficient and economical replacement for Beaucage reagent. A 0.2 M solution of PADS in a mixt
- Cheruvallath, Zacharia S.,Carty, Recaldo L.,Moore, Max N.,Capaldi, Daniel C.,Krotz, Achim H.,Wheeler, Patrick D.,Turney, Brett J.,Craig, Stephen R.,Gaus, Hans J.,Scozzari, Anthony N.,Cole, Douglas L.,Ravikumar, Vasulinga T.
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p. 199 - 204
(2013/09/07)
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- Raman Spectroscopy Study of the Reaction between Sodium Sulfide or Disulfide and Sulfur: Identity of the Species Formed in Solid and Liquid Phases
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The reactions of sodium sulfide or disulfide with sulfur, when heated, are examined through Raman spectroscopy. It is shown that whatever the composition of the mixtures, the solid sodium sulfide or disulfide transforms into the crystalline α-Na2S4 phase in a first step, with α- or β-Na2S2 as an intermediate. The reaction, which proceeds when the sulfur melts, is assumed to be related to the polymerization-depolymerization mechanism responsible for the formation of smaller rings andsulfur chains in molten S8. This confirms the strong reactivity of the radical sulfur chain molecules. This solid α-Na2S4 formed may furt her react around 200°C with Na2S in excess. This solid-state reaction leads to the formation of β-Na2S2. It is shown that, after theliquid of composition Na2S4 is heated above 400°C, a glass is fo rmed upon cooling. Annealing this glass around 124°C yields a newγ-Na2S4 crystalline phase where the S4(2-) anions have a smaller torsion angle. This new phase is metastable and transforms into the .alp ha. phase upon prolonged heating at 200°C. The solids, formed from heating the mixtures Na2S + (n/8)S8 or Na2S2 + (n'/8)S8 with n' = n-1,for n 3 are only crystalline β-Na2S2 or α,γ-N a2S4 and glassy Na2S4, and for 3 4, higher polysulfides decompose under crystallization into Na2S5 and sulfur. The liquids formed from these mixtures show the formation of all the S(n+1)(2-) anions although Na2S3 and Na2S6 do not crystallize from these liquids.
- Jaroudi, Omar El,Picquenard, Eric,Gobeltz, Noelle,Demortier, Antoine,Corset, Jaques
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p. 2917 - 2923
(2008/10/08)
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- Low-temperature precursor synthesis of crystalline nickel disulfide
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Pure, crystalline nickel disulfide is synthesized within seconds from the solid-state reaction between potassium hexafluoronickelate(IV) and sodium pentasulflde hydrate at ~65°C. The nickel disulfide product is isolated by simply washing away the byproduct salts. The reaction is influenced by the hydration and the sulfur content of the sulfiding agent and by the transition-metal precursor. Increasing the hydration of the sodium pentasulfide or lowering the oxidation state of the nickel in potassium hexafluoronickelate from Ni(IV) to Ni(III) favors a less crystalline product. Reactions containing sulfiding agents with lower sulfur content, such as sodium monosulfide or sodium disulfide, produce mixtures of nickel monosulfide and nickel disulfide. X-ray diffraction, thermogravimetric analysis, and differential scanning calorimetry results are presented.
- Bonneau, Philippe R.,Shibao, Robert K.,Kaner, Richard B.
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p. 2511 - 2514
(2008/10/08)
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- On the Autoxidation of Aqueous Sodium Polysulfide
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Aqueous sodium polysulfide of composition in the range Na2S2.0 to Na2S4.6 undergoes autoxidation by eiher air or pure oxygen at temperatures of between 23 and 40 deg C according to the equation Na2S2+x + 3/2 O2 -> Na2S2O3 + x/8 S8.Iodometric determination, vibrational spectra and ion-pair chromatography showed that neither sulfate, sulfite nor polythionates are formed and that the sulfur precipitated consists of S8 (> 99percent). - Key words: Sodium Polysulfide, Autoxidation, Sodium Thiosulfate, Elemental Sulfur, HPLC
- Steudel, Ralf,Holdt, Gabriele,Nagorka, Regine
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p. 1519 - 1522
(2007/10/02)
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