5587-42-8Relevant academic research and scientific papers
Bifunctional temperature-sensitive amphiphilic acidic ionic liquids for preparation of biodiesel
Wu, Qin,Wan, Hualin,Li, Hansheng,Song, Haoran,Chu, Tonghua
, p. 74 - 79 (2013)
Several water-stable bifunctional temperature-sensitive amphiphilic Bronsted-acidic ionic liquids with an alkane sulfonic acid group and a polyether group were synthesized through polyethylene glycol monomethylether as raw material. The properties and structures of the ionic liquids were experimentally characterized. Esterification of oleic acid with methanol to biodiesel was investigated in various bifunctional temperature-sensitive amphiphilic acidic ionic liquids. The amphiphilicity, temperature-sensitive, polymerization degree, acidity and activity correlation for the ionic liquids were studied. It was found that their structures were consistent with the designed structure and their purities were high. Among all these ionic liquids, the ionic liquid - MPEG-350-ILs showed the best catalytic activity that is near to that of concentrated sulfuric acid, which is ascribed to its strong Bronsted acidity and amphiphilicity. The catalytic activity of each ILs is dependent on the polymerization degree of polyether cation. The catalytic activity decreased with lengthening polyether chain of ionic liquids. These ionic liquids exhibited temperature-sensitive property. The produced biodiesel could be separated via simple decantation and the ionic liquids could be reused.
A blue luminescent MOF as a rapid turn-off/turn-on detector for H2O, O2 and CH2Cl2, MeCN: 3 ∞ [Ce(Im)3ImH]·ImH
Meyer, L. V.,Sch?nfeld, F.,Zurawski, A.,Müller-Buschbaum, K.,Mai, M.,Feldmann, C.
, p. 4070 - 4079 (2015)
The blue emitting luminescent MOF 3∞[Ce(Im)3ImH]·ImH forms a 3D-framework with Kagom net topology. The framework exhibits an intense blue luminescence which can be retained upon activation of the MOF with the formula 3∞[Ce(Im)3ImH]. The luminescence is metal-based due to parity-allowed 5d-4f-transitions. Time-dependent investigations of the interaction with liquid and gas analytes show that the MOF-by utilising 5d-4f-transitions of Ce3+-can be used as a high-speed "turn-off" detector for water and oxygen in dry air. Other protic or polar solvents, like methanol, acetone or pyridine, which also show a "turn-off"-effect can be distinguished from water-detection either on a time scale (ranging up to 250000:1) or a shift of the chromaticity, the latter being pronounced for MeOH. The fast time-dependent decrease of the luminescence intensity for water arises from an extremely fast hydrolysis and is irreversible. Polar aprotic molecules like dichloromethane and acetonitrile can also result in a "turn-on"-effect of the luminescence intensity due to their behaviour as additional sensitizers for Ce3+-emission. We conclude that the cerium-MOF can be utilised in gas and liquid sensing applications as a detector material for water and oxygen in dry air. The luminescence is intense with good quantum yield between 55% (as-synthesised) and 36% (activated). This implies that only milligram amounts of the material are needed to detect the analyte species and is especially useful, as the MOF can be directly used as-synthesised for water detection in applications for which an irreversible signal change is desired, e.g. preventing a signal change upon unwanted re-drying.
Synthesis of 2, 2, 4-trimethyl-1, 3-pentaerediol monoisobutyrate catalyzed by homogeneous catalysis-liquid/liquid separation catalytic system based on Bibasic sites Ionic Liquids
Zhang, Shuying,Wang, Jiaomei,Liu, Xiangxue,Wang, Ke,Zhang, Chao,Song, Hongbing,Guo, Zhenmei,Lv, Zhiguo
, (2020)
Herein a novel homogeneous catalysis-liquid/liquid separation catalytic system based on 1, 8-diazabicyclo-[5.4.0] undec-7-ene (DBU)-functionalized, 1, 1, 3, 3-tetramethyl guanidine-functionalized and imidazolium-functionalized bibasic sites ionic liquids (BSILs) ([HDBU]IM, [Aemim]IM, [TMG]IM, [Aemim]Pro, [Aemim]Gly, [HDBU]Pro and [HDBU]Gly) with a room temperature liquid/liquid phase transition characteristic were reported. And for the first time, this novel catalytic system was employed for the synthesis of 2, 2, 4-trimethyl-1, 3-pentaerediol monoisobutyrate (CS-12), achieving homogeneous catalysis, easy recycling and long service-life of the catalyst. Additionally, the mechanism of homogeneous catalysis-biphasic separation might be explained by the solubility of reactant and product in BSILs/H2O catalytic system and the existence H-bonding between BSILs and H2O. Bibasic sites were confirmed by two endothermic peaks on the TG-DCS curve of [Aemim]IMC (the CO2 captured by [Aemim]IM).
Trimeric Supra-Amphiphile with Diverse Lamellar Self-Assemblies
Li, Jun,Li, Hui,Wang, Jie,Jiang, Hongshi,Yao, Chenzhong,Wang, Gaofeng,Ma, Huixuan,Shi, Lijuan
, p. 209 - 216 (2019)
A new kind of trimeric supra-amphiphile [M-4-M-4-M][DBS]3 that exhibits diverse self-assembly behaviours was fabricated through ion exchange between linear tricationic imidazolium chloride ([M-4-M-4-M]Cl3) and sodium dodecyl benzene sulfonate (SDBS). Micelles are spontaneously transformed into unilamellar vesicles at a quite low concentration (1.5 mM), and then evolved to multilamellar vesicles and planar bilayers successively with a further increase in the concentration of [M-4-M-4-M][DBS]3 in the absence of any additives. The presence of π-π stacking interactions has been proved to promote the lamellar arrangement of the supra-amphiphile. With increasing temperatures, [M-4-M-4-M][DBS]3 exhibits interesting “clouding” and phase separation in the La phase, behaving like common nonionic surfactants. Chain-like aggregates are formed in the bottom phase, which are probably induced by the hierarchical assembly of vesicles. This work provides useful insights into the role of weak interactions in the fabrication and self-assembly of oligomeric supra-amphiphiles, and paves a way to enrich the structures and functions of self-assemblies.
Copper(I)-mediated CN/CC bond-forming reaction with tetrafluoroethylene for the synthesis of N-fluoroalkyl heteroarenes via an azacupration/coupling mechanism
Ishida, Naoyoshi,Adachi, Takuya,Iwamoto, Hiroaki,Ohashi, Masato,Ogoshi, Sensuke
supporting information, p. 442 - 444 (2021/03/15)
A novel copper(I)-mediated CN/CC bond-forming reaction involving tetrafluoroethylene (TFE), imidazolide or benz-imidazolide salts, and aryl iodides has been developed. This three-component coupling reaction can provide highly functionalized N-fluoroalkyl heteroaromatic compounds in up to 98% yield via a one-pot procedure. The azacupration of TFE with the copper(I) imidazolide species to afford the fluoroalkylcopper(I) complex is the key process in the transformation.
Ruthenium complex immobilized on supported ionic-liquid-phase (SILP) for alkoxycarbonylation of olefins with CO2
Xia, Shi-Ping,Ding, Guang-Rong,Zhang, Rui,Han, Li-Jun,Xu, Bao-Hua,Zhang, Suo-Jiang
supporting information, p. 3073 - 3080 (2021/05/05)
In this study, the heterogeneously catalyzed alkoxycarbonylation of olefins with CO2based on a supported ionic-liquid-phase (SILP) strategy is reported for the first time. An [Ru]@SILP catalyst was accessed by immobilization of ruthenium complex on a SILP, wherein imidazolium chloride was chemically integrated at the surface or in the channels of the silica gel support. An active Ru site was generated through reacting Ru3(CO)12with the decorated imidazolium chloride in a proper microenvironment. Different IL films, by varying the functionality of the side chain at the imidazolium cation, were found to strongly affect the porosity, active Ru sites, and CO2adsorption capacity of [Ru]@SILP, thereby considerably influencing its catalytic performance. The optimized [Ru]@SILP-A-2 displayed enhanced catalytic performance and prominent substrate selectivity compared to an independent homogeneous system under identical conditions. These findings provide the basis for a novel design concept for achieving both efficient and stable catalysts in the coupling of CO2with olefins.
Iridium and ruthenium complexes of N-heterocyclic carbene- and pyridinol-derived chelates as catalysts for aqueous carbon dioxide hydrogenation and formic acid dehydrogenation: The role of the alkali metal
Siek, Sopheavy,Burks, Dalton B.,Gerlach, Deidra L.,Liang, Guangchao,Tesh, Jamie M.,Thompson, Courtney R.,Qu, Fengrui,Shankwitz, Jennifer E.,Vasquez, Robert M.,Chambers, Nicole,Szulczewski, Gregory J.,Grotjahn, Douglas B.,Webster, Charles Edwin,Papish, Elizabeth T.
, p. 1091 - 1106 (2017/12/08)
Hydrogenation reactions can be used to store energy in chemical bonds, and if these reactions are reversible, that energy can be released on demand. Some of the most effective transition metal catalysts for CO2 hydrogenation have featured pyridin-2-ol-based ligands (e.g., 6,6'-dihydroxybipyridine (6,6'-dhbp)) for both their proton-responsive features and for metal-ligand bifunctional catalysis. We aimed to compare bidentate pyridin-2-ol based ligands with a new scaffold featuring an N-heterocyclic carbene (NHC) bound to pyridin-2-ol. Toward this aim, we have synthesized a series of [CpIr(NHC-pyOR)Cl]OTf complexes where R = tBu (1), H (2), or Me (3). For comparison, we tested analogous bipyderived iridium complexes as catalysts, specifically [CpIr(6,6'-dxbp)Cl]OTf, where x = hydroxy (4Ir) or methoxy (5Ir); 4Ir was reported previously, but 5Ir is new. The analogous ruthenium complexes were also tested using [(η6-cymene)Ru(6,6'-dxbp)Cl]OTf, where x = hydroxy (4Ru) or methoxy (5Ru); 4Ru and 5Ru were both reported previously. All new complexes were fully characterized by spectroscopic and analytical methods and by single-crystal X-ray diffraction for 1, 2, 3, 5Ir, and for two [Ag(NHC-pyOR)2]OTf complexes 6 (R = tBu) and 7 (R = Me). The aqueous catalytic studies of both CO2 hydrogenation and formic acid dehydrogenation were performed with catalysts 1-5. In general, NHC-pyOR complexes 1-3 were modest precatalysts for both reactions. NHC complexes 1-3 all underwent transformations under basic CO2 hydrogenation conditions, and for 3, we trapped a product of its transformation, 3SP, which we characterized crystallographically., we trapped a product of its transformation, 3SP, which we characterized crystallographically.. For CO2 hydrogenation with base and dxbp-based catalysts, we observed that x = hydroxy (4Ir) is 5-8 times more active than x = methoxy (5Ir). Notably, ruthenium complex 4Ru showed 95% of the activity of 4Ir. For formic acid dehydrogenation, the trends were quite different with catalytic activity showing 4Ir Z> 4Ru and 4Ir ≈ 5Ir Secondary coordination sphere effects are important under basic hydrogenation conditions where the OH groups of 6,6'-dhbp are deprotonated and alkali metals can bind and help to activate CO2. Computational DFT studies have confirmed these trends and have been used to study the mechanisms of both CO2 hydrogenation and formic acid dehydrogenation.
Liquid Nickel Salts: Synthesis, Crystal Structure Determination, and Electrochemical Synthesis of Nickel Nanoparticles
Sniekers, Jeroen,Verguts, Ken,Brooks, Neil R.,Schaltin, Stijn,Phan, Thanh Hai,Trung Huynh, Thi Mien,Van Meervelt, Luc,Defeyter, Steven,Seo, Jin Won,Fransaer, Jan,Binnemans, Koen
, p. 1010 - 1020 (2016/01/16)
New nickel-containing ionic liquids were synthesized, characterized and their electrochemistry was investigated. In addition, a mechanism for the electrochemical synthesis of nanoparticles from these compounds is proposed. In these so-called liquid metal salts, the nickel(II) cation is octahedrally coordinated by six N-alkylimidazole ligands. The different counter anions that were used are bis(trifluoromethanesulfonyl)imide (Tf2N-), trifluoromethanesulfonate (OTf-) and methanesulfonate (OMs-). Several different N-alkylimidazoles were considered, with the alkyl sidechain ranging in length from methyl to dodecyl. The newly synthesized liquid metal salts were characterized by CHN analysis, FTIR, DSC, TGA and viscosity measurements. An odd-even effect was observed for the melting temperatures and viscosities of the ionic liquids, with the complexes with an even number of carbon atoms in the alkyl chain of the imidazole having a higher melting temperature and a lower viscosity than the complexes with an odd number of carbons. The crystal structures of several of the nickel(II) complexes that are not liquid at room temperature were determined. The electrochemistry of the compounds with the lowest viscosities was investigated. The nickel(II) cation could be reduced but surprisingly no nickel deposits were obtained on the electrode. Instead, nickel nanoparticles were formed at 100 % selectivity, as confirmed by TEM. The magnetic properties of these nanoparticles were investigated by SQUID measurements.
Zn-based ionic liquids as highly efficient catalysts for chemical fixation of carbon dioxide to epoxides
Liu, Mengshuai,Wang, Fangxiao,Shi, Lei,Liang, Lin,Sun, Jianmin
, p. 14277 - 14284 (2015/03/05)
The novel Zn-based task-specific ionic liquids (Zn-TSILs) catalysts were developed for the coupling of carbon dioxide and epoxides to form cyclic carbonates under mild reaction conditions without using additional organic solvents and cocatalysts. Due to the synergistic effects of the cation and anion in this catalytic system, excellent yields and selectivities to cyclic carbonates were achieved with high TOF values up to 794 h-1. Among the catalysts investigated, OH-containing Zn-TSILs showed better activity than COOH-containing Zn-TSILs, and [(CH2CH2OH)Bim]ZnBr3 was found to be the best. Additionally, the influences of CO2 pressure and catalyst concentration were also investigated over [(CH2CH2OH)Bim]ZnBr3. In addition, the rate constants as well as the activation energies for the cycloaddition reaction catalyzed by Zn-TSIL and TSIL were comparatively determined. The activation energy was calculated to be 34.1 kJ mol-1 for bare TSIL catalyst, whereas the Zn-TSIL reduced the activation energy value by 14.7 kJ mol-1. Moreover, the Zn-TSIL was easily recyclable without significant loss of activity, representing the exceptionally promising candidate for the effective fixation of CO2 to epoxides.
Synthesis and characterization of copper(II) complexes incorporating pyrazolyl-derived N,S-donor bidentate ligands
Sadr, Moayad Hossaini,Soltani, Behzad,Jalili, Alireza,Nejadghafar, Faeghe,Kia, Reza,Engle, James T.,Ziegler, Christopher J.
, p. 611 - 617 (2013/01/15)
The novel bidentate N,S-donor anionic ligands [PhNCSIndz]-, [PhNCSImz]-, [PhNCSPzMe3]-, and [EtNCSPz]-, where Indz = indazole, Imz = imidazole, PzMe3 = 3,4,5-trimethylpyrazole, and Pz = pyrazole, were synthesized and used
