- Trimethylsulfonium Lead Triiodide: An Air-Stable Hybrid Halide Perovskite
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We report on the synthesis, characterization, and optoelectronic properties of the novel trimethylsulfonium lead triiodide perovskite, (CH3)3SPbI3. At room temperature, the air-stable compound adopts a hexagonal crystal structure with a 1D network of face-sharing [PbI6] octahedra along the c axis. UV-vis reflectance spectroscopy on a pressed pellet revealed a band gap of 3.1 eV, in agreement with first-principles calculations, which show a small separation between direct and indirect band gaps. Electrical resistivity measurements on single crystals indicated that the compound behaves as a semiconductor. According to multi-temperature single-crystal X-ray diffraction, synchrotron powder X-ray diffraction, Raman spectroscopy, and differential scanning calorimetry, two fully reversible structural phase transitions occur at ?5 and ca. ?100 °C with reduction of the unit cell symmetry to monoclinic as temperature decreases. The role of the trimethylsulfonium cation regarding the chemical stability and optoelectronic properties of the new compound is discussed in comparison with APbI3 (A = Cs, methylammonium, and formamidinium cation), which are most commonly used in perovskite solar cells.
- Kaltzoglou, Andreas,Stoumpos, Constantinos C.,Kontos, Athanassios G.,Manolis, Georgios K.,Papadopoulos, Kyriakos,Papadokostaki, Kyriaki G.,Psycharis, Vasilis,Tang, Chiu C.,Jung, Young-Kwang,Walsh, Aron,Kanatzidis, Mercouri G.,Falaras, Polycarpos
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- A Novel Synthesis of Methyltin Tri-iodide with Environmental Implications
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Methyltin tri-iodide and methylsulphur species are produced by an unusual heterogeneous reaction between MeI and SnS in water at room temperature which may bear on ubiquitous occurrence of methylstannanes in the environment.
- Manders, William F.,Olson, Gregory J.,Brinckman, Frederick E.,Bellama, Jon M.
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- Synthesis and Biological Evaluation of Bromo- and Fluorodanicalipin A
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We disclose the syntheses of (+)-bromodanicalipin A as well as (±)-fluorodanicalipin A. The relative configuration and ground-state conformation in solution of both molecules was secured by J-based configuration analysis which revealed that these are identical to natural danicalipin A. Furthermore, preliminary toxicological investigations suggest that the adverse effect of danicalipin A may be due to the lipophilicity of the halogens. Halologs: The syntheses of bromo- and fluorodanicalipin A are reported and the ground-state conformation was determined by J-based configuration analysis (see scheme, R=H). A preliminary comparative study of their toxicology suggests that the adverse effect arises from the lipophilicity of the halogens which counterbalance the polar C14 sulfate.
- Fischer, Stefan,Huwyler, Nikolas,Wolfrum, Susanne,Carreira, Erick M.
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- Reactions of (triethylstannylthioalkyl)trialkoxysilanes and (triethylstannylthioalkyl)trialkoxysilatranes with methyl iodide
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Reactions of (triethylstannylthioalkyl)trimethoxysilanes Et 3SnS(CH2)nSi(OMe)3 (n = 1, 2) and (triethylstannylthioalkyl)trialkoxysilatranes Et3Sn(CH2) n Sa [hereinafter Sa = Si(O
- Sorokin,Voronkov
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- Synthesis, characterization and optoelectronic properties of chemically stable (CH3)3SPbI3?xBrx and (CH3)3SPbI3?xClx (x?=?0, 1, 2, 3) perovskites
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We report on the novel series of (CH3)3SPbI3?xBrx and (CH3)3SPbI3?xClx (x = 0, 1, 2, 3) perovskite compounds. X-ray diffraction analysis shows that the solid solutions of (CH3)3SPbI3?xBrx (x = 0, 1, 2, 3) and (CH3)3SPbI3?xClx (x = 0, 1, 2) crystallize in hexagonal symmetry (space group P63mc, No. 186) with 1D columns of face-sharing [PbX6] octahedra. (CH3)3SPbCl3 crystallizes in orthorhombic symmetry (space group Pnma, No. 62) forming 3D network of vertex- and face-sharing [PbCl6] octahedra. Optical and vibrational properties were investigated using UV–vis reflectance, photoluminescence and Raman spectroscopy at room temperature. The compounds show high chemical stability in ambient air at temperatures up to 80 °C and under solar simulator, in contrast to the hygroscopic CH3NH3PbI3 or CH(NH2)2PbI3 that are commonly used in perovskite solar cells. First principles theoretical ab initio and efficient semiempirical extended Hückel calculations were performed to evaluate the energy band gap values, whose results are in good agreement with the experimentally determined values.
- Kaltzoglou, Andreas,Elsenety, Mohamed M.,Koutselas, Ioannis,Kontos, Athanassios G.,Papadopoulos, Kyriakos,Psycharis, Vassilis,Raptopoulou, Catherine P.,Perganti, Dorothea,Stergiopoulos, Thomas,Falaras, Polycarpos
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- Mechanochemical Synthesis of 1,2-Diketoindolizine Derivatives from Indolizines and Epoxides Using Piezoelectric Materials
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A simple and efficient mechanochemical-induced approach for the synthesis of 1,2-diketoindolizine derivatives has been developed. BaTiO3 was used as the piezoelectric material in this transformation. This method features no usage of solvent, simple experimental operation, scalable potential, and high conversion efficiency, which make it attractive and practical.
- Wang, Yumei,Zhang, Ziwu,Deng, Lichan,Lao, Tianfeng,Su, Zhengquan,Yu, Yue,Cao, Hua
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supporting information
p. 7171 - 7176
(2021/09/14)
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- Method for preparing naproxen intermediate
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A technical scheme of the invention provides a method for preparing a naproxen intermediate represented by a chemical structural formula I. Preparation reactions are as follows: 6-methoxy-2-acetonaphthone and trimethyl sulfonium hydrogen sulfate are subjected to an epoxidation reaction in the presence of alkali so as to prepare 2-(6-methoxynaphthyl)-1,2-epoxypropane, the 2-(6-methoxynaphthyl)-1,2-epoxypropane is subjected to catalyzed rearrangement through silica gel or FeCl3 and then reacts with hydroxylamine hydrochloride, thereby preparing an intermediate, i.e., 2-(6-methoxy-2-naphthyl)propyl oxime (I) in one step. Naproxen is prepared by employing a one-pot method through a key intermediate, i.e., 2-(6-methoxy-2-naphthyl)propyl oxime.
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Paragraph 0095-0100
(2020/12/08)
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- Stereoselective Cyclopropanation of (-)-Levoglucosenone Derivatives Using Sulfonium and Sulfoxonium Ylides
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The synthesis of tri- and tetrasubstituted cyclopropanes from 3-aryl-substituted levoglucosenones (LGO) has been developed. In contrast to the unstabilised ylide dimethylsulfonium methylide which gives epoxides from LGO via 1,2-addition, we have found that the soft nucleophile dimethylsulfoxonium methylide affords cyclopropanes in moderate yields from LGO and in excellent yields and stereoselectivity with 3-aryl LGO derivatives. The use of 1,1,3,3-tetramethylguanidine as base in DMSO to generate the ylide provided the best yields and shortest reaction times. Ester stabilised sulfonium ylides could also be used to generate tetrasubstituted cyclopropane derivatives. One of the products was converted into a cyclopropyl lactone via Baeyer-Villiger oxidation to demonstrate the utility of applying cyclopropanation chemistry to LGO. Georg Thieme Verlag Stuttgart.New York.
- Ledingham, Edward T.,Merritt, Christopher J.,Sumby, Christopher J.,Taylor, Michelle K.,Greatrex, Ben W.
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supporting information
p. 2652 - 2662
(2017/06/13)
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- Preparation method of medetomidine and intermediate thereof
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The invention relates to a preparation method of 2-(2, 3-xylyl)-2-methyloxirane. The method is characterized in that the preparation process includes the following reaction shown as the specification, wherein Y is selected from Cl, Br, I, CH3SO4 or HSO4; alkali is selected from KOH, NaOH, LiOH, CsOH, K2CO3, Li2CO3, Cs2CO3, Na2CO3, EtONa, EtOK, (CH3)2CHONa, (CH3)2CHOK, (CH3)3CONa, (CH3)3COK, NH2Na or NH2K. The invention adopts the synthesis method using the 2-(2, 3-xylyl)-2-methyloxirane critical intermediate to prepare medetomidine.
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Paragraph 0076; 0077; 0078; 0079
(2017/08/28)
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- ARYL-ALKYLAMINES AND HETEROARYL-ALKYLAMINES AS PROTEIN KINASE INHIBITORS
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The invention provides a compound of the formula (II): or a salt, solvate, tautomer or N-oxide thereof; wherein n is 0 or 1; one of Y1 and Y2 is CH and the other is selected from CH, CR8 and N; q is 0, 1 or 2 provided that q is 0 or 1 when Y1 or Y2 is CR8; R1 is an aryl or heteroaryl group of 5 to 10 ring members; R2a and R3a each are hydrogen, C1-4 hydrocarbyl or C1-4 acyl wherein the hydrocarbyl and acyl moieties are optionally substituted by fluorine, hydroxy, amino, methylamino, dimethylamino or methoxy; or NR2aR3a forms an imidazole group or a saturated monocyclic 4-7 membered heterocyclic group optionally containing a second heteroatom ring member selected from O and N; R18 is hydrogen or methyl; R19 is hydrogen or methyl; R24 is hydrogen or R24, R2a and the intervening nitrogen atom and carbon atoms together form an azetidine, pyrrolidine or piperidine ring; R25 is hydrogen or a C1-4 alkyl group wherein the C1-4 alkyl group is optionally substituted by hydroxy or amino provided that there are at least two carbon atoms between the hydroxy or amino group and the oxygen atom to which R25 is attached; and R4 and R5 each are hydrogen or a substituent as defined in the claims
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Page/Page column 209-210
(2010/11/25)
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- Trialkylsulfonium dicyanamides - A new family of ionic liquids with very low viscosities
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Trialkylsulfonium dicyanamides show surprisingly low viscosities down to -20 °C and are therefore highly interesting liquid materials for separation processes and electrolyte applications at low temperatures. The Royal Society of Chemistry 2005.
- Gerhard, Dirk,Alpaslan, Samim Cenk,Gores, Heiner Jakob,Uerdingen, Marc,Wasserscheid, Peter
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p. 5080 - 5082
(2007/10/03)
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- Molten and Solid Trialkylsulfonium Iodides and Their Polyiodides as Electrolytes in Dye-Sensitized Nanocrystalline Solar Cells
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The overall solar-to-electric energy conversion efficiencies in solar simulators, and the incident monochromatic photon-to-current-efficiencies (IPCE) was measured for a selection of molten salt electrolytes to reveal their possible use as electrolytes in dye-sensitized nanocrystalline solar cells (DNSC). The IPCE results of (Et2MeS)I and (Bu2MeS)I were stable above 55% from 400 to 550 nm and then decreased on the red side of the spectra. The addition of iodine to (Bu2MeS)I and (Bu2EtS)I indicated increasing IPCE values at 520-540 nm; from 55 to 60% and 38 to 46%, respectively. (Te2MeS)I, (Bu2MeS)I, and (Bu2EtS)I showed good conducting abilities at ambient conditions and provided good light-to-electricity conversion efficiencies while used as electrolytes in DNSC. The liquid electrolytes (Et2MeS)I provided the highest conversion efficiencies at room temperature.
- Paulsson, Helene,Hagfeldt, Anders,Kloo, Lars
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p. 13665 - 13670
(2007/10/03)
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- Synthesis and novel reactivity of halomethyldimethylsulfonium salts
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Iodomethyl-, chloromethyl-, and fluoromethyldimethylsulfonium salts, 4b-d, have been synthesized and are observed to be highly reactive molecules that exhibit extraordinary diversity with respect to the nature of their reactivity, undergoing facile direct substitution (SN2) reactions, but also being highly susceptible to electron-transfer reactions. Cyclic voltametry experiments indicated that the iodomethyldimethylsulfonium compound, 4b, is a potent electron acceptor, even surpassing the reactivity of perfluoro-n-alkyl iodides in that capacity. The iodo- and chloromethyldimethylsulfonium salts, 4b,c, as well as the analogous iodomethyltrimethylammonium salt, 3a, are shown to be reactive SET acceptors.
- Xu, Yuelian,Fletcher, Michelle,Dolbier Jr., William R.
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p. 3460 - 3465
(2007/10/03)
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- Reactions of Charged Substrates. 8. The Nucleophilic Substitution Reactions of (4-Methoxybenzyl)dimethylsulfonium Chloride
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Displacement reactions on the title compound (1) occur only for nucleophiles with intermediate hardness. Nucleophiles that react display a range of mechanisms. 1 reacts with the neutral nucleophile pyridine-d5 through a mixed SN1/SN2 mechanism; salt added to control ionic strength affects the rate for the unimolecular process, but has no effect on the bimolecular rate constant. The mechanism of displacement by N3- and SO32- depends on the presence or absence of exogenous salt. At constant ionic strength, the mechanism is mixed SN1/SN2 over most of the range of [Nu]. With nucleophile only present, plots of kobsd vs [Nu] exhibit severe breaks that are not the result of salt effects. Analysis of rate constants and product ratios suggests that at low [Nu] reaction occurs simultaneously through concerted Hughes-Ingold SN2 and preassociation-concerted mechanisms. At high [Nu], displacement occurs only through the preassociation-concerted mechanism. Comparison of these results with data for gas-phase dissociation of benzyl dimethylsulfoniums and with solution results for benzyl pyridiniums suggests that the intrinsic stability of the intermediate does not necessarily determine the mechanism.
- Buckley, Neu,Oppenheimer, Norman J.
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p. 540 - 551
(2007/10/03)
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- Facile One Pot Thermal Dehydration and Dethioacetalization of β-Hydroxydithioacetals with Dimethyl sulphoxide: Synthesis of α,β-Unsaturated Aldehydes
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The acyclic and cyclic β-hydroxydithioacetals 3a-m and 4a-b obtained by sodium borohydride reduction (or Grignard addition) of the corresponding β-oxodithioacetals 2a-m are shown to undergo facile one pot thermal dehydration and dethioacetalization in the presence of dimethyl sulphoxide to afford the corresponding ene- and polyene aldehydes 5a-m and 6a-b in good yields.The probable mechanism of dethioacetalization with dimethyl sulphoxide has also been discussed.
- Rao, Ch. Srinivasa,Chandrasekharam, M.,Patro, Balaram,Ila, Hiriyakkanavar,Junjappa, Hiriyakkanavar
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p. 5783 - 5794
(2007/10/02)
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- Polylithium Complexes from Phenyl-substituted 1,6,6aλ4-Trithiapentalenes and Related Compounds and Lithium
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Phenyl-substituted 1,6,6aλ4-trithiapentalenes (1a-d) and 3H-1,2-dithiole-3-thiones (2a,b), 2-(4-phenyl-3H-1,2-dithiol-3-ylidene)acetophenone (3), and 1,5-diphenyl-1,3,5-pentanetrione (4) react in tetrahydrofuran or 2-methyltetrahydrofuran at 0 deg C with 7-10 Li/mol to form highly reactive, soluble polylithium complexes.These can be precipitated from solution by addition of pentane and have the composition A Li7-10*THF, where A = starting compound.The polylithium complex obtained from 1a and 10 Li is suggested to have the constitution 5a on the basis of reaction with water, methyl iodide, pentacene, and hydrogen, respectively.The assumption that 5a and the analogous complex 5b (formed by reacting 1b and 9 Li) contain Li2S molecules in complexed form is supported in particular by solid state 7Li and 1H NMR measurements.
- Bogdanovic, Borislav,Cordi, Alexis,Stepowska, Halszka,Locatelli, Paolo,Wermeckes, Bernd,et.al.
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- KINETIC CH ACIDITY AND FEATURES OF THE TRANSMISSION OF ELECTRONIC EFFECTS IN DIMETHYLPHENYLSULFONIUM SALTS
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1.Analysis of the parameters of the IR and NMR spectra of dimethylphenylsulfonium salts indicates the absence of the transmission of the electronic effects of meta and para substituents from the phenyl ring through the "onium" sulfur atom of sulfur to the methyl group. 2.Rate constants of the deuteroexchange of a number of meta- and para-substituted dimethylphenylsulfonium salts were determined, and it was shown that their values correlate with Hammett ? constants, which partially take account of the conjugation effect.The low transmission coefficients of the "onium" sulfur atom and the S, SO, and SO2 (M) heterobridges in isostructural bridge systems are explained by the "internal" stabilization of the MCH2- fragment in the transition state of the reaction. 3.Grounds are found for the view that the main cause of the appearance of electronic conductivity in the "onium" sulfur atom in the transition state of the deuteroexchange reaction is the partial planarization of the intermediately formed ylide.Factors involving the interaction of the substrate with the external medium play an auxiliary role in the changes in rate.
- Tupitsyn, I. F.,Zatsepina, N. N.
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p. 1468 - 1475
(2007/10/02)
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- 18O Isotope Effect in 13C Nuclear Magnetic Resonance Spectroscopy. 7. Hydrolysis of 2,2-Dimethyloxirane in Dilute Acid and by Microsomal Epoxide Hydratase
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The 18O isotope effect in 13C NMR spectroscopy affords an analytical technique that may be used to ascertain directly and simultaneously, in a continuous-assay mode, the position of bond cleavage, the rate of hydrolysis, and the extent of any accompanying oxygen exchange during the hydrolysis of oxiranes.The synthesis of 2,2-dimethyloxirane (isobutylene oxide) is described.The hydrolysis of this compound in dilute acid, by mouse liver microsomes (epoxide hydratase), and by homogeneous rat liver epoxide hydratase (EC 3.3.2.3) was studied by 13C NMR spectroscopy.The 18O isotope-induced shifts of the 13C resonances of the primary carbon atom and of the tertiary carbon atom in the oxirane are 0.031 and 0.042 ppm upfield, respectively.The corresponding isotope shifts in the product diol (2-methylpropane-1,2-diol) are 0.019 and 0.033 ppm respectively.Dilute-acid-catalyzed hydrolysis of the oxirane results in retention of the 18O label on the primary carbon atom with no accompanying oxygen exchange.The rates of nonenzymatic hydrolysis measured with this technique closely approximate the rates of hydrolysis measured previously by tedious mass spectral analysis.In contrast, when either mouse liver microsomes or homogeneous rat liver microsomal epoxide hydratase was incubated at pH 8 and 35 deg C with 2,2-dimethyloxirane, the hydrolysis product was 2-methylpropane-1,2-diol, consistent with enzyme-catalyzed hydrolytic attack at the primary carbon.Competing base-catalyzed hydrolysis of the oxirane under identical experimental conditions was much slower than the enzyme-catalyzed reactions.Although specific numerical values of kcat could not be obtained due to inability to saturate the enzymes, kcat for 2,2-dimethyloxirane must be significantly greater than that for styrene oxide.This study further illustrates the applicability of the 18O isotope effect in 13C NMR spectroscopy in simplifying the analysis of a variety of kinetic and stereochemical problems.
- Risley, John M.,Kuo, Fengjiun,Etten, Robert L. Van
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p. 1647 - 1652
(2007/10/02)
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- The Chemistry of 4-Mercaptoazetidin-2-ones. Part 1. Preparation and Properties of (3R,4R)-4-Mercapto-3-phenoxyacetamidoazetidin-2-one
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(3R,4R)-4-Mercapto-3-phenoxyacetamidoazetidin-2-one (4) has been prepared in good yield from the penicillin V-derived thiazoline-azetidinone (1).Alkylation and acylation led exclusively to S-substituted azetidinones.Reaction with dimethyl acetylenedicarboxylate in hexamethylphosphoramide gave, in addition to the expected dimethoxycarbonylvinylthioazetidinone (15), the C-4-epimer (18).The latter probably arises via the intermediacy of the azetinone (16).
- Osborne, Neal F.
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p. 146 - 149
(2007/10/02)
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- Methylation study of ribonucleosides, deoxyribonucleosides, and 2′-O-methylribonucleosides with trimethylsulphonium hydroxide and trimethylsulphonium iodide. Influence of the 2′-hydroxy-groups on the reactivity of the base moieties of ribonucleosides
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Methylations of the naturally occuring ribonucleoside (1), deoxyribonucleoside (2), and 2′-O-methylribonucleoside (3) were carried out using trimethylsulphonium hydroxide (Me3SOH) and trimethylsulphonium iodide (Me3Sl). The base moiety of (2) and (3) are more reactive than the corresponding base moiety of (1). The sites and extent of methylation of (2) are considerably different from those of (1), but are almost identical with those of (3). The reactivities of (1)-(3) are discussed in connection to an intramolecular interaction of the 2′-OH groups with the base moiety of (1). The methylating characteristics of Me 3SOH and Me3Sl are also described. The kinetics indicate an SN2 mechanism for methylation of nucleosides by Me 3S+ ions.
- Yamauchi, Kiyoshi,Nakagima, Toru,Kinoshita, Masayoshi
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p. 2787 - 2792
(2007/10/02)
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- Synthesis and preliminary pharmacological activity of aminoalkoxy isosteres of glycolate ester anticholinergics
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A series of 2-(N-substituted amino)alkoxy-1,1-diphenylethanols was synthesized and evaluated for anticholinergic activity. The compounds differ structurally from the glycolate ester-type anticholinergic compounds by the bioisosteric substitution of a methylene group for the ester carbonyl moiety. The esters which result from this change have increased lipophilicity compared to their ester isosteres. Compounds in the series have significant anticholinergic activity when tested on isolated rat jejunum or for their ability to inhibit perphenazine-induced catatonia in rats. Structure-activity relationships of the compounds are discussed.
- Fries,Andrako,Hudgins
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p. 1250 - 1254
(2007/10/05)
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