36432-31-2Relevant articles and documents
Effect of methyl groups onto imidazolium cation ring on liquid crystallinity and ionic conductivity of amphiphilic ionic liquids
Mukai, Tomohiro,Yoshio, Masafumi,Kato, Takashi,Ohno, Hiroyuki
, p. 1630 - 1631 (2004)
Phase transition behavior of imidazolium dodecylsulfonate was considerably affected by the introduction of methyl groups onto the imidazolium cation ring. Methyl group on the 2-position eliminated the liquid crystallinity. That on the 4-position was effective to suppress the crystallization. Copyright
Confined water in imidazolium based ionic liquids: A supramolecular guest@host complex case
Zanatta, Marcileia,Girard, Anne-Lise,Marin, Graciane,Ebeling, Gunter,Dos Santos, Francisco P.,Valsecchi, Chiara,Stassen, Hubert,Livotto, Paolo R.,Lewis, William,Dupont, Jairton
, p. 18297 - 18304 (2016)
It is well known that the macroscopic physico-chemical properties of ionic liquids (ILs) are influenced by the presence of water that strongly interferes with the supramolecular organization of these fluids. However, little is known about the function of water traces within this confined space and restricted ionic environments, i.e. between cations and anions. Using specially designed ILs namely 1,2,3-trimethyl-1H-imidazol-3-ium imidazol-1-ide (MMMI·Im) and 3-n-butyl-1,2-dimethyl-1H-imidazol-3-ium imidazol-1-ide (BMMI·Im), the structure and function of water have been determined in condensed, solution and gas phases by X-ray diffraction studies, NMR, molecular dynamics simulations (MDS) and DFT calculations. In the solid state the water molecule is trapped inside the ionic network (constituted of contact ion pairs formed by π+-π- interaction) through strong H-bonds involving the water hydrogens and the nitrogens of two imidazolate anions forming a guest@host supramolecular structure. A similar structural arrangement was corroborated by DFT calculations and MDS. The presence of a guest@host species (H2O@ILpair) is maintained to a great extent even in solution as detected by 1H-1H NOESY-experiments of the ILs dissolved in solvents with low and high dielectric constants. This confined water catalyses the H/D exchange with other substrates containing acidic-H such as chloroform.
Twisted Push-Pull Alkenes Bearing Geminal Cyclicdiamino and Difluoroaryl Substituents
Kundu, Abhinanda,Chandra, Shubhadeep,Mandal, Debdeep,Neuman, Nicolás I.,Mahata, Alok,Anga, Srinivas,Rawat, Hemant,Pal, Sudip,Schulzke, Carola,Sarkar, Biprajit,Chandrasekhar, Vadapalli,Jana, Anukul
, p. 12683 - 12692 (2021/09/18)
The systematic combination of N-heterocyclic olefins (NHOs) with fluoroarenes resulted in twisted push-pull alkenes. These alkenes carry electron-donating cyclicdiamino substituents and two electron-withdrawing fluoroaryl substituents in the geminal posit
Crystal structure, magneto-structural correlation, thermal and electrical studies of an imidazolium halometallate molten salt: (trimim)[FeCl4]
Beobide, Garikoitz,Cano, Israel,De Pedro, Imanol,Fabelo, Oscar,Fernández, Jesús Rodríguez,Fernández-Díaz, María Teresa,González-Izquierdo, Palmerina,Ruiz De Larramendi, Idoia,Vallcorba, Oriol
, p. 11200 - 11209 (2020/04/03)
A novel imidazolium halometallate molten salt with formula (trimim)[FeCl4] (trimim: 1,2,3-trimethylimidazolium) was synthetized and studied with structural and physico-chemical characterization. Variableerature synchrotron X-ray powder diffraction (SXPD) from 100 to 400 K revealed two structural transitions at 200 and 300 K. Three different crystal structures were determined combining single crystal X-ray diffraction (SCXD), neutron powder diffraction (NPD), and SXPD. From 100 to 200 K, the compound exhibits a monoclinic crystal structure with space group P21/c. At 200 K, the former crystal system and space group are retained, but a disorder in the organic cations is introduced. Above 300 K, the structure transits to the orthorhombic space group Pbcn, retaining the crystallinity up to 400 K. The study of the thermal expansion process in this temperature range showed anisotropically evolving cell parameters with an axial negative thermal expansion. Such an induction occurs immediately after the crystal phase transition due to the translational and reorientational dynamic displacements of the imidazolium cation within the crystal building. Electrochemical impedance spectroscopy (EIS) demonstrated that this motion implies a high and stable solid-state ionic conduction (range from 4 × 10-6 S cm-1 at room temperature to 5.5 × 10-5 S cm-1 at 400 K). In addition, magnetization and heat capacity measurements proved the presence of a three-dimensional antiferromagnetic ordering below 3 K. The magnetic structure, determined by neutron powder diffraction, corresponds to ferromagnetic chains along the a-axis, which are antiferromagnetically coupled to the nearest neighboring chains through an intricate network of superexchange pathways, in agreement with the magnetometry measurements.
Synthesis of new hetero-arylidene-9(10H)-anthrone derivatives and their biological evaluation
Baptista, Pedro V.,Branco, Paula S.,Fernandes, Alexandra R.,Malta, Gabriela,Peixoto, Daniela,Roma-Rodrigues, Catarina,Ferreira, Luísa M.
, (2020/04/22)
New hetero-arylidene-9(10H)-anthrone derivatives (1) were synthesized from reaction of 1,2-dimethyl-3-alkyl imidazolium salts (2) and 9-anthracenecarboxaldehyde. Ion exchange of the anion with dioctyl sulfosuccinate and lithium bis(trifluoromethanesulfonyl)imide led to the preparation of other derivatives. The antiproliferative effect of the compounds was evaluated in human ovarian (A2780) and colorectal (HCT116) carcinoma cell lines and in normal primary human fibroblasts. Compound 1 presented an antiproliferative effect related to the imidazolium pattern of substitution with compounds having a decyl group at the R-position (1c and 3c) showing the highest cytotoxic activities in all cell lines independently of the counter ion. Compounds 1b and 1c internalize A2780 cancer cells via a passive or an active transport, respectively, inducing A2780 cell death via an extrinsic apoptosis (1b) or intrinsic apoptosis and oncosis (1c). The localization of both compounds in the cytoplasm coupled to the absence of reactive oxygen species (ROS) induction suggest that the mechanisms of toxicity might be different than those of other anthracyclines currently used in chemotherapy.
Efficient synthesis of aluminosilicate RTH zeolite with good catalytic performances in NH3-SCR and MTO reactions
Xu, Hao,Wu, Qinming,Chu, Yueying,Jiang, Jingang,Zhang, Ling,Pan, Shuxiang,Zhang, Changsheng,Zhu, Longfeng,Deng, Feng,Meng, Xiangju,Maurer, Stefan,McGuire, Robert,Parvulescu, Andrei-Nicolae,Müller, Ulrich,Xiao, Feng-Shou
, p. 8705 - 8711 (2018/05/23)
2,6-methyl-N-methylpyridinium, as a novel organic template, is employed for the synthesis of RTH aluminosilicate zeolite with a SiO2/Al2O3 ratio of 17.6. The amount of 2,6-methyl-N-methylpyridinium template, the Na2O/SiO2 ratio, the SiO2/Al2O3 ratio, and the H2O/SiO2 ratio in the starting gel significantly influence the crystallization of RTH zeolite. Several analytical methods such as XRD, SEM, N2 sorption, TG-DTA, DRIFT and NMR were employed for the characterisation of the obtained RTH zeolites and to understand the crystallization process with the new template. Very interestingly, the crystallization of RTH zeolite with the new template takes a very short time (12 h at 130 °C and 50 min at 240 °C) compared with conventional RTH zeolite synthesis reported in the literature (72 h at 130 °C). Theoretical calculations show that this novel organic template has lower interaction energies for zeolite cage space filling than those of the organic templates previously reported in the literature, which lead to stronger structural directing. Kinetic results show that the activation energy of this novel organic template is much lower than that of the traditional one. Catalytic tests show that copper exchanged RTH zeolite (Cu-RTH) exhibits good catalytic properties in the NH3-SCR reaction and the H-RTH zeolite catalyst has excellent selectivities for ethylene and propylene in MTO reactions.
N-Heterocyclic olefins as efficient phase-transfer catalysts for base-promoted alkylation reactions
Blümel, Marcus,Crocker, Reece D.,Harper, Jason B.,Enders, Dieter,Nguyen, Thanh V.
supporting information, p. 7958 - 7961 (2016/07/06)
N-Heterocyclic olefins (NHOs) have very recently emerged as efficient promoters for several chemical reactions due to their strong Br?nsted/Lewis basicities. Here we report the novel application of NHOs as efficient phase-transfer organocatalysts for synt
Synthesis of RTH-type zeolites using a diverse library of imidazolium cations
Schmidt, Joel E.,Deimund, Mark A.,Xie, Dan,Davis, Mark E.
, p. 3756 - 3762 (2015/06/08)
RTH-type zeolites are promising catalytic materials for applications that include the important methanol-to-olefins (MTO) and NOX reduction reactions. Here, RTH-type zeolites are prepared using a wide-range of imidazolium-based, cationic organic structure directing agents (OSDAs), that greatly expand the methodologies and compositions that can be used to synthesize these materials. The abilities of the OSDAs to produce RTH-type zeolites agree well with results from molecular modeling studies of predicted stabilization energies of the OSDAs in the RTH framework. The RTH-type zeolites are stable to steaming up to 900 °C and are shown to be active MTO catalysts.
Highly stable N3-substituted imidazolium-based alkaline anion exchange membranes: Experimental studies and theoretical calculations
Gu, Fenglou,Dong, Huilong,Li, Youyong,Si, Zhihong,Yan, Feng
, p. 208 - 216 (2014/02/14)
Imidazolium cations with various N3-substituents (including methyl, butyl, heptyl, dodecyl, isopropyl, and diphenylmethyl groups) were synthesized and investigated in terms of their alkaline stability. The effect of the N3-substituent on the alkaline stab
Fast CO2 sequestration, activation, and catalytic transformation using N -heterocyclic olefins
Wang, Yan-Bo,Wang, Yi-Ming,Zhang, Wen-Zhen,Lu, Xiao-Bing
supporting information, p. 11996 - 12003 (2013/09/02)
N-Heterocyclic Olefin (NHO) with high electronegativity at the terminal carbon atom was found to show a strong tendency for CO2 sequestration, affording a CO2 adduct (NHO-CO2). X-ray single crystal analysis revealed the bent geometry of the binding CO2 in the NHO-CO2 adducts with an O-C-O angle of 127.7-129.9, dependent on the substitute groups of N-heterocyclic ring. The length of the C carboxylate-CNHO bond is in the range of 1.55-1.57 A, significantly longer than that of the Ccarboxylate-C NHC bond (1.52-1.53 A) of the previously reported NHC-CO 2 adducts. The FTIR study by monitoring the ν(CO2) region of transmittance change demonstrated that the decarboxylation of NHO-CO2 adducts is easier than that of the corresponding NHC-CO 2 adducts. Notably, the NHO-CO2 adducts were found to be highly active in catalyzing the carboxylative cyclization of CO2 and propargylic alcohols at mild conditions (even at ambient temperature and 0.1 MPa CO2 pressure), selectively giving α-alkylidene cyclic carbonates in good yields. The catalytic activity is about 10-200 times that of the corresponding NHC-CO2 adducts at the same conditions. Two reaction paths regarding the hydrogen at the alkenyl position of cyclic carbonates coming from substrate (path A) or both substrate and catalyst (path B) were proposed on the basis of deuterium labeling experiments. The high activity of NHO-CO2 adduct was tentatively ascribed to its low stability for easily releasing the CO2 moiety and/or the desired product, a possible rate-limiting step in the catalytic cycle.
