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Ivn Brito Joselyn Albanez Michael Bolte Alejandro Crdenas 《Acta Crystallographica. Section C, Structural Chemistry》2010,66(9):o466-o468
The title compound, C12H8N2O6S2, (I), is a positional isomer of S‐(2‐nitrophenyl) 2‐nitrobenzenethiosulfonate [Glidewell, Low & Wardell (2000). Acta Cryst. B 56 , 893–905], (II). The most obvious difference between the two isomers is the rotation of the nitro groups with respect to the planes of the adjacent aryl rings. In (I), the nitro groups are only slightly rotated out of the plane of the adjacent aryl ring [2.4 (6) and 6.7 (7)°], while in (II) the nitro groups are rotated by between 37 and 52°, in every case associated with S—S—C—C torsion angles close to 90°. Other important differences between the isomers are the C—S—S(O2)—C torsion angle [78.39 (2)° for (I) and 69.8 (3)° for (II) (mean)] and the dihedral angles between the aromatic rings [12.3 (3)° for (I) and 28.6 (3)° for (II) (mean)]. There are two types of C—H...O hydrogen bond in the structure [C...O = 3.262 (7) Å and C—H...O = 144°; C...O = 3.447 (7) Å and C—H...O = 166°] and these link the molecules into a two‐dimensional framework. The hydrogen‐bond‐acceptor properties differ between the two isomers. 相似文献
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Christopher Glidewell John N. Low Janet M. S. Skakle James L. Wardell 《Acta Crystallographica. Section C, Structural Chemistry》2002,58(8):o485-o486
The structure of the title compound, C12H8N2O4S2, contains no direction‐specific intermolecular interactions, i.e. no C—H?O hydrogen bonds, no aromatic π–π‐stacking interactions and no C—H?π(arene) interactions. This behaviour is compared with the three known symmetrical isomers of bis(nitrophenyl) disulfide, having the nitro groups on the two 2‐, 3‐ or 4‐positions, all of which exhibit direction‐specific supramolecular aggregation. 相似文献
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A novel preparation of 4‐phenylquinoline derivatives through acid‐catalyzed Friedländer reaction in ionic liquid ([bmim][BF4]) is described. The preparative procedure presented in this paper is operationally simple and environmentally benign. The reaction media and the catalyst used can be recovered and reused for at least four times without loss in the catalytic activity. 相似文献
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Vera Yu. Petukhova Leonid L. Fershtat Vadim V. Kachala Vladimir V. Kuznetsov Dmitriy V. Khakimov Tatyana S. Pivina Nina N. Makhova 《Journal of heterocyclic chemistry》2013,50(2):326-336
An interaction of 1,2‐dialkyldiaziridine and 1,2,3‐trialkyldiaziridine with methyl propiolate was studied both in organic solvent (MeCN, CH2Cl2, C6H6) and in ionic liquids. Earlier unknown linear structures, in which three molecules of methyl propiolate were suited to one diaziridine molecule (adducts 1 : 3), were obtained in MeCN. The diaziridine ring expansion products 1,2,3,4‐tetrahydropyrimidine derivatives (adducts 1 : 2) and, along with them in some cases, the same linear structures were obtained in ionic liquids. A mechanism of reactions found was offered. The regioselectivity of reactions was supposed to determine by the structure of substituents in initial diaziridines. This conclusion was supported by quantum chemical calculations. 相似文献
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Vakhitova L. N. Popov A. F. Burdina Ya. F. Savelova V. A. Belousova I. A. 《Theoretical and Experimental Chemistry》2004,40(4):226-233
It was shown that a distribution-type kinetic model can be used to describe the mechanism of the phase-transfer catalytic aminolysis of 4-nitrophenyl acetate with potassium glycinate in chlorobenzene with 18-crown-6 as catalyst. A quantitative assessment was made of the contributions from the reactions in the volume and at the interface in the solid/liquid system. 相似文献
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Sarah Khler Tim Liebert Michael Schbitz Jens Schaller Frank Meister Wolfgang Günther Thomas Heinze 《Macromolecular rapid communications》2007,28(24):2311-2317
The homogeneous conversion of cellulose in the ionic liquid 1‐ethyl‐3‐methylimidazolium acetate with 2‐furoyl chloride, p‐toluenesulfonyl chloride, and triphenylmethyl chloride yields surprisingly pure cellulose acetate samples in any case. From NMR spectroscopic studies, it may be concluded that during the homogeneous functionalization reactive intermediates including furane‐2‐carboxylic acid/acetic acid anhydride and acetic acid triphenylmethyl ester are formed leading to the cellulose acetates with DS values in the range from 0.55 to 1.86.
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Vakhitova L. N. Savelova V. A. Burdina Ya. F. Belousova I. A. Popov A. F. 《Russian Journal of Organic Chemistry》2003,39(7):968-971
In the phase-transfer system solid potassium aminoacetate-crown ether-chlorobenzene, the fraction of the nucleophile-catalyst complex trasferred to the organic phase does not exceed 1% of the amount of the solid phase. Nevertheless, the reactivity of the crown ether complex with potassium aminoacetate is sufficient to ensure the aminolysis to proceed in the organic phase at an appreciable rate. 相似文献
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用密度泛函理论考察了甲基咪唑和一系列的卤代烷烃(氯乙烷,氯丁烷,溴乙烷,溴丁烷)反应合成咪唑类离子液体的反应机理. 在B3LYP/6-31++G**//B3LYP/6-31G*基组水平上找到了两条反应路径:路径A(反应物→TS1→P1)和路径B(反应物→TS2→P2). 在路径A中, 卤素离子和咪唑环C2上的氢质子形成氢键;在路径B中, 卤素离子和咪唑环C5上的氢质子形成氢键. 计算发现, 氢键的形成在反应中起到了非常重要的作用, 特别是咪唑环C2上的氢质子在和卤素离子成氢键后形成了一个五员环结构的过渡态, 该过渡态能量较低. 经过渡态TS1的反应途径其活化能要低于经过渡态TS2的反应途径, 反应路径A为主要的反应通道. 计算结果表明, 经过渡态TS1的反应途径是一放热过程, 这和实验观察现象一致. 相似文献
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Haixiang Gao Dr. Young‐Hyuk Joo Dr. Brendan Twamley Dr. Zhiqiang Zhou Prof. Dr. Jean'ne M. Shreeve Prof. Dr. 《Angewandte Chemie (International ed. in English)》2009,48(15):2792-2795
No flame, no gain : A hypergolic mixture is composed of stable species that readily react/ignite on molecular contact. Both the anion and the cation in an ionic liquid play prominent roles in determining hypergolic properties as well as ignition delay times. With the 2,2‐dialkyltriazanium cation, salts with nitrate, chloride, nitrocyanamide, and dicyanamide anions are hypergolic.
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Timm Bergholz Dr. Benjamin Oelkers Dr. Benedikt Huber Prof. Bernhard Roling Prof. Dr. Jörg Sundermeyer 《Chemistry (Weinheim an der Bergstrasse, Germany)》2015,21(6):2613-2620
New salts based on imidazolium, pyrrolidinium, phosphonium, guanidinium, and ammonium cations together with the 5‐cyanotetrazolide anion [C2N5]? are reported. Depending on the nature of cation–anion interactions, characterized by XRD, the ionic liquids (ILs) have a low viscosity and are liquid at room temperature or have higher melting temperatures. Thermogravimetric analysis, cyclic voltammetry, viscosimetry, and impedance spectroscopy display a thermal stability up to 230 °C, an electrochemical window of 4.5 V, a viscosity of 25 mPa s at 20 °C, and an ionic conductivity of 5.4 mS cm?1 at 20 °C for the IL 1‐butyl‐1‐methylpyrrolidinium 5‐cyanotetrazolide [BMPyr][C2N5]. On the basis of these results, the synthesized compounds are promising electrolytes for lithium‐ion batteries. 相似文献
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《Electroanalysis》2006,18(23):2290-2296
Carbon powder has been functionalized with 2‐methoxy‐4‐nitrophenyl groups by the reduction of 2‐methoxy‐4‐nitrobenzenediazonium‐1,5‐naphthalenedisulfonate salt in presence of hypophosporous acid as a reducing agent. This provides an easy and inexpensive methodology to modify the carbon particle surface. This derivatization is carried out in the presence of 2‐methoxy‐4‐nitrobenzenediazonium 1,5‐naphthalenedisulfonate salt along with the carbon powder and hypophosporous acid. The electrochemical behavior of the resulting 2‐methoxy‐4‐nitrophenyl functionalized carbon powder was characterized by immobilizing it onto basal plane pyrolytic graphite (bppg) electrode and studying its voltammetric behavior. The surface morphology of derivatized carbon powder has been examined by SEM studies which revealed that the size of the functionalized carbon particles are larger than bare carbon particles The effect of pH on peak potentials, scan rate and stability of the functionalized carbon particles has revealed that they are surface bound species. 相似文献
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Prof. Duncan W. Bruce Prof. Yanan Gao Prof. José Nuno Canongia Lopes Dr. Karina Shimizu Dr. John M. Slattery 《Chemistry (Weinheim an der Bergstrasse, Germany)》2016,22(45):16113-16123
Liquid‐crystalline ionic liquids (LCILs) are ordered materials that have untapped potential to be used as reaction media for synthetic chemistry. This paper investigates the potential for the ordered structures of LCILs to influence the stereochemical outcome of the Diels–Alder reaction between cyclopentadiene and methyl acrylate. The ratio of endo‐ to exo‐product from this reaction was monitored for a range of ionic liquids (ILs) and LCILs. Comparison of the endo:exo ratios in these reactions as a function of cation, anion and liquid crystallinity of the reaction media, allowed for the effects of liquid crystallinity to be distinguished from anion effects or cation alkyl chain length effects. These data strongly suggest that the proportion of exo‐product increases as the reaction media is changed from an isotropic IL to a LCIL. A detailed molecular dynamics (MD) study suggests that this effect is related to different hydrogen bonding interactions between the reaction media and the exo‐ and endo‐transition states in solvents with layered, smectic ordering compared to those that are isotropic. 相似文献
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Diels‐Alder reactions in a number of air‐ and moisture‐stable dialkylimidazolium halide‐ZnCl2 ionic liquids are reported. High yields and high endo selectivities have been observed. The ionic liquids could then be recyclable without loss of reactivity. 相似文献
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Encapsulated Ionic Liquids for CO2 Capture: Using 1‐Butyl‐methylimidazolium Acetate for Quick and Reversible CO2 Chemical Absorption. 下载免费PDF全文
Cristian Moya Prof. Noelia Alonso‐Morales Prof. Miguel A. Gilarranz Prof. Juan J. Rodriguez Prof. Jose Palomar 《Chemphyschem》2016,17(23):3891-3899
The potential advantages of applying encapsulated ionic liquid (ENIL) to CO2 capture by chemical absorption with 1‐butyl‐3‐methylimidazolium acetate [bmim][acetate] are evaluated. The [bmim][acetate]‐ENIL is a particle material with solid appearance and 70 % w/w in ionic liquid (IL). The performance of this material as CO2 sorbent was evaluated by gravimetric and fixed‐bed sorption experiments at different temperatures and CO2 partial pressures. ENIL maintains the favourable thermodynamic properties of the neat IL regarding CO2 absorption. Remarkably, a drastic increase of CO2 sorption rates was achieved using ENIL, related to much higher contact area after discretization. In addition, experiments demonstrate reversibility of the chemical reaction and the efficient ENIL regeneration, mainly hindered by the unfavourable transport properties. The common drawback of ILs as CO2 chemical absorbents (low absorption rate and difficulties in solvent regeneration) are overcome by using ENIL systems. 相似文献