1906-79-2Relevant academic research and scientific papers
Dual functional ionic liquids as plasticisers and antimicrobial agents for medical polymers
Choi, Seong Ying,Rodriguez, Hector,Mirjafari, Arsalan,Gilpin, Deirdre F.,McGrath, Stephanie,Malcolm, Karl R.,Tunney, Michael M.,Rogers, Robin D.,McNally, Tony
, p. 1527 - 1535 (2011)
Contamination of medical devices with bacteria such as Meticillin resistant Staphylococcus aureus (MRSA) is of great clinical concern. Poly(vinyl chloride) is widely used in the production of medical devices, such as catheters. The flexibility of catheter tubing is derived from the addition of plasticisers. Here, we report the design of two dual functional ionic liquids, 1-ethylpyridinium docusate and tributyl(2-hydroxyethyl)phosphonium docusate, which uniquely provide a plasticising effect, and exhibit antimicrobial and antibiofilm-forming activity to a range of antibiotic resistant bacteria. The plasticisation of poly(vinyl chloride) was tailored as a function of ionic liquid concentration. The effective antimicrobial behaviour of both ionic liquids originates from the chemical structure of the anion or cation and is not limited to the length of the alkyl chain on the anion/cation. The design approach adopted will be useful in developing ionic liquids as multi-functional additives for polymers.
Study on thermophysical properties for aqueous solutions of ionic liquid N-ethyl-pyridine dicyanamide [C2py][DCA]
Xing, Nan Nan,Fan, Ben Han,Bu, Xiao Xue,Wei, Jie,Pan, Yi,Guan, Wei
, p. 390 - 395 (2016)
The IL (ionic liquid) [C2py][DCA] (N-ethyl-pyridine dicyanamide) was prepared and confirmed by 1H NMR (1H nuclear magnetic resonance) spectroscopy, 13C NMR (13C nuclear magnetic resonance) spectroscopy. The values of density and surface tension of the IL [C2py][DCA] and its aqueous solutions with various molalities were determined at T = (288.15 to 318.15) K. The values of the molar volume for aqueous solutions of [C2py][DCA], V, were calculated and increase with the increase of temperature and molarity. On the basis of thermodynamics, a semi-empirical model-molar surface Gibbs free energy model of the ionic liquid solution was put forward. It can be used to predict the surface tension and the predicted values of the surface tension for aqueous [C2py][DCA] are all most the same with the corresponding experimental ones. In terms of the concept of the molar surface Gibbs free energy, a new E?tv?s equation is obtained. Each parameter of the new equation has a clear physical meaning, energy dimension and is more convenient to use.
Effective conversion sucrose into 5-hydroxymethylfurfural by tyrosine in [Emim]Br
Su, Kunmei,Liu, Xin,Ding, Min,Yuan, Qiuju,Li, Zhenhuan,Cheng, Bowen
, p. 350 - 354 (2013)
In this study, the synthesis of 5-hydroxymethylfurfural (5-HMF) from sucrose was carried out in ionic liquids 1-ethyl-3-methylimidazolium bromide ([Emim]Br) catalyzed by amino acids, and tyrosine displays the best activity. Under the optimal reaction conditions, 76.0% yield of 5-HMF from sucrose was obtained at 160 C for 4 h. The uniquely effective activity of tyrosine for sucrose conversion into 5-HMF in [Emim]Br is mainly attributed to its two types of active sites, free base NH2 and dissociated H+ sites. The former one plays a crucial role in the isomerization of glucose to fructose, and the latter one is active in the hydrolysis of sucrose into monosaccharides and dehydration of generated fructose to 5-HMF. Furthermore, the presence of acidic phenol group in tyrosine also has the synergic catalytic effect on sucrose conversion. In addition, with the use of tyrosine catalyst, other carbohydrates to form 5-HMF were also tested, and the effects of solvent, reaction temperature and reaction time on sucrose conversion into 5-HMF were investigated in detail. A possible mechanism for this catalytic process has been proposed.
Direct catalytic conversion of glucose and cellulose
Li, Zhenhuan,Su, Kunmei,Ren, Jun,Yang, Dongjiang,Cheng, Bowen,Kim, Chan Kyung,Yao, Xiangdong
, p. 863 - 872 (2018)
Biomass product 5-hydroxymethylfurfural (5-HMF) can be used to synthesize a broad range of value added compounds currently derived from petroleum. Thus, the effective conversion of glucose or cellulose (the major components of biomass) into fuels and chemical commodities has been capturing increasing attention. Previous studies have been extensively focused on a two-step process for producing 5-HMF from glucose or cellulose, i.e., the isomerization of glucose into fructose and then the dehydration of fructose. We herein discovered that heterogeneous sulfonated poly(phenylene sulfide) (SPPS) containing strong Br?nsted acid sites is able to convert glucose and cellulose into 5-HMF with a high yield in ionic liquids (ILs). The optimal activity of glucose conversion to 5-HMF achieves a yield of 87.2% after 4 h reaction at 140 °C. For direct cellulose conversion, a 5-HMF yield of 68.2% can be achieved. The reaction mechanism over the SPPS catalyst in ILs was studied by DFT calculations, and the results indicated that the SO3H group of SPPS plays a crucial role in glucose conversion into 5-HMF, and it acts as a proton donor as a Br?nsted acid and functions as a proton acceptor as the conjugate base. Furthermore, the anions and cations of ILs together with SO3H-SPPS helped in stabilizing the reaction intermediates and transition states, which also resulted in glucose facile conversion into 5-HMF. The new catalyst system highlights new opportunities offered by optimizing the production of 5-HMF directly from glucose and cellulose.
Bromobismuthates: Cation-induced structural diversity and Hirshfeld surface analysis of cation–anion contacts
Adonin, Sergey A.,Gorokh, Igor D.,Novikov, Alexander S.,Samsonenko, Denis G.,Korolkov, Ilya V.,Sokolov, Maxim N.,Fedin, Vladimir P.
, p. 282 - 288 (2018)
Reactions of [BiBr6]3? and bromide salts of various substituted pyridinium cations in excess of HBr result in a series of bromobismuthate anionic complexes of various geometry and nuclearity: [{BiBr4}n]n?, [Bi2Br9]3? and [Bi2Br10]4?. Hirshfeld surface analysis for 19 crystal structure was performed; impact of various X-Br contacts on the crystal structures is discussed.
Thermochemistry of alkyl pyridinium bromide ionic liquids: Calorimetric measurements and calculations
Tong, Bo,Liu, Qing-Shan,Tan, Zhi-Cheng,Welz-Biermann, Urs
, p. 3782 - 3787 (2010)
Two ionic liquids, 1-ethylpyridinium bromide (EPBr) and 1-propylpyridinium bromide (PPBr), were prepared and the structures were characterized by 1H NMR. The thermodynamic properties of EPBr and PPBr were studied with adiabatic calorimetry (AC) and thermogravimatric analysis (TG-DTG). The heat capacity was precisely measured in the temperature range from 78 to 410 K by means of a fully automated adiabatic calorimeter. For EPBr, the melting temperature, enthalpy, and entropy of solid-liquid phase transition were determined to be 391.31 ± 0.28 K, 12.77 ± 0.09 kJ · mol-1, and 32.63 ± 0.22 J-K-1-mol-1, respectively, and for PPBr they were 342.83 ± 0.69 K, 10.97 ± 0.05 kJ-mol-1, and 32.00 ± 0.10 J-K-1TnOn-1, respectively. The thermodynamic functions (HT° - H 298.15°) and (ST° - S298.15°) were derived from the heat capacity data in the experimental temperature range with an interval of 5 K. The thermostablility of the compounds was further studied by TGA measurements. The phase change behavior and thermodynamic properties were compared and estimated in a series of alkyl pyridinium bromide ionic liquids. Results indicate that EPBr has higher melting and decomposition temperature, as well as phase transition enthalpy and entropy but lower heat capacity than PPBr due to their different molecular structures.
Targeted Synthesis of Trimeric Organic-Bromoplumbate Hybrids That Display Intrinsic, Highly Stokes-Shifted, Broadband Emission
Febriansyah, Benny,Neo, Chong Shern Daniel,Giovanni, David,Srivastava, Shivani,Lekina, Yulia,Koh, Teck Ming,Li, Yongxin,Shen, Ze Xiang,Asta, Mark,Sum, Tze Chien,Mathews, Nripan,England, Jason
, p. 4431 - 4441 (2020)
Zero-dimensional (0D) hybrid organic-inorganic lead halides have been shown to display efficient broadband photoluminescence and are, therefore, of significant interest for artificial lighting applications. However, work that investigates the formability of the materials as a function of templating organic cation structure is rare. This severely limits our ability to rationally design new materials displaying specific structural and photophysical properties. With the goal of accessing rare 0D trimeric bromoplumbates, we have systematically varied templating N-alkylpyridinium cations and examined their impact upon inorganic lattice structure. Whereas comparatively short and flexible N-alkyl substituents (ethyl, 2-hydroxyethyl, and pentyl) yield one-dimensional (1D) inorganic chains, more rigid substituents (benzyl, acetamidyl, and cyanomethyl) afford hybrids composed of lead bromide face-sharing trimers (i.e., [Pb3Br12]6-). Of the rigid substituents studied, benzyl groups were found to enforce the highest level of distortion of the [PbBr6]4- octahedra that comprise their trimeric structures. Upon exposure to ultraviolet (UV) light, N-benzylpyridinium lead bromide (1)6[Pb3Br12] exhibits a broadband emission, centered at 571 nm, which spans from 400 to 800 nm. More specifically, it displays a large Stokes shift of ca. 1.39 eV and a full width at half-maximum of ca. 146 nm. This broadband emission decays with a comparatively long lifetime of 426 ns at room temperature, which increases to 5.8 μs at 77 K. The reduced size and dimensionality of its inorganic lattice also result in a photoluminescence quantum yield (of at least 10%) that is approximately one order of magnitude higher than that of its 1D congeners. Mechanistically, broadband emission in (1)6[Pb3Br12] is believed to originate from triplet excited state(s) obtained from excited-state structural reorganization of the [Pb3Br12]6- moiety.
Density and surface tension of ionic liquids [Cnpy][NTf 2] (n = 2, 4, 5)
Liu, Qing-Shan,Yang, Miao,Yan, Pei-Fang,Liu, Xiu-Mei,Tan, Zhi-Cheng,Welz-Biermann, Urs
, p. 4928 - 4930 (2010)
Density and surface tension of the air- and water-stable hydrophobic ionic liquids N-alkylpyridinium bis(trifluoromethylsulfonyl)imide ([C npy][NTf2], n = 2, 4, 5) were measured in the temperature range T = (283.15 to 338.15) K. The melting temperatures of the samples were determined by differential scanning calorimetry (DSC). Decomposition temperatures are higher than 600 K as determined by thermogravimetric analysis (TG).
Boosting activity of molecular oxygen by pyridinium-based photocatalysts for metal-free alcohol oxidation
Ma, Shuai,Cui, Jing-Wang,Rao, Cai-Hui,Jia, Meng-Ze,Chen, Yun-Rui,Zhang, Jie
supporting information, p. 1337 - 1343 (2021/02/26)
An eco-friendly and economical approach for the photocatalytic oxidation of organic inter-mediates by air under mild conditions is highly desirable in green and sustainable chemistry, where the photogeneration of active oxygen species plays a key role in improving conversion efficiency and selectivity. By using pyridinium derivatives as molecular mediators for electron transfer and energy transfer, the simultaneous activation of O2from air into superoxide radicals and singlet oxygen species can be achieved, and a photoinduced electron transfer catalytic system for the oxidation of alcohols has been developed. Thus, we have successfully simplified the complicated catalytic system into a single molecular catalyst without any additional noble metals and co-catalysts/additives. The current photocatalytic system shows high catalytic efficiency not only for aromatic alcohols but also for aliphatic alcohols that are generally difficult to undergo aerobic oxidation at room temperature under air atmosphere, representing an ideal photocatalytic platform for green and economical organic syntheses.
ZIF-8-porous ionic liquids for the extraction of 2,2,3,3-tetrafluoro-1-propanol and water mixture
Wang, Zenghui,Zhao, Pingping,Wu, Jimin,Gao, Jun,Zhang, Lianzheng,Xu, Dongmei
supporting information, p. 8557 - 8562 (2021/05/26)
The design of stable ionic liquids (ILs) has become crucial for efficient liquid-liquid extraction (LLE) of alcohol and water. Porous ionic liquids (PILs), as a special class of ILs, have attracted attention by virtue of their unique porous structure and IL characteristics. In this research, a series of zeolitic imidazolate framework-8 based porous ionic liquids (ZIF-8-PILs) were synthesized by simply mixing a solution of zeolitic imidazolate framework-8 (ZIF-8) and rationally designed ILs. The introduction of ZIF-8 resulted in a unique liquid porous structure and molecular sieve for ZIF-8-PILs. The improved extraction properties endowed ZIF-8/[Bpy][NTf2] with more efficiency for the separation of 2,2,3,3-tetrafluoro-1-propanol (TFP) and water with 88.1% TFP extraction rate and steady reuse. The excellent extraction performance of ZIF-8-PILs is discussed in relation to their textural property and unique intermolecular interaction.
