A series of heterogemini imidazolium surfactants with two-methylene spacer groups （[Cm- 2-Cnim]Br2, m, n=8, 10, 12, 14, 16; m≠n） have been synthesized and characterized by 1H NMR and ESI-MS spectroscopy. The effect...A series of heterogemini imidazolium surfactants with two-methylene spacer groups （[Cm- 2-Cnim]Br2, m, n=8, 10, 12, 14, 16; m≠n） have been synthesized and characterized by 1H NMR and ESI-MS spectroscopy. The effects of various reaction parameters, including stoichiometry, reaction temperature and time, were investigated. In addition, the surface activity study about heterogemini imidazolium surfactants was carried out and the influences of dissymmetric degree on the surface properties were also discussed.展开更多
A novel geminal imidazolium ionic liquid with long hydrocarbon group, 1,4-bis （3-tetradecylimidazolium- 1-yl） butane bromide was synthesized and an efficient synthesized method was introduced detailedly. Its structu...A novel geminal imidazolium ionic liquid with long hydrocarbon group, 1,4-bis （3-tetradecylimidazolium- 1-yl） butane bromide was synthesized and an efficient synthesized method was introduced detailedly. Its structure was determined by FT-IR, ^1H NMR and elemental analysis.展开更多
The application of ionic liquids in perovskite has attracted wide-spread attention for its astounding performance improvement of perovskite solar cells(PSCs).However,the detailed mechanisms behind the improvement rema...The application of ionic liquids in perovskite has attracted wide-spread attention for its astounding performance improvement of perovskite solar cells(PSCs).However,the detailed mechanisms behind the improvement remain mysterious.Herein,a series of imidazolium-based ionic liquids(IILs)with different cations and anions is systematically investigated to elucidate the passivation mechanism of IILs on inorganic perovskites.It is found that IILs display the following advantages:(1)They form ionic bonds with Cs^(+)and Pb^(2+)cations on the surface and at the grain boundaries of perovskite films,which could effectively heal/reduce the Cs^(+)/I−vacancies and Pb-related defects;(2)They serve as a bridge between the perovskite and the hole-transport-layer for effective charge extraction and transfer;and(3)They increase the hydrophobicity of the perovskite surface to further improve the stability of the CsPbI_(2)Br PSCs.The combination of the above effects results in suppressed non-radiative recombination loss in CsPbI_(2)Br PSCs and an impressive power conversion efficiency of 17.02%.Additionally,the CsPbI_(2)Br PSCs with IILs surface modification exhibited improved ambient and light illumination stability.Our results provide guidance for an indepth understanding of the passivation mechanism of IILs in inorganic perovskites.展开更多
Benzoin condensation promoted efficiently in three imidazolium based room tempera- ture ionic liquids [bmim]Br, [bmim]BF4 and [Bnmim]BF4 is reported for the first time. Benzoins were obtained in up to 91% yield within...Benzoin condensation promoted efficiently in three imidazolium based room tempera- ture ionic liquids [bmim]Br, [bmim]BF4 and [Bnmim]BF4 is reported for the first time. Benzoins were obtained in up to 91% yield within less than 30 min under mild conditions.展开更多
Development of high-performance hydroxide-conductive membranes is a focus research subject owing to promising applications in electrochemical reduction of CO_(2)(eCO_(2)RR).However,few satisfactory membranes have been...Development of high-performance hydroxide-conductive membranes is a focus research subject owing to promising applications in electrochemical reduction of CO_(2)(eCO_(2)RR).However,few satisfactory membranes have been developed to maximize the performance of CO_(2) electrolyzers,despite its role as the core in regulating ion transport and preventing product crossover or fuel loss.Herein,we report the synthesis of alkaline anion-exchange membranes fabricated by poly(vinyl-alcohol)(PVA)and poly[(3-methyl-1-vinylimidazoliummethylsulfate)-co-(1-vinylpyrrolidone)](PQ44)for use in CO_(2) electrolysis.Owing to the unique imidazolium ring structure coupled with a three-dimensional semiinterpenetrating porous internal architecture,the PVA/PQ44-OH-membranes provide a high hydroxide conductivity(21.47 mS cm^(-1)),preferable mechanical property and thermal stability.In particular,the eCO_(2)RR used PVA/PQ44-OH^(-) as electrolyte membrane realized a charming Faradaic efficiency(88%)and partial current density(29 mA cm^(-2))at0.96 VRHE and,delivered the excellent durability over 20 h electrolysis in 0.5 mol L^(-1) KHCO_(3) electrolyte.Notably,it can even enable an ultrahigh current density beyond 100 mA cm^(-2) at^(-1).11 VRHE when the electrolyte was KOH instead,and produced the FEHCOOof 85%at a low potential of0.81 VRHE,superior to both commercial alkaline A201 and acidic Nafion117 membrane.展开更多
{[Cu_3（cis-DAM）_4（OH）_2]·12H_2O}_n 1 and [Ag_3（trans-DAM）_2（NO_3）]_n 2 with a flexible ligand N,NA-diacetic acid imidazolium（HDAM） were synthesized and characterized by single-crystal X-ray diffraction....{[Cu_3（cis-DAM）_4（OH）_2]·12H_2O}_n 1 and [Ag_3（trans-DAM）_2（NO_3）]_n 2 with a flexible ligand N,NA-diacetic acid imidazolium（HDAM） were synthesized and characterized by single-crystal X-ray diffraction. Compound 1 crystallizes in the orthorhombic I222 space group with a = 12.033（2）,b = 12.498（3）,c = 14.963（3） A,V = 2250.4（8） A^3,Z = 8,C_7H_（13.5）N_2O_（7.5）Cu_（0.75）,M_r = 293.35,D_c = 1.732 g·cm^-3,F（000） = 1210,GOF = 1.087,the final R（I 〉 2σ（I）） = 0.0521 and w R（all data） = 0.1386. Compound 2 crystallizes in the monoclinic C2/c space group with a = 21.601（4）,b = 8.321（2）,c = 13.589（3） A,β = 126.95（3）°,V = 1951.9（7） A^3,Z = 8,C_7H_7N_（2.5）O_（5.5）Ag_（1.5）,M_r = 375.96,D_c = 2.559 g·cm^-3,F（000） = 1448,GOF = 1.017,R（I 〉 2σ（I）） = 0.0222 and w R（all data） = 0.0633. Compound 1 displays a novel 2D layer,consisting of a couple of left-helical chains with a pitch of 12.498（3） A formed by μ_3-cis-DAM~– ligands and Cu（1） ions,which are stabilized by hydrogen bonding interactions to give a 3D supramolecular framework. As for 2,Ag（1） ions are doubly bridged by trans-DAM~– and NO_3~– to form [Ag（1）_2O_4] chains,which are further connected by Ag（2） and trans-DAM~– to build a 3D framework. Additionally,thermogravimetric analyses,FT-IR spectroscopy,UV-visible spectroscopy,and the fluorescent properties were discussed.展开更多
In this study, two new co-crystals based on rigid imidazolium ligand （2,2＇-（（1,1’- biphenyl）-4,4＇-diyl）bis（2H-imidazo[1,5-a]pyridine-4-ium） hexafluorophosphate （L）） and 4,4＇- bipyridine （Bpy） and benze...In this study, two new co-crystals based on rigid imidazolium ligand （2,2＇-（（1,1’- biphenyl）-4,4＇-diyl）bis（2H-imidazo[1,5-a]pyridine-4-ium） hexafluorophosphate （L）） and 4,4＇- bipyridine （Bpy） and benzene （Ben）, formulated as L（Bpy）0.5 （co-crystal 1） and L（Ben） （co-crystal 2）, were obtained. Crystal data for 1： Pī space group with α = 10.921（4）, b = 16.998（6）, c = 17.666（6） A, α = 95.720（7）, β = 104.272（7）, γ = 93.340（6）°, V = 3150.5（19） A^3 and Z = 2; and crystal data for 2： monoclinic C2/m space group with α = 25.90（2）, b = 9.631（9）, c = 6.371（6） A, β = 95.26（2）°, V = 1583（2） A3 and Z = 2. Co-crystal 1 was dependent on hydrogen bonds and π···π stacking, while only hydrogen bonds are present in 2. Two new co-crystals were characterized by IR, NMR spectra, thermogravimetric and ultraviolet absorption analyses.展开更多
Novel dual-ionic imidazolium salts are shown to display excellent catalytic activity for cycloaddition of carbon dioxide and epoxides under room temperature and atmospheric pressure(0.1 MPa)without any solvent and co-...Novel dual-ionic imidazolium salts are shown to display excellent catalytic activity for cycloaddition of carbon dioxide and epoxides under room temperature and atmospheric pressure(0.1 MPa)without any solvent and co-catalyst leading to 96.1%product yield.It can be reused five times to keep the product yield over 90%.These intriguing results are attributed to a new reaction mechanism,which is supported by theoretical calculations along with the measurements of ^(13)C NMR spectrum and Fourier transform infrared spectroscopy(FT-IR).The excellent catalytic activity can be traced to a CO_(2)-philic group along with an electrophilic hydrogen atom.Our work shows that incorporation of CO_(2)-philic group is an feasible pathway to develop the new efficient ionic liquids.展开更多
The Hartree-Fock method has been employed to investigate the electronic structures of EMIM^＋（1-ethyl-3-methyl-imidazolium^＋）, CuCl2^-, Cu2Cl3^-, CuCl3^2-, EMIM＋^-CuCl2^-, EMIM^＋-Cu2Cl3^-, and EMIM^＋-CuCl3^2- pa...The Hartree-Fock method has been employed to investigate the electronic structures of EMIM^＋（1-ethyl-3-methyl-imidazolium^＋）, CuCl2^-, Cu2Cl3^-, CuCl3^2-, EMIM＋^-CuCl2^-, EMIM^＋-Cu2Cl3^-, and EMIM^＋-CuCl3^2- pairs. Full optimization and frequency analyses of EMIM^＋, CuCl2^-, Cu2Cl3^-, CuC13^-, eight initial EMIM^＋-CuCl2^-, six EMIM^＋-Cu2Cl3^-, and four EMIM^＋-CuCl3^2- geometries have been carried out using Gaussian-94 soft-package at 6-31＋G（d,p） basis set level for hydrogen, carbon, nitrogen, chlorine atoms and Hay-Wadt effective core potential for copper atom. The electronic structures of lowest energy of EMIM^＋-CuCl2^-, EMIM＋-Cu2Cl3^-, EMIM^＋-CuCl3^2-, single EMIM^＋, CuCl2^-, Cu2Cl3^-, and CuCl3^2- have been comparatively studied. The calculated results showed that EMIM^＋-CuCl2^- pair conformer of lowest energy was five ring parallel to Cl-Cu-Cl with 3.2A distance, EMIM^＋-CuCl3^2- pair conformer of lowest energy was five ring parallel to CuCl3^2-plane with 3.4A distance, and the optimized EMIM^＋-Cu2Cl3^- pair conformer of lowest energy was five ring perpendicular to Cl-Cu-Cl-Cu-Cl plane with 3.0A distance between the terminal Cl atoms and the 5-ring of EMIM^＋. The cohesion between cations and anions is brought about by C-H. C1 hydrogen bonds that are reinforced by charge assistance. The frequency analyses suggested that all stationary points are minimum because of no appearing of imaginary frequency. The assigned frequencies were in agreement with the experimental report. The low energy of interaction because of the bulkyasymmetry of EMIM＋ and the charge dispersion of cation and anion leads to the low melting point of the ionic liquids, EMIM^＋-CuCl2^-, EMIM^＋-Cu2Cl3^-, and EMIM^＋-CuCl3^2-. The interaction energy of EMIM^＋-CuCl2^-, EMIM^＋-Cu2Cl3^-, and EMIM^＋-CuCl3^2- is 309.0 kJ/mol, 316.8 kJ/mol, and 320.2 kJ/mol, respectively. The relationship of interaction energy via distance between cations and anions was also investigated by single point energy scan.展开更多
Two coordination compounds with a flexible ligand N,N？-diacetic acid imidazolium（HDAM）,{[Co（trans-DAM）（bipy）（H2O）2]（OH）·4H2O}n 1 and {[Cd（trans-DAM）（bipy）（H2O）]（NO3）？2H2O}n 2（bipy = 4,4＇-bip...Two coordination compounds with a flexible ligand N,N？-diacetic acid imidazolium（HDAM）,{[Co（trans-DAM）（bipy）（H2O）2]（OH）·4H2O}n 1 and {[Cd（trans-DAM）（bipy）（H2O）]（NO3）？2H2O}n 2（bipy = 4,4＇-bipyridine）,were prepared and characterized by single-crystal X-ray diffraction.Compound 1 crystallizes in monoclinic,space group P2/n with a = 7.589（6）,b = 11.444（2）,c = 12.894（3）（A°）,β = 90.99（3）°,V = 1119.8（4）（A°）^3,Z = 4,C8.5H14N2O5.5Co0.5,Mr = 261.68,Dc = 1.552 g/cm^3,F（000） = 546,μ = 0.832 mm^-1,the final R = 0.0657 and wR = 0.1958.Compound 2 crystallizes in the monoclinic C2 space group with a = 17.479（4）,b = 11.689（2）,c = 11.670（2）,β = 117.13（3）°,V = 2121.9（7）3,Z = 4,C17H21N5O10Cd,Mr = 567.79,Dc = 1.777 g/cm^3,F（000） = 1144,μ = 1.096 mm^-1,the final R = 0.0233 and wR = 0.0638.In 1,the Co（II） ions are linked by μ2-trans-DAM-and bipy ligands to build a 2D（4,4） rectangular grid layer,exhibiting a 4-connected sql net.As for 2,μ3-trans-DAM-and bipy bridge Cd（II） ions form a 2D double-layer,consisting of a couple of（4,4） grid layers,which can be viewed as a（3,4）-connected network.In both compounds,the 2D structures are stabilized by hydrogen bonding interactions to give 3D supramolecular frameworks.Additionally,FT-IR spectroscopy,UV-Visible spectroscopy,and the fluorescent properties are discussed.展开更多
A new compound {[Bi（trans-DAM）（cis-DAM）（H2O）]NO3·H2O}n 1 derived from bismuth and the flexible ligand N,N＇-diacetic acid imidazolium chloride （H2DAMCl） was obtained by hydrothermal synthesis and characte...A new compound {[Bi（trans-DAM）（cis-DAM）（H2O）]NO3·H2O}n 1 derived from bismuth and the flexible ligand N,N＇-diacetic acid imidazolium chloride （H2DAMCl） was obtained by hydrothermal synthesis and characterized by single-crystal X-ray diffraction. Compound 1 crystallizes in the monoclinic P21/c space group with a = 9.2298（18）, b = 13.339（3）, c = 17.090（3） , β = 105.38（2）°, V = 2028.7（7）A^3, Z = 4, C14H18N5O13Bi, Mr = 673.31, Dc = 2.204 g/cm^3, F（000） = 1296, μ = 8.772 mm-1, the final R = 0.0472 and wR = 0.1441 for 4129 observed reflections （I 〉 2σ（I））. In 1, the carboxylic groups from DAM- ligands adopt a cheating mode to link bismuth ions to form a 2D sheet network. These sheets are further connected by hydrogen bonding interactions to give an interesting 3D supramolecular framework. 2D correlation analysis of IR of 1 with thermal and magnetic perturbation was introduced to ascertain the characteristic adsorption of the groups overlapped in the 1D IR spectrum. Additionally, compound 1 exhibits fluorescent emission at room temperature.展开更多
To electrochemically extract Pb from PbO at room temperature, a new electrolyte, urea-1-ethyl-3-methylimidazolium fluoride(urea-[EMIM]F), was synthesized to dissolve PbO. Afterwards, the electrochemical behavior of Pb...To electrochemically extract Pb from PbO at room temperature, a new electrolyte, urea-1-ethyl-3-methylimidazolium fluoride(urea-[EMIM]F), was synthesized to dissolve PbO. Afterwards, the electrochemical behavior of Pb in this electrolyte was studied. The density, viscosity and conductivity of this electrolyte were investigated before electroextraction. The electrochemical behavior of Pb in the urea-[EMIM]F system was recorded via cyclic voltammograms, chronoamperometry and potentiostatic electrolysis. The results illustrate that Pb can be electrochemically extracted from PbO in this system at room temperature and that Pb reduction involves a quasireversible process and follows a one-step and two-electron transfer process. The reduction of Pb proceeds with a three-dimensional(3 D) progressive model. With an increase in temperature, the onset potentials for Pb reduction shift anodically. The diffusion coefficient of Pb(II) is determined to be 6.88×10-10 cm2/s at 353 K. Additionally, spherical Pb particles are obtained after electrodeposition in the urea-[EMIM]F system via potentiostatic electrolysis.展开更多
Two imidazolium bis-estrogens as a new type of biomimetic model, which possesspotential multiple biomimetic functions, were srnthesized in gcod yields by three steps fromestrogen. All new compounds were characterized ...Two imidazolium bis-estrogens as a new type of biomimetic model, which possesspotential multiple biomimetic functions, were srnthesized in gcod yields by three steps fromestrogen. All new compounds were characterized by MS, 1HNMR and elemental analysis.展开更多
The geometries of reactant, product and transition state of the title reaction have been optimized by using density functional theory (DFT) at the B3LYP/6-31G(d,p) and B3LYP/6- 311++G(d,p) levels. The variations of th...The geometries of reactant, product and transition state of the title reaction have been optimized by using density functional theory (DFT) at the B3LYP/6-31G(d,p) and B3LYP/6- 311++G(d,p) levels. The variations of the bond parameters in the course of reaction were analyzed. The zero point energy corrections were performed by vibrational analysis. The equilibrium states and the transition state were verified according to the number of virtue frequency of geometry. The intrinsic reaction coordinates (IRC) were calculated from the transition state. The calculated results show that the double bond rearrangement of butene catalyzed by 1-butyl-3-methyl-imidazolium cation is a one-step reaction. The forward energy barrier of isomerization from 1-butene to 2- butene is about 193 kJ·mol-1 and the reverse energy barrier about 209 kJ·mol-1 at the B3LYP/6- 31G(d,p) level, which means that the reaction is easy to proceed at or above room temperature.展开更多
The antibacterial polyamide 6(PA6)material has attracted great research interest due to its wide ap-plication in food packaging,biomedical fields,functional textiles,and other fields.However,it is still a challenge to...The antibacterial polyamide 6(PA6)material has attracted great research interest due to its wide ap-plication in food packaging,biomedical fields,functional textiles,and other fields.However,it is still a challenge to prepare intrinsically antibacterial PA6 with highly efficient and durably antibacterial activity via polymerization.Herein,the antibacterial imidazolium ionic liquid of 3-carboxymethyl-1-decyl imida-zole chloride was designed and synthesized for adapting the polymerization and processing temperature of PA6.Then antibacterial PA6(PA6-IL)was synthesized through hydrolyzed ring-opening copolymeriza-tion with imidazolium at the end of the backbones.Compared to physical blending or post-modification methods,antibacterial agents as end-capping reagents of polymer backbones endowed PA6 with intrin-sic antibacterial activity.As expected,the obtained PA6-IL exhibited not just comparable physicochemical and mechanical properties to conventional PA6 but excellent antibacterial activity of low antibacterial time to 60 min and durability for 28 days.Additionally,the corresponding electrospun PA6-IL nanofi-brous membranes showed homogenous morphology and remarkable hydrophilicity of 7.7° as well as the high-efficient antibacterial activity.Melt-spun PA6-IL microfibers revealed a smooth surface as well as enhanced tensile strength and increased breaking elongation compared to those of conventional PA6.The PA6-IL microfibers also behaved with excellent antibacterial efficiency and durability.Accordingly,this work provides a feasible and straightforward strategy to prepare durably and intrinsically antibacterial PA6 materials especially PA6 fibers,which can be widely applied in the textiles field.展开更多
In this study, 1,3-disulfonic acid imidazolium hydrogen sulfate （DSIMHS） is used as an efficient and reusable ionic liquid for the green, mild, and efficient synthesis of xanthenes under solvent-free conditions. Sim...In this study, 1,3-disulfonic acid imidazolium hydrogen sulfate （DSIMHS） is used as an efficient and reusable ionic liquid for the green, mild, and efficient synthesis of xanthenes under solvent-free conditions. Simple and easy work-up, low cost, green process, short reaction times and excellent yields of the products are the advantages of this procedure. Further, the catalyst can be recycled and reused at least for four times without a noticeably decrease in its catalytic activity.展开更多
Heteroatom-doped carbon materials as alternative catalysts for oxygen reduction reaction(ORR)have drawn increasing attention due to their tunable chemical and electronic structures for achieving high activity and stab...Heteroatom-doped carbon materials as alternative catalysts for oxygen reduction reaction(ORR)have drawn increasing attention due to their tunable chemical and electronic structures for achieving high activity and stability. However, there still remains a great challenge to fabricate porous heteroatoms dual-doped carbons with uniformly doping in a facile and controllable way. Herein,imidazole/imidazolium-functionalized metal-organic frameworks(MOFs) are employed as precursors and templates to achieve porous nitrogen and halogen dual-doped nanocarbons. Among these carbon materials, the as-prepared nitrogen/bromine dual-doped catalyst BrNC-800 exhibits the best ORR performance with a positive half-wave potential at 0.80 V(vs. RHE) in 0.1 mol L-1 KOH, which is comparable to the benchmark commercial 20 wt% Pt/C catalyst. BrNC-800 shows excellent long term stability and methanol tolerance.This work provides a facile approach to fabricate highly efficient heteroatoms dual-doped carbon catalysts for energy conversion.展开更多
The relative chemical shifts (△δ) △δwere put forward to investigate the microscopic structure of 1-ethyl-3-methyl-imidazolium tetrafluoroborate (EmimBF4) during the dilution process with water.The concentration-de...The relative chemical shifts (△δ) △δwere put forward to investigate the microscopic structure of 1-ethyl-3-methyl-imidazolium tetrafluoroborate (EmimBF4) during the dilution process with water.The concentration-dependent △δ(C2)H-(C4)H,△δ(C2)H-(C5)H and △δ(C4)H-(C5)H were analyzed.The results reveal that the variations of the microscopic structures of three aromatic protons are inconsistent.The strength of the H-bond between water and three aromatic protons follows the order:(C2)H···O 】 (C4)H···O 】 (C5)H···O.The concentration-dependent △δ(C6)H-(C7)H and △δ(C6)H-(C8)H indicate the formation of the H-bonds of (Calkyl)H···O is impossible,and more water is located around (C6)H than around (C7)H or (C8)H.The concentration-dependent △δ(C2)H-(C4)H and △δ(C2)H-(C5)H both increase rapidly when xwater 】 0.9 or so,suggesting the ionic pairs of EmimBF4 are dissociated rapidly.The turning points of concentration-dependent △δ(C2)H-(C4)H and △δ(C2)H-(C5)H indicate that some physical properties of the EmimBF4/water mixtures also change at the corresponding concentration point.The microscopic structures of EmimBF4 in water could be clearly detected by the relative chemical shifts.展开更多
Imidazolium-based elastomeric ionomers （i-BIIR） were facilely synthesized by ionically modified brominated poly（isobutylene-co-isoprene） （BIIR） with different alkyl chain imidazole and thoroughly explored as nov...Imidazolium-based elastomeric ionomers （i-BIIR） were facilely synthesized by ionically modified brominated poly（isobutylene-co-isoprene） （BIIR） with different alkyl chain imidazole and thoroughly explored as novel toughening agents for poly（lactic acid） （PLA）. The miscibility, thermal behavior, phase morphology and mechanical property of ionomers and blends were investigated through dynamic mechanical analyses （DMA）, differential scanning calorimetry （DSC）, scanning electron microscopy （SEM）, tensile and impact testing. DMA and SEM results showed that better compatibility between the PLA and i-BIIR was achieved compared to the PLA/unmodified BIIR elastomer. A remarkable improvement in ductility with an optimum elongation at break up to 235% was achieved for the PLA/i-BIIR blends with 1-dodecylimidazole alkyl chain （i-BIIR-12）, more than 10 times higher than that of pure PLA. The impact strengths of PLA were enhanced from 1.9 kJ/m2 to 4.1 k J/m2 for the PLA/10 wt% i-BIIR-12 blend. Toughening mechanism had been established by systematical analysis of the compatibility, intermolecular interaction and phase structures of the blends. Interracial cavitations initiated massive shear yielding of the PLA matrix owing to a suitable interfacial adhesion which played a key role in the enormous toughening effect in these blends. We believed that introducing imidazolium group into the BIIR elastomer was vital for the formation of a suitable interfacial adhesion.展开更多
文摘A series of heterogemini imidazolium surfactants with two-methylene spacer groups （[Cm- 2-Cnim]Br2, m, n=8, 10, 12, 14, 16; m≠n） have been synthesized and characterized by 1H NMR and ESI-MS spectroscopy. The effects of various reaction parameters, including stoichiometry, reaction temperature and time, were investigated. In addition, the surface activity study about heterogemini imidazolium surfactants was carried out and the influences of dissymmetric degree on the surface properties were also discussed.
文摘A novel geminal imidazolium ionic liquid with long hydrocarbon group, 1,4-bis （3-tetradecylimidazolium- 1-yl） butane bromide was synthesized and an efficient synthesized method was introduced detailedly. Its structure was determined by FT-IR, ^1H NMR and elemental analysis.
基金support from the National Natural Science Foundation of China(62074095)the National Key Research and Development Program of China(2016YFA0202403)+3 种基金the Fundamental Research Funds for the Central Universities(GK202002001)the 111 Project(Grant No.B21005)the DNL Cooperation Fund CAS(DNL180311)the support of H2 cluster in Xi’an Jiaotong University.
文摘The application of ionic liquids in perovskite has attracted wide-spread attention for its astounding performance improvement of perovskite solar cells(PSCs).However,the detailed mechanisms behind the improvement remain mysterious.Herein,a series of imidazolium-based ionic liquids(IILs)with different cations and anions is systematically investigated to elucidate the passivation mechanism of IILs on inorganic perovskites.It is found that IILs display the following advantages:(1)They form ionic bonds with Cs^(+)and Pb^(2+)cations on the surface and at the grain boundaries of perovskite films,which could effectively heal/reduce the Cs^(+)/I−vacancies and Pb-related defects;(2)They serve as a bridge between the perovskite and the hole-transport-layer for effective charge extraction and transfer;and(3)They increase the hydrophobicity of the perovskite surface to further improve the stability of the CsPbI_(2)Br PSCs.The combination of the above effects results in suppressed non-radiative recombination loss in CsPbI_(2)Br PSCs and an impressive power conversion efficiency of 17.02%.Additionally,the CsPbI_(2)Br PSCs with IILs surface modification exhibited improved ambient and light illumination stability.Our results provide guidance for an indepth understanding of the passivation mechanism of IILs in inorganic perovskites.
基金We thank the financial support from the National Natural Science Foundation of China.(No.20172038)
文摘Benzoin condensation promoted efficiently in three imidazolium based room tempera- ture ionic liquids [bmim]Br, [bmim]BF4 and [Bnmim]BF4 is reported for the first time. Benzoins were obtained in up to 91% yield within less than 30 min under mild conditions.
基金support from the“Scientific and Technical Innovation Action Plan”Basic Research Field of Shanghai Science and Technology Committee (19JC1410500)the National Natural Science Foundation of China (21972017).
文摘Development of high-performance hydroxide-conductive membranes is a focus research subject owing to promising applications in electrochemical reduction of CO_(2)(eCO_(2)RR).However,few satisfactory membranes have been developed to maximize the performance of CO_(2) electrolyzers,despite its role as the core in regulating ion transport and preventing product crossover or fuel loss.Herein,we report the synthesis of alkaline anion-exchange membranes fabricated by poly(vinyl-alcohol)(PVA)and poly[(3-methyl-1-vinylimidazoliummethylsulfate)-co-(1-vinylpyrrolidone)](PQ44)for use in CO_(2) electrolysis.Owing to the unique imidazolium ring structure coupled with a three-dimensional semiinterpenetrating porous internal architecture,the PVA/PQ44-OH-membranes provide a high hydroxide conductivity(21.47 mS cm^(-1)),preferable mechanical property and thermal stability.In particular,the eCO_(2)RR used PVA/PQ44-OH^(-) as electrolyte membrane realized a charming Faradaic efficiency(88%)and partial current density(29 mA cm^(-2))at0.96 VRHE and,delivered the excellent durability over 20 h electrolysis in 0.5 mol L^(-1) KHCO_(3) electrolyte.Notably,it can even enable an ultrahigh current density beyond 100 mA cm^(-2) at^(-1).11 VRHE when the electrolyte was KOH instead,and produced the FEHCOOof 85%at a low potential of0.81 VRHE,superior to both commercial alkaline A201 and acidic Nafion117 membrane.
基金supported by Scientific and Technological Innovation Programs of Higher Education Institutions in Shanxi(No.2013152)the Doctoral Scientific Research Foundation of Yuncheng University(No.YQ-2014019)
文摘{[Cu_3（cis-DAM）_4（OH）_2]·12H_2O}_n 1 and [Ag_3（trans-DAM）_2（NO_3）]_n 2 with a flexible ligand N,NA-diacetic acid imidazolium（HDAM） were synthesized and characterized by single-crystal X-ray diffraction. Compound 1 crystallizes in the orthorhombic I222 space group with a = 12.033（2）,b = 12.498（3）,c = 14.963（3） A,V = 2250.4（8） A^3,Z = 8,C_7H_（13.5）N_2O_（7.5）Cu_（0.75）,M_r = 293.35,D_c = 1.732 g·cm^-3,F（000） = 1210,GOF = 1.087,the final R（I 〉 2σ（I）） = 0.0521 and w R（all data） = 0.1386. Compound 2 crystallizes in the monoclinic C2/c space group with a = 21.601（4）,b = 8.321（2）,c = 13.589（3） A,β = 126.95（3）°,V = 1951.9（7） A^3,Z = 8,C_7H_7N_（2.5）O_（5.5）Ag_（1.5）,M_r = 375.96,D_c = 2.559 g·cm^-3,F（000） = 1448,GOF = 1.017,R（I 〉 2σ（I）） = 0.0222 and w R（all data） = 0.0633. Compound 1 displays a novel 2D layer,consisting of a couple of left-helical chains with a pitch of 12.498（3） A formed by μ_3-cis-DAM~– ligands and Cu（1） ions,which are stabilized by hydrogen bonding interactions to give a 3D supramolecular framework. As for 2,Ag（1） ions are doubly bridged by trans-DAM~– and NO_3~– to form [Ag（1）_2O_4] chains,which are further connected by Ag（2） and trans-DAM~– to build a 3D framework. Additionally,thermogravimetric analyses,FT-IR spectroscopy,UV-visible spectroscopy,and the fluorescent properties were discussed.
基金supported by the National Natural Science Foundation of China(21102117)the Education Department of Sichuan Province(09ZX010)the College Student Science and Technology Innovation Key Foundation of China West Normal University(42712074)
文摘In this study, two new co-crystals based on rigid imidazolium ligand （2,2＇-（（1,1’- biphenyl）-4,4＇-diyl）bis（2H-imidazo[1,5-a]pyridine-4-ium） hexafluorophosphate （L）） and 4,4＇- bipyridine （Bpy） and benzene （Ben）, formulated as L（Bpy）0.5 （co-crystal 1） and L（Ben） （co-crystal 2）, were obtained. Crystal data for 1： Pī space group with α = 10.921（4）, b = 16.998（6）, c = 17.666（6） A, α = 95.720（7）, β = 104.272（7）, γ = 93.340（6）°, V = 3150.5（19） A^3 and Z = 2; and crystal data for 2： monoclinic C2/m space group with α = 25.90（2）, b = 9.631（9）, c = 6.371（6） A, β = 95.26（2）°, V = 1583（2） A3 and Z = 2. Co-crystal 1 was dependent on hydrogen bonds and π···π stacking, while only hydrogen bonds are present in 2. Two new co-crystals were characterized by IR, NMR spectra, thermogravimetric and ultraviolet absorption analyses.
基金supported by the National Natural Science Foundation of China(21975064)Program of Henan Center for Outstanding Overseas Scientists(GZS2020011)+1 种基金Henan University's first-class discipline science and technology research project(2018YLTD07,2018YLZDYJ11,2019YLZDYJ09)the Excellent Foreign Experts Project of Henan University。
文摘Novel dual-ionic imidazolium salts are shown to display excellent catalytic activity for cycloaddition of carbon dioxide and epoxides under room temperature and atmospheric pressure(0.1 MPa)without any solvent and co-catalyst leading to 96.1%product yield.It can be reused five times to keep the product yield over 90%.These intriguing results are attributed to a new reaction mechanism,which is supported by theoretical calculations along with the measurements of ^(13)C NMR spectrum and Fourier transform infrared spectroscopy(FT-IR).The excellent catalytic activity can be traced to a CO_(2)-philic group along with an electrophilic hydrogen atom.Our work shows that incorporation of CO_(2)-philic group is an feasible pathway to develop the new efficient ionic liquids.
文摘The Hartree-Fock method has been employed to investigate the electronic structures of EMIM^＋（1-ethyl-3-methyl-imidazolium^＋）, CuCl2^-, Cu2Cl3^-, CuCl3^2-, EMIM＋^-CuCl2^-, EMIM^＋-Cu2Cl3^-, and EMIM^＋-CuCl3^2- pairs. Full optimization and frequency analyses of EMIM^＋, CuCl2^-, Cu2Cl3^-, CuC13^-, eight initial EMIM^＋-CuCl2^-, six EMIM^＋-Cu2Cl3^-, and four EMIM^＋-CuCl3^2- geometries have been carried out using Gaussian-94 soft-package at 6-31＋G（d,p） basis set level for hydrogen, carbon, nitrogen, chlorine atoms and Hay-Wadt effective core potential for copper atom. The electronic structures of lowest energy of EMIM^＋-CuCl2^-, EMIM＋-Cu2Cl3^-, EMIM^＋-CuCl3^2-, single EMIM^＋, CuCl2^-, Cu2Cl3^-, and CuCl3^2- have been comparatively studied. The calculated results showed that EMIM^＋-CuCl2^- pair conformer of lowest energy was five ring parallel to Cl-Cu-Cl with 3.2A distance, EMIM^＋-CuCl3^2- pair conformer of lowest energy was five ring parallel to CuCl3^2-plane with 3.4A distance, and the optimized EMIM^＋-Cu2Cl3^- pair conformer of lowest energy was five ring perpendicular to Cl-Cu-Cl-Cu-Cl plane with 3.0A distance between the terminal Cl atoms and the 5-ring of EMIM^＋. The cohesion between cations and anions is brought about by C-H. C1 hydrogen bonds that are reinforced by charge assistance. The frequency analyses suggested that all stationary points are minimum because of no appearing of imaginary frequency. The assigned frequencies were in agreement with the experimental report. The low energy of interaction because of the bulkyasymmetry of EMIM＋ and the charge dispersion of cation and anion leads to the low melting point of the ionic liquids, EMIM^＋-CuCl2^-, EMIM^＋-Cu2Cl3^-, and EMIM^＋-CuCl3^2-. The interaction energy of EMIM^＋-CuCl2^-, EMIM^＋-Cu2Cl3^-, and EMIM^＋-CuCl3^2- is 309.0 kJ/mol, 316.8 kJ/mol, and 320.2 kJ/mol, respectively. The relationship of interaction energy via distance between cations and anions was also investigated by single point energy scan.
基金supported by the National Natural Science Foundation of China (No. 20873021)
文摘Two coordination compounds with a flexible ligand N,N？-diacetic acid imidazolium（HDAM）,{[Co（trans-DAM）（bipy）（H2O）2]（OH）·4H2O}n 1 and {[Cd（trans-DAM）（bipy）（H2O）]（NO3）？2H2O}n 2（bipy = 4,4＇-bipyridine）,were prepared and characterized by single-crystal X-ray diffraction.Compound 1 crystallizes in monoclinic,space group P2/n with a = 7.589（6）,b = 11.444（2）,c = 12.894（3）（A°）,β = 90.99（3）°,V = 1119.8（4）（A°）^3,Z = 4,C8.5H14N2O5.5Co0.5,Mr = 261.68,Dc = 1.552 g/cm^3,F（000） = 546,μ = 0.832 mm^-1,the final R = 0.0657 and wR = 0.1958.Compound 2 crystallizes in the monoclinic C2 space group with a = 17.479（4）,b = 11.689（2）,c = 11.670（2）,β = 117.13（3）°,V = 2121.9（7）3,Z = 4,C17H21N5O10Cd,Mr = 567.79,Dc = 1.777 g/cm^3,F（000） = 1144,μ = 1.096 mm^-1,the final R = 0.0233 and wR = 0.0638.In 1,the Co（II） ions are linked by μ2-trans-DAM-and bipy ligands to build a 2D（4,4） rectangular grid layer,exhibiting a 4-connected sql net.As for 2,μ3-trans-DAM-and bipy bridge Cd（II） ions form a 2D double-layer,consisting of a couple of（4,4） grid layers,which can be viewed as a（3,4）-connected network.In both compounds,the 2D structures are stabilized by hydrogen bonding interactions to give 3D supramolecular frameworks.Additionally,FT-IR spectroscopy,UV-Visible spectroscopy,and the fluorescent properties are discussed.
基金supported by the National Natural Science Foundation of China (No. 20873021)the State Key Laboratory of Structure Chemistry and the Young Talent Programmed of Fujian Province (No. 2006F3072)
文摘A new compound {[Bi（trans-DAM）（cis-DAM）（H2O）]NO3·H2O}n 1 derived from bismuth and the flexible ligand N,N＇-diacetic acid imidazolium chloride （H2DAMCl） was obtained by hydrothermal synthesis and characterized by single-crystal X-ray diffraction. Compound 1 crystallizes in the monoclinic P21/c space group with a = 9.2298（18）, b = 13.339（3）, c = 17.090（3） , β = 105.38（2）°, V = 2028.7（7）A^3, Z = 4, C14H18N5O13Bi, Mr = 673.31, Dc = 2.204 g/cm^3, F（000） = 1296, μ = 8.772 mm-1, the final R = 0.0472 and wR = 0.1441 for 4129 observed reflections （I 〉 2σ（I））. In 1, the carboxylic groups from DAM- ligands adopt a cheating mode to link bismuth ions to form a 2D sheet network. These sheets are further connected by hydrogen bonding interactions to give an interesting 3D supramolecular framework. 2D correlation analysis of IR of 1 with thermal and magnetic perturbation was introduced to ascertain the characteristic adsorption of the groups overlapped in the 1D IR spectrum. Additionally, compound 1 exhibits fluorescent emission at room temperature.
基金financial supports from the National Natural Science Foundation of China (51804070,52074084)Fundamental Research Funds for the Central Universities of China (N172502003)。
文摘To electrochemically extract Pb from PbO at room temperature, a new electrolyte, urea-1-ethyl-3-methylimidazolium fluoride(urea-[EMIM]F), was synthesized to dissolve PbO. Afterwards, the electrochemical behavior of Pb in this electrolyte was studied. The density, viscosity and conductivity of this electrolyte were investigated before electroextraction. The electrochemical behavior of Pb in the urea-[EMIM]F system was recorded via cyclic voltammograms, chronoamperometry and potentiostatic electrolysis. The results illustrate that Pb can be electrochemically extracted from PbO in this system at room temperature and that Pb reduction involves a quasireversible process and follows a one-step and two-electron transfer process. The reduction of Pb proceeds with a three-dimensional(3 D) progressive model. With an increase in temperature, the onset potentials for Pb reduction shift anodically. The diffusion coefficient of Pb(II) is determined to be 6.88×10-10 cm2/s at 353 K. Additionally, spherical Pb particles are obtained after electrodeposition in the urea-[EMIM]F system via potentiostatic electrolysis.
文摘Two imidazolium bis-estrogens as a new type of biomimetic model, which possesspotential multiple biomimetic functions, were srnthesized in gcod yields by three steps fromestrogen. All new compounds were characterized by MS, 1HNMR and elemental analysis.
基金This work was supported by the National Natural Science Key Foundation of China (20490209) and Young Teacher Foundation of Beijing Chemical Technology University (QN0308)
文摘The geometries of reactant, product and transition state of the title reaction have been optimized by using density functional theory (DFT) at the B3LYP/6-31G(d,p) and B3LYP/6- 311++G(d,p) levels. The variations of the bond parameters in the course of reaction were analyzed. The zero point energy corrections were performed by vibrational analysis. The equilibrium states and the transition state were verified according to the number of virtue frequency of geometry. The intrinsic reaction coordinates (IRC) were calculated from the transition state. The calculated results show that the double bond rearrangement of butene catalyzed by 1-butyl-3-methyl-imidazolium cation is a one-step reaction. The forward energy barrier of isomerization from 1-butene to 2- butene is about 193 kJ·mol-1 and the reverse energy barrier about 209 kJ·mol-1 at the B3LYP/6- 31G(d,p) level, which means that the reaction is easy to proceed at or above room temperature.
基金National Natural Science Foundation of China(Grant No.52273060)Science and Technology Research Project of the Educational Commission of Hubei Province(Grant No.D20221703)provide financial support.
文摘The antibacterial polyamide 6(PA6)material has attracted great research interest due to its wide ap-plication in food packaging,biomedical fields,functional textiles,and other fields.However,it is still a challenge to prepare intrinsically antibacterial PA6 with highly efficient and durably antibacterial activity via polymerization.Herein,the antibacterial imidazolium ionic liquid of 3-carboxymethyl-1-decyl imida-zole chloride was designed and synthesized for adapting the polymerization and processing temperature of PA6.Then antibacterial PA6(PA6-IL)was synthesized through hydrolyzed ring-opening copolymeriza-tion with imidazolium at the end of the backbones.Compared to physical blending or post-modification methods,antibacterial agents as end-capping reagents of polymer backbones endowed PA6 with intrin-sic antibacterial activity.As expected,the obtained PA6-IL exhibited not just comparable physicochemical and mechanical properties to conventional PA6 but excellent antibacterial activity of low antibacterial time to 60 min and durability for 28 days.Additionally,the corresponding electrospun PA6-IL nanofi-brous membranes showed homogenous morphology and remarkable hydrophilicity of 7.7° as well as the high-efficient antibacterial activity.Melt-spun PA6-IL microfibers revealed a smooth surface as well as enhanced tensile strength and increased breaking elongation compared to those of conventional PA6.The PA6-IL microfibers also behaved with excellent antibacterial efficiency and durability.Accordingly,this work provides a feasible and straightforward strategy to prepare durably and intrinsically antibacterial PA6 materials especially PA6 fibers,which can be widely applied in the textiles field.
基金the University of Guilan Research Council for the partial support
文摘In this study, 1,3-disulfonic acid imidazolium hydrogen sulfate （DSIMHS） is used as an efficient and reusable ionic liquid for the green, mild, and efficient synthesis of xanthenes under solvent-free conditions. Simple and easy work-up, low cost, green process, short reaction times and excellent yields of the products are the advantages of this procedure. Further, the catalyst can be recycled and reused at least for four times without a noticeably decrease in its catalytic activity.
基金the financial support from the National Key Research and Development Program of China (2018YFA0208600)National Basic Research Program of China (973 Program, 2014CB845605)+3 种基金Key Research Program of Frontier Science, Chinese Academy of Sciences (QYZDJ-SSW-SLH045)Strategic Priority Research Program of the Chinese Academy of Sciences (XDB20000000)National Natural Science Foundation of China (21671188, 21871263, 21521061 and 21331006)Youth Innovation Promotion Association,Chinese Academy of Sciences (2014265)
文摘Heteroatom-doped carbon materials as alternative catalysts for oxygen reduction reaction(ORR)have drawn increasing attention due to their tunable chemical and electronic structures for achieving high activity and stability. However, there still remains a great challenge to fabricate porous heteroatoms dual-doped carbons with uniformly doping in a facile and controllable way. Herein,imidazole/imidazolium-functionalized metal-organic frameworks(MOFs) are employed as precursors and templates to achieve porous nitrogen and halogen dual-doped nanocarbons. Among these carbon materials, the as-prepared nitrogen/bromine dual-doped catalyst BrNC-800 exhibits the best ORR performance with a positive half-wave potential at 0.80 V(vs. RHE) in 0.1 mol L-1 KOH, which is comparable to the benchmark commercial 20 wt% Pt/C catalyst. BrNC-800 shows excellent long term stability and methanol tolerance.This work provides a facile approach to fabricate highly efficient heteroatoms dual-doped carbon catalysts for energy conversion.
基金the National Natural Science Foundation of China (20773109 & 20704035)the Natural Science Foundation of Zhejiang Province (Y4090453)
文摘The relative chemical shifts (△δ) △δwere put forward to investigate the microscopic structure of 1-ethyl-3-methyl-imidazolium tetrafluoroborate (EmimBF4) during the dilution process with water.The concentration-dependent △δ(C2)H-(C4)H,△δ(C2)H-(C5)H and △δ(C4)H-(C5)H were analyzed.The results reveal that the variations of the microscopic structures of three aromatic protons are inconsistent.The strength of the H-bond between water and three aromatic protons follows the order:(C2)H···O 】 (C4)H···O 】 (C5)H···O.The concentration-dependent △δ(C6)H-(C7)H and △δ(C6)H-(C8)H indicate the formation of the H-bonds of (Calkyl)H···O is impossible,and more water is located around (C6)H than around (C7)H or (C8)H.The concentration-dependent △δ(C2)H-(C4)H and △δ(C2)H-(C5)H both increase rapidly when xwater 】 0.9 or so,suggesting the ionic pairs of EmimBF4 are dissociated rapidly.The turning points of concentration-dependent △δ(C2)H-(C4)H and △δ(C2)H-(C5)H indicate that some physical properties of the EmimBF4/water mixtures also change at the corresponding concentration point.The microscopic structures of EmimBF4 in water could be clearly detected by the relative chemical shifts.
基金financially support by the National Natural Science Foundation of China (No. 51573130)
文摘Imidazolium-based elastomeric ionomers （i-BIIR） were facilely synthesized by ionically modified brominated poly（isobutylene-co-isoprene） （BIIR） with different alkyl chain imidazole and thoroughly explored as novel toughening agents for poly（lactic acid） （PLA）. The miscibility, thermal behavior, phase morphology and mechanical property of ionomers and blends were investigated through dynamic mechanical analyses （DMA）, differential scanning calorimetry （DSC）, scanning electron microscopy （SEM）, tensile and impact testing. DMA and SEM results showed that better compatibility between the PLA and i-BIIR was achieved compared to the PLA/unmodified BIIR elastomer. A remarkable improvement in ductility with an optimum elongation at break up to 235% was achieved for the PLA/i-BIIR blends with 1-dodecylimidazole alkyl chain （i-BIIR-12）, more than 10 times higher than that of pure PLA. The impact strengths of PLA were enhanced from 1.9 kJ/m2 to 4.1 k J/m2 for the PLA/10 wt% i-BIIR-12 blend. Toughening mechanism had been established by systematical analysis of the compatibility, intermolecular interaction and phase structures of the blends. Interracial cavitations initiated massive shear yielding of the PLA matrix owing to a suitable interfacial adhesion which played a key role in the enormous toughening effect in these blends. We believed that introducing imidazolium group into the BIIR elastomer was vital for the formation of a suitable interfacial adhesion.
