A novel ionic compound [Fe（CN）6（phCH2NC5H5）3]·（H2O）4（Mr = 794.71） has been synthesized and its structure was characterized by IR, elemental analysis and X-my diffraction. The compound crystallizes in mono...A novel ionic compound [Fe（CN）6（phCH2NC5H5）3]·（H2O）4（Mr = 794.71） has been synthesized and its structure was characterized by IR, elemental analysis and X-my diffraction. The compound crystallizes in monoclinic, space group P21/c with a = 10.837（2）, b = 16.551（3）, c = 23.402（5） A, p = 97.531（4）°, V = 4161.0（15） A3, Z = 4, Dc = 1.269 g/cm^3, F（000） = 1668, p = 0.414 mm^-1, R = 0.0479 and wR = 0.1232. The building unit of the title compound consists of three （phCH2N＋C5H5） ions, one [Fe（CN）6]^3- anion and four water molecules. According to the structural analysis, UFe（CN）6]^3- are linked together by O-H…N and O-H…O hydrogen bonds, but UFe（CN）6]^3- and [ （phCH2N＋ C5H5）3] ions are bound by electrostatic force to form an ionic compound.展开更多
Inorganic hole transport materials, particularly NiO_X, have shown considerable promise in boosting the efficiency and stability of perovskite solar cells. However, a major barrier to commercialization of NiO_X-based ...Inorganic hole transport materials, particularly NiO_X, have shown considerable promise in boosting the efficiency and stability of perovskite solar cells. However, a major barrier to commercialization of NiO_X-based perovskite solar cells with positive-intrinsic-negative architectures is their direct contact with the absorbing layer, which can lead to losses of photovoltage and fill factor. Furthermore, highly positive under-coordinated Ni cations degrade the perovskite at the interface. Here, we address these issues with the use of an ionic compound(QAPyBF_(4)) as an additive to passivate defects throughout the perovskite layer and improve carrier conduction and interactions with under-coordinated Ni cations. Specifically,the highly electronegative inorganic anion [BF_(4)]~- interacts with the NiO_x/perovskite interface to passivate under-coordinated cations(Ni^(≥3+)). Accordingly, the decorated cells achieved a power conversion efficiency of 23.38% and a fill factor of 85.5% without a complex surface treatment or NiO_X doping.展开更多
A novel ionic compound [Fe（CN）6·（PhCHeNC9H7）4]·12H2O（C70H80FeN10O12, Mr = 1309.29） has been synthesized and its structure was characterized by I-R, elemental analysis and X-ray diffraction. The compoun...A novel ionic compound [Fe（CN）6·（PhCHeNC9H7）4]·12H2O（C70H80FeN10O12, Mr = 1309.29） has been synthesized and its structure was characterized by I-R, elemental analysis and X-ray diffraction. The compound crystaUizes in triclinic, space group P1, with a = 10.968（7）, b = 11.466（7）, c = 14.077（8）A, α= 87.014（7）, β= 78.124（7）, γ = 72.708（7）°, V = 1654.1（17）A3, Z = 1, Dc = 1.314 g·cm^-3, F（000） = 692, p = 0.298 mm^-1, the final R = 0.0519 and wR = 0.1355. The building unit of the title compound consists of four （PhCH2N＋C9H7） ions, one [Fe（CN）6]4- anion, and a dozen water molecules. According to the structural analysis, [Fe（CN）6]4- ions are linked together by O-H…O and O-H…N hydrogen bonds, while （PhCH2N＋C9HT） and [Fe（CN）6]4- ions interact with each other by electrostatic force to form an ionic compound.展开更多
Switchable ionic compounds have wide applications in chemical processes.A switchable ionic compound based on 1,8-diazabicyclo-[5.4.0]-undec-7-ene(DBU),CH_3OH and CO_2 was synthesized and characterized.DBU/CH_3OH/CO_2 ...Switchable ionic compounds have wide applications in chemical processes.A switchable ionic compound based on 1,8-diazabicyclo-[5.4.0]-undec-7-ene(DBU),CH_3OH and CO_2 was synthesized and characterized.DBU/CH_3OH/CO_2 ionic compound was prepared in the presence of excess methanol,and then the excess methanol was removed by reduced pressure distillation in CO_2 atmosphere.The product yield(100%) reached the theoretical maximum for the first time.Its structure was identified by NMR,FT-IR,and XRD.The crystal product shows 8strong peaks in XRD at 2θ values of 16.0547°,16.4308°,16.7651°,18.8714°,19.2140°,21.9471°,22.0780°,and25.5661°.Its decomposition onset temperature(53 ℃) was affirmed by TGA,which is lower than its melting point.And its ionic switch point was measured by conductivity.展开更多
Decoupling electrical and thermal properties to enhance the figure of merit of thermoelectric materials underscores an in-depth understanding of the mechanisms that govern the transfer of charge carriers.Typically,a f...Decoupling electrical and thermal properties to enhance the figure of merit of thermoelectric materials underscores an in-depth understanding of the mechanisms that govern the transfer of charge carriers.Typically,a factor that contributes to the optimization of thermal conductivity is often found to be detrimental to the electrical transport properties.Here,we systematically investigated 26 dimeric MX_(2)-type compounds(where M represents a metal and X represents a nonmetal element)to explore the influence of the electronic configurations of metal cations on lattice thermal transport and thermoelectric performance using first-principles calculations.A principled scheme has been identified that the filled outer orbitals of the cation lead to a significantly lower lattice thermal conductivity compared to that of the partly occupied case for MX_(2),due to the much weakened bonds manifested by the shallow potential well,smaller interatomic force constants,and higher atomic displacement parameters.Based on these findings,we propose two ionic compounds,BaAs and BaSe_(2),to realize reasonable high electrical conductivities through the structural anisotropy caused by the inserted covalent X_(2) dimers while still maintaining the large lattice anharmonicity.The combined superior electrical and thermal properties of BaSe_(2) lead to a high n-type thermoelectric ZT value of 2.3 at 500 K.This work clarifies the structural origin of the heat transport properties of dimeric MX_(2)-type compounds and provides an insightful strategy for developing promising thermoelectric materials.展开更多
Volatile organic compounds(VOCs)are difficult to be eliminated safely and effectively because of their large concentration fluctuations.Thus,maintaining a stable concentration of VOCs is a significant study.In this re...Volatile organic compounds(VOCs)are difficult to be eliminated safely and effectively because of their large concentration fluctuations.Thus,maintaining a stable concentration of VOCs is a significant study.In this research,H2O,Tween-80,[Emim]BF4,[Emim]PF6,and[Hnmp]HSO4 were applied to absorb and desorb simulated VOCs.The ionic liquid[Emim]BF4 demonstrated the best performance and was thus selected for further experiments.As the ionic liquid acted as a buffer,the toluene concentration with a fluctuation of 2000–20000 mg·m-3 was stabilized at 6000–12000 mg·m-3.Heating distillation(90°C)was highly efficient to recover[Emim]BF4 from toluene.The regenerated[Emim]BF4 could retain its initial absorption capacity even after multiple cycles.Moreover,[Emim]BF4 had the same buffer function on various aromatic hydrocarbons.展开更多
Asymmetric reductive amination of carbonyl compounds was carried out using a novel class of aliphatic quarternary ammonium based chiral ionic liquid. S-(+)-2,3-dihydroxy-N,N,N-tributylpropanaminum bromide chiral ionic...Asymmetric reductive amination of carbonyl compounds was carried out using a novel class of aliphatic quarternary ammonium based chiral ionic liquid. S-(+)-2,3-dihydroxy-N,N,N-tributylpropanaminum bromide chiral ionic liquid has been synthesized, characterized and used for asymmetric reductive amination of carbonyl compounds in the presence of sodium borohydride. These preliminary results are encouraging and advocate dual role of novel ionic liquid as a medium and reducing agent for proficient conversion of ketones to amines, however, reductive amination reaction needs to be established for other substituents.展开更多
Interface engineering is an effective way to improve efficiency and long-term stability of perovskite solar cells(PSCs).Herein,an ionic compound tetrabutylammonium hexafluorophosphate(TP6)is adopted to passivate surfa...Interface engineering is an effective way to improve efficiency and long-term stability of perovskite solar cells(PSCs).Herein,an ionic compound tetrabutylammonium hexafluorophosphate(TP6)is adopted to passivate surface defects of the perovskite film.It is found that TP6 effectively reduced the surface defects,especially at the grain boundaries where the defects are abundant.Meanwhile,the exposed long alkyl chains and fluorine atoms in the TP6 enhanced the moisture stability of the perovskite film due to its strong hydrophobicity.In addition,the driving force of charge carrier separation and transport is increased by enlarged built-in potential.Consequently,the power conversion efficiency(PCE)of PSCs is significantly improved from 20.59% to 22.41%by increased open-circuit voltage(V_(oc))and fill factor(FF).The unencapsulated device with TP6 treatment exhibits better stability than the control device,and the PCE retains-80%of its initial PCE after 30 days under 15%-25%relative humidity in storage,while the PCE of the control device declines by more than 50%.展开更多
The effects of the structure of typical cations and anions of ionic liquids on the separation of benzene and toluene from aromatic/paraffin mixtures were studied. The .results showed that the corresponding separation ...The effects of the structure of typical cations and anions of ionic liquids on the separation of benzene and toluene from aromatic/paraffin mixtures were studied. The .results showed that the corresponding separation factors were considerably larger than those of the traditional solvents （Benzene＋Hexane＋sulfolane）, and that the ionic liquids could be used as novel solvents for the separation of aromatics from hydrocarbon mixtures. The key parameters governing the ability of ionic liquids for separating aromatics from hydrocarbon sources were investigated. It was found that the effectiveness of the ionic liquids, based on the same anion, changed in the cation order of [BIqu]^＋〈 [BPy]^＋〈 [BMIM]^＋. The selectivity of the ionic liquid toward aromatics decreased apparently with the increasing length of the substituted alkyl chain of its cationic head ring. The separation factors, based on the same cation, changed in the anion order of [Tf2N]^-〈[PF6]^-〈[BF4]^-〈[C2H5SO4]^-. The solubilities of the aromatics were greater in the ionic liquids based on the former three anions than that in the ionic liquids involving [C2H5SO4]^-.展开更多
[Hmim]_3PW_(12)O_(40) was developed and used in the acetalization of carbonyl compounds in excellent yields.The ionic liquidheteropoly acid hybrid compound and reaction medium formed temperature-dependent phase-separa...[Hmim]_3PW_(12)O_(40) was developed and used in the acetalization of carbonyl compounds in excellent yields.The ionic liquidheteropoly acid hybrid compound and reaction medium formed temperature-dependent phase-separation system with the ease of product as well as catalyst separation.The catalyst was recycled more than 10 times without any apparent loss of catalytic activity.展开更多
Room temperature ionic liquids(RTILs) are non-volatile organic salts. They may replace conventional coalescing agents in latex coating thus reducing volatile organic compounds(VOCs) emission as well as improving perfo...Room temperature ionic liquids(RTILs) are non-volatile organic salts. They may replace conventional coalescing agents in latex coating thus reducing volatile organic compounds(VOCs) emission as well as improving performance of latex coating products such as better thermal stability, conductivity, and antifouling property. The formation of latex coating containing RTILs can be achieved by encapsulation of RTILs inside particles via miniemulsion polymerization. In this study, the role of RTILs and its concentration on stability of miniemulsion during storage and polymerization were investigated. It has been found that, above a critical concentration(10 wt%), adding more RTILs to oil phase may weaken miniemulsion stability during storage as well as polymerization. Such observations were consistent with the zeta potential measurement for miniemulsions prepared at the similar conditions. The results obtained here would be a useful guideline for the development of new waterborne coating products with desirable functions and particle sizes.展开更多
A protocol for the Knoevenagel condensation of aromatic aldehydes with methylene compounds catalyzed by task specifed ionic liquid 1,8-diazabicyclo[5.4.0]-undec-7-en-8-ium lactate under solvent-free conditions has bee...A protocol for the Knoevenagel condensation of aromatic aldehydes with methylene compounds catalyzed by task specifed ionic liquid 1,8-diazabicyclo[5.4.0]-undec-7-en-8-ium lactate under solvent-free conditions has been developed. The reactions proceed at ambient temperature and the work-up procedures are very simple. Good to excellent yields could be obtained. The ionic liuid could be simply prepared and recycled efficiently.展开更多
Metal-organic frameworks(MOFs)have attracted considerable research attention as a new type of porous material for catalytic applications.Herein,2,5-dihydroxyterephthalic acid was proposed to replace conventional terep...Metal-organic frameworks(MOFs)have attracted considerable research attention as a new type of porous material for catalytic applications.Herein,2,5-dihydroxyterephthalic acid was proposed to replace conventional terephthalic acid and reacted with chromic nitrate nonahydrate to synthesize a functional metal–organic framework(FMIL-101).This was then used to immobilize various compound ionic liquids to prepare three ionic liquids immobilized on FMIL-101 catalysts,namely,FMIL-101-[HeMIM]Cl/(ZnBr_(2))_(2),FMIL-101-[CeMIM]Cl/(ZnBr_(2))_(2),and FMIL-101-[AeMIM]Br/(ZnBr_(2))_(2).After characterization by Fourier-transform infrared spectroscopy,X-ray diffraction,ultraviolet spectroscopy,thermogravimetry,specific surface area analysis,and scanning electron microscopy,the catalysts were used to mediate cycloaddition reactions between carbon dioxide(CO_(2))and propylene oxide.The effects of reaction temperature,reaction pressure,reaction time,and catalyst dosage on the catalytic performance were investigated.The results revealed that the FMIL-101-supported CIL catalysts afforded the target product propylene carbonate with good catalytic performance and thermal stability.The optimal catalyst,FMIL-101-[CeMIM]Cl/(ZnBr_(2))_(2),displayed a propylene oxide conversion of 98.64%and a propylene carbonate selectivity of 96.63%at a reaction temperature of 110℃,a reaction pressure of 2.0 MPa,a catalyst dosage of 2.0%relative to propylene oxide,and a reaction time of 2.5 h.In addition,the conversion and selectivity of the catalyst decreased slightly after four cycles.Additionally,the catalyst decreased slightly in catalytic performance after being recycled four times.展开更多
Nucleophilic aromatic substitution of hydrogen in non-activated aromatic ring,a very rare phenomenon in organic chemistry,is found in ionic liquids containing Cl^- as anion under mild reaction conditions.The reaction ...Nucleophilic aromatic substitution of hydrogen in non-activated aromatic ring,a very rare phenomenon in organic chemistry,is found in ionic liquids containing Cl^- as anion under mild reaction conditions.The reaction may be carried out by the addition of the halogen-bonding adduct（Br2Cl^-） as nucleophile to aromatic ring carbon atom,leading to the formation of the nucleophilic substitution product.展开更多
A catalyst-free, facile and efficient Michael addition reaction of active methylene compounds as well as nitromethane with chalcones catalyzed by guanidinium lactate ionic liquid was done. A series of chalcones, nitro...A catalyst-free, facile and efficient Michael addition reaction of active methylene compounds as well as nitromethane with chalcones catalyzed by guanidinium lactate ionic liquid was done. A series of chalcones, nitromethane, and active methylene compounds were converted smoothly to the corresponding products in high yields. The simple procedure, very mild conditions, high yields, and reuse of the IL without any loss of catalytic activity make this protocol considerably attractive for academic researches and practical applications.展开更多
A series of condensation reactions of unmodified ketones and aromatic aldehydes to prepare α,β-unsaturated carbonyl compounds by means of Aldol reactions in Bronsted acid ionic liquids（BAILs）was explored.1-Butyl-3...A series of condensation reactions of unmodified ketones and aromatic aldehydes to prepare α,β-unsaturated carbonyl compounds by means of Aldol reactions in Bronsted acid ionic liquids（BAILs）was explored.1-Butyl-3-methylimidazolium hydrogen sulphate（BMImHSO4）acting as an effective media and catalyst in aldol reactions was compared with other BAILs,with the advantages of high conversion and selectivity.The product was easily isolated and the left ionic liquid can be readily recovered and reused at least 3 times with almost the same efficiency.The scope and limitation of the present method were explored and the possible catalytic mechanism was speculated.展开更多
文摘A novel ionic compound [Fe（CN）6（phCH2NC5H5）3]·（H2O）4（Mr = 794.71） has been synthesized and its structure was characterized by IR, elemental analysis and X-my diffraction. The compound crystallizes in monoclinic, space group P21/c with a = 10.837（2）, b = 16.551（3）, c = 23.402（5） A, p = 97.531（4）°, V = 4161.0（15） A3, Z = 4, Dc = 1.269 g/cm^3, F（000） = 1668, p = 0.414 mm^-1, R = 0.0479 and wR = 0.1232. The building unit of the title compound consists of three （phCH2N＋C5H5） ions, one [Fe（CN）6]^3- anion and four water molecules. According to the structural analysis, UFe（CN）6]^3- are linked together by O-H…N and O-H…O hydrogen bonds, but UFe（CN）6]^3- and [ （phCH2N＋ C5H5）3] ions are bound by electrostatic force to form an ionic compound.
基金supported by the National Key Research and Development Project from the Ministry of Science and Technology of China (No. 2021YFB3800103)National Natural Science Foundation of China (22209068)+1 种基金General Program of Basic Research in Shenzhen (JCYJ20220530112801004)the Major Program of Guangdong Basic and Applied Research Foundation (Nos. 2019B1515120083, 2019B121205001 and 2019B030302009)。
文摘Inorganic hole transport materials, particularly NiO_X, have shown considerable promise in boosting the efficiency and stability of perovskite solar cells. However, a major barrier to commercialization of NiO_X-based perovskite solar cells with positive-intrinsic-negative architectures is their direct contact with the absorbing layer, which can lead to losses of photovoltage and fill factor. Furthermore, highly positive under-coordinated Ni cations degrade the perovskite at the interface. Here, we address these issues with the use of an ionic compound(QAPyBF_(4)) as an additive to passivate defects throughout the perovskite layer and improve carrier conduction and interactions with under-coordinated Ni cations. Specifically,the highly electronegative inorganic anion [BF_(4)]~- interacts with the NiO_x/perovskite interface to passivate under-coordinated cations(Ni^(≥3+)). Accordingly, the decorated cells achieved a power conversion efficiency of 23.38% and a fill factor of 85.5% without a complex surface treatment or NiO_X doping.
基金supported by the Natural Science Foundation of Education Committee of Henan Province (2006150016)
文摘A novel ionic compound [Fe（CN）6·（PhCHeNC9H7）4]·12H2O（C70H80FeN10O12, Mr = 1309.29） has been synthesized and its structure was characterized by I-R, elemental analysis and X-ray diffraction. The compound crystaUizes in triclinic, space group P1, with a = 10.968（7）, b = 11.466（7）, c = 14.077（8）A, α= 87.014（7）, β= 78.124（7）, γ = 72.708（7）°, V = 1654.1（17）A3, Z = 1, Dc = 1.314 g·cm^-3, F（000） = 692, p = 0.298 mm^-1, the final R = 0.0519 and wR = 0.1355. The building unit of the title compound consists of four （PhCH2N＋C9H7） ions, one [Fe（CN）6]4- anion, and a dozen water molecules. According to the structural analysis, [Fe（CN）6]4- ions are linked together by O-H…O and O-H…N hydrogen bonds, while （PhCH2N＋C9HT） and [Fe（CN）6]4- ions interact with each other by electrostatic force to form an ionic compound.
基金Supported by the Doctoral Fund of Ministry of Education of China(20130181130006)the Key Program of National Natural Science Foundation of China(21336008)the National Natural Science Foundation of China(21476150)
文摘Switchable ionic compounds have wide applications in chemical processes.A switchable ionic compound based on 1,8-diazabicyclo-[5.4.0]-undec-7-ene(DBU),CH_3OH and CO_2 was synthesized and characterized.DBU/CH_3OH/CO_2 ionic compound was prepared in the presence of excess methanol,and then the excess methanol was removed by reduced pressure distillation in CO_2 atmosphere.The product yield(100%) reached the theoretical maximum for the first time.Its structure was identified by NMR,FT-IR,and XRD.The crystal product shows 8strong peaks in XRD at 2θ values of 16.0547°,16.4308°,16.7651°,18.8714°,19.2140°,21.9471°,22.0780°,and25.5661°.Its decomposition onset temperature(53 ℃) was affirmed by TGA,which is lower than its melting point.And its ionic switch point was measured by conductivity.
基金financial support from the Natural Science Foundation of China(No.11904089,12174092,11674087)the Overseas Expertise Introduction Center for Discipline Innovation(D18025)+1 种基金the Program for Key Research and Development of Science and Technology in Hubei Province(grant No.2023BEB002)supported by the Young Science Foundation of Hubei University(Grant No.430/184303000047).
文摘Decoupling electrical and thermal properties to enhance the figure of merit of thermoelectric materials underscores an in-depth understanding of the mechanisms that govern the transfer of charge carriers.Typically,a factor that contributes to the optimization of thermal conductivity is often found to be detrimental to the electrical transport properties.Here,we systematically investigated 26 dimeric MX_(2)-type compounds(where M represents a metal and X represents a nonmetal element)to explore the influence of the electronic configurations of metal cations on lattice thermal transport and thermoelectric performance using first-principles calculations.A principled scheme has been identified that the filled outer orbitals of the cation lead to a significantly lower lattice thermal conductivity compared to that of the partly occupied case for MX_(2),due to the much weakened bonds manifested by the shallow potential well,smaller interatomic force constants,and higher atomic displacement parameters.Based on these findings,we propose two ionic compounds,BaAs and BaSe_(2),to realize reasonable high electrical conductivities through the structural anisotropy caused by the inserted covalent X_(2) dimers while still maintaining the large lattice anharmonicity.The combined superior electrical and thermal properties of BaSe_(2) lead to a high n-type thermoelectric ZT value of 2.3 at 500 K.This work clarifies the structural origin of the heat transport properties of dimeric MX_(2)-type compounds and provides an insightful strategy for developing promising thermoelectric materials.
基金Supported by the Zhejiang University Students Science and Technology Innovation Activity Plan Funding(No.2018R403078).
文摘Volatile organic compounds(VOCs)are difficult to be eliminated safely and effectively because of their large concentration fluctuations.Thus,maintaining a stable concentration of VOCs is a significant study.In this research,H2O,Tween-80,[Emim]BF4,[Emim]PF6,and[Hnmp]HSO4 were applied to absorb and desorb simulated VOCs.The ionic liquid[Emim]BF4 demonstrated the best performance and was thus selected for further experiments.As the ionic liquid acted as a buffer,the toluene concentration with a fluctuation of 2000–20000 mg·m-3 was stabilized at 6000–12000 mg·m-3.Heating distillation(90°C)was highly efficient to recover[Emim]BF4 from toluene.The regenerated[Emim]BF4 could retain its initial absorption capacity even after multiple cycles.Moreover,[Emim]BF4 had the same buffer function on various aromatic hydrocarbons.
文摘Asymmetric reductive amination of carbonyl compounds was carried out using a novel class of aliphatic quarternary ammonium based chiral ionic liquid. S-(+)-2,3-dihydroxy-N,N,N-tributylpropanaminum bromide chiral ionic liquid has been synthesized, characterized and used for asymmetric reductive amination of carbonyl compounds in the presence of sodium borohydride. These preliminary results are encouraging and advocate dual role of novel ionic liquid as a medium and reducing agent for proficient conversion of ketones to amines, however, reductive amination reaction needs to be established for other substituents.
基金funded by the Strategic Priority Research Program of the Chinese Academy of Sciences (Grant No. XDA17040506)the National Key Research and Development Program of China (2017YFA0204800/2016YFA0202403)+6 种基金the Key Program project of the National Natural Science Foundation of China (51933010)the National Natural Science Foundation of China (61974085)the 111 Project (B21005)the Changjiang Scholars and Innovative Research Team (IRT_14R33)the National University Research Fund (GK201903051)the Research Start-up Fund from Shaanxi Normal University (1110020142)the Shanxi Science and Technology Department (20201101012).
文摘Interface engineering is an effective way to improve efficiency and long-term stability of perovskite solar cells(PSCs).Herein,an ionic compound tetrabutylammonium hexafluorophosphate(TP6)is adopted to passivate surface defects of the perovskite film.It is found that TP6 effectively reduced the surface defects,especially at the grain boundaries where the defects are abundant.Meanwhile,the exposed long alkyl chains and fluorine atoms in the TP6 enhanced the moisture stability of the perovskite film due to its strong hydrophobicity.In addition,the driving force of charge carrier separation and transport is increased by enlarged built-in potential.Consequently,the power conversion efficiency(PCE)of PSCs is significantly improved from 20.59% to 22.41%by increased open-circuit voltage(V_(oc))and fill factor(FF).The unencapsulated device with TP6 treatment exhibits better stability than the control device,and the PCE retains-80%of its initial PCE after 30 days under 15%-25%relative humidity in storage,while the PCE of the control device declines by more than 50%.
基金The authors thank the National Natural Science Foundation of China(20276037)the CNPC Innovation Foundation(03E7016)for financial support.
文摘The effects of the structure of typical cations and anions of ionic liquids on the separation of benzene and toluene from aromatic/paraffin mixtures were studied. The .results showed that the corresponding separation factors were considerably larger than those of the traditional solvents （Benzene＋Hexane＋sulfolane）, and that the ionic liquids could be used as novel solvents for the separation of aromatics from hydrocarbon mixtures. The key parameters governing the ability of ionic liquids for separating aromatics from hydrocarbon sources were investigated. It was found that the effectiveness of the ionic liquids, based on the same anion, changed in the cation order of [BIqu]^＋〈 [BPy]^＋〈 [BMIM]^＋. The selectivity of the ionic liquid toward aromatics decreased apparently with the increasing length of the substituted alkyl chain of its cationic head ring. The separation factors, based on the same cation, changed in the anion order of [Tf2N]^-〈[PF6]^-〈[BF4]^-〈[C2H5SO4]^-. The solubilities of the aromatics were greater in the ionic liquids based on the former three anions than that in the ionic liquids involving [C2H5SO4]^-.
基金support from Nanjing University of Science and Technology
文摘[Hmim]_3PW_(12)O_(40) was developed and used in the acetalization of carbonyl compounds in excellent yields.The ionic liquidheteropoly acid hybrid compound and reaction medium formed temperature-dependent phase-separation system with the ease of product as well as catalyst separation.The catalyst was recycled more than 10 times without any apparent loss of catalytic activity.
基金the Low Carbon Automation Manufacture Innovation Team 2011B81006 for the PhD studentshipNingbo Natural Science Foundation funding 2012A610094
文摘Room temperature ionic liquids(RTILs) are non-volatile organic salts. They may replace conventional coalescing agents in latex coating thus reducing volatile organic compounds(VOCs) emission as well as improving performance of latex coating products such as better thermal stability, conductivity, and antifouling property. The formation of latex coating containing RTILs can be achieved by encapsulation of RTILs inside particles via miniemulsion polymerization. In this study, the role of RTILs and its concentration on stability of miniemulsion during storage and polymerization were investigated. It has been found that, above a critical concentration(10 wt%), adding more RTILs to oil phase may weaken miniemulsion stability during storage as well as polymerization. Such observations were consistent with the zeta potential measurement for miniemulsions prepared at the similar conditions. The results obtained here would be a useful guideline for the development of new waterborne coating products with desirable functions and particle sizes.
基金Supported by the National Natural Science Foundation of China(No.20776127)the National Key Technology Research and Development Program of China(No.2007BAI34B07)
文摘A protocol for the Knoevenagel condensation of aromatic aldehydes with methylene compounds catalyzed by task specifed ionic liquid 1,8-diazabicyclo[5.4.0]-undec-7-en-8-ium lactate under solvent-free conditions has been developed. The reactions proceed at ambient temperature and the work-up procedures are very simple. Good to excellent yields could be obtained. The ionic liuid could be simply prepared and recycled efficiently.
基金supported by the National Natural Science Foundation of China (Grant No.22278271)the Key Project of Education Department of Liaoning Province(Grant No.LZGD2020005)
文摘Metal-organic frameworks(MOFs)have attracted considerable research attention as a new type of porous material for catalytic applications.Herein,2,5-dihydroxyterephthalic acid was proposed to replace conventional terephthalic acid and reacted with chromic nitrate nonahydrate to synthesize a functional metal–organic framework(FMIL-101).This was then used to immobilize various compound ionic liquids to prepare three ionic liquids immobilized on FMIL-101 catalysts,namely,FMIL-101-[HeMIM]Cl/(ZnBr_(2))_(2),FMIL-101-[CeMIM]Cl/(ZnBr_(2))_(2),and FMIL-101-[AeMIM]Br/(ZnBr_(2))_(2).After characterization by Fourier-transform infrared spectroscopy,X-ray diffraction,ultraviolet spectroscopy,thermogravimetry,specific surface area analysis,and scanning electron microscopy,the catalysts were used to mediate cycloaddition reactions between carbon dioxide(CO_(2))and propylene oxide.The effects of reaction temperature,reaction pressure,reaction time,and catalyst dosage on the catalytic performance were investigated.The results revealed that the FMIL-101-supported CIL catalysts afforded the target product propylene carbonate with good catalytic performance and thermal stability.The optimal catalyst,FMIL-101-[CeMIM]Cl/(ZnBr_(2))_(2),displayed a propylene oxide conversion of 98.64%and a propylene carbonate selectivity of 96.63%at a reaction temperature of 110℃,a reaction pressure of 2.0 MPa,a catalyst dosage of 2.0%relative to propylene oxide,and a reaction time of 2.5 h.In addition,the conversion and selectivity of the catalyst decreased slightly after four cycles.Additionally,the catalyst decreased slightly in catalytic performance after being recycled four times.
基金the key project of Shanghai Science and Technology Committee(Nos.05JC14070,06DZ05025, 08JC1408600) for financial supports
文摘Nucleophilic aromatic substitution of hydrogen in non-activated aromatic ring,a very rare phenomenon in organic chemistry,is found in ionic liquids containing Cl^- as anion under mild reaction conditions.The reaction may be carried out by the addition of the halogen-bonding adduct（Br2Cl^-） as nucleophile to aromatic ring carbon atom,leading to the formation of the nucleophilic substitution product.
文摘A catalyst-free, facile and efficient Michael addition reaction of active methylene compounds as well as nitromethane with chalcones catalyzed by guanidinium lactate ionic liquid was done. A series of chalcones, nitromethane, and active methylene compounds were converted smoothly to the corresponding products in high yields. The simple procedure, very mild conditions, high yields, and reuse of the IL without any loss of catalytic activity make this protocol considerably attractive for academic researches and practical applications.
基金Supported by National Natural Science Foundation of China(No.20576026)Environmental Engineering Key Subject of He-bei Province,China.
文摘A series of condensation reactions of unmodified ketones and aromatic aldehydes to prepare α,β-unsaturated carbonyl compounds by means of Aldol reactions in Bronsted acid ionic liquids（BAILs）was explored.1-Butyl-3-methylimidazolium hydrogen sulphate（BMImHSO4）acting as an effective media and catalyst in aldol reactions was compared with other BAILs,with the advantages of high conversion and selectivity.The product was easily isolated and the left ionic liquid can be readily recovered and reused at least 3 times with almost the same efficiency.The scope and limitation of the present method were explored and the possible catalytic mechanism was speculated.
