Available online An efficient method for the synthesis of multi-substituted cyclic imides was developed with cyanoesters and diaryliodonium salts.This method proceeds through a cascade of N-arylationacylation and rear...Available online An efficient method for the synthesis of multi-substituted cyclic imides was developed with cyanoesters and diaryliodonium salts.This method proceeds through a cascade of N-arylationacylation and rearrangement to give target heterocycles in good yields(up to 99%).This method has the major advantages of a broad substrate scope,excellent functional group compatibility.The strategy was also extended to the fused cyclic imides,such as malonimides,succinimides and glutarimides.展开更多
The kinetics of reaction between cyclic monoimides (succinimide, phtalimide, and glutarimide) with ethylene and propylene oxides in presence of sodium hydroxide was studied. The effect of substrate and catalyst concen...The kinetics of reaction between cyclic monoimides (succinimide, phtalimide, and glutarimide) with ethylene and propylene oxides in presence of sodium hydroxide was studied. The effect of substrate and catalyst concentrations on the course of the reaction was investigated. Kinetics of reaction was studied by dilatometry, i.e. by measuring volume contraction of reaction mixture. The kinetic law describing the reaction of imides with oxiranes is: . where ccat, cAH and cB are concentrations of catalyst, imide, and oxirane, respectively. The relative reactivity of imides and oxiranes was: GI > PI ≥ SI and EO > PO. The reaction mechanism was proposed based upon experimentally determined rate law for the reaction of cyclic monoimides and oxiranes as well as analytical and instrumental analysis of products. The elementary reaction between oxirane and imide anion is rate determining step. The imide anion is formed by hydrogen cation transfer into catalytic hydroxide anion from dissociated NaOH. In the consecutive elemental reaction an imidate anion attack on the oxirane molecule occurs. It is the slowest stage of the reaction, limiting the entire process. All the studied reactions obey the same mechanism as can be concluded from isokinetic relationship of studied systems)展开更多
Literature describes kinetics of reactions of alcohols, phenols, carboxylic acids, amines and amides with oxiranes such as ethylene oxide and propylene oxide. However, there is no information regarding kinetic of reac...Literature describes kinetics of reactions of alcohols, phenols, carboxylic acids, amines and amides with oxiranes such as ethylene oxide and propylene oxide. However, there is no information regarding kinetic of reaction of imides with oxiranes. In this article the kinetics of the reaction of cyclic monoimides: succinimide, phtalimide, and glutarimide, with ethylene and propylene oxides in presence of triethylamine in aprotic solvent was studied. The rate laws for those processes were established based upon on dilatometric measurements. I was said that cyclic monoimides react with oxiranes in presence of triethylamine to give N-(2-hydroxyalkyl)imides as major product. This product react further with oxiranes in consecutive reaction. The kinetics of the reaction of cyclic mono-imides with oxiranes obey the following rate law: V = k1/2 c1/2cat c3/2imide c1/2oxirane. Based upon kinetic data the following orders of reactivity of imides and oxiranes were obtained: phtalimide ≥ succinimide > glutarimide and ethylene oxide > propylene oxide. The solvent (DMF, DMSO and dioxane) effect was also studied. From temperature dependences the thermodynamic parameters: activation energy, enthalpy and entropy from linear Eyring plots were obtained.展开更多
The mechanism of reaction of cyclic monoimides with oxiranes was established based upon kinetic studies and product analysis. It has been established that the reaction proceeds through initial formation of an adduct o...The mechanism of reaction of cyclic monoimides with oxiranes was established based upon kinetic studies and product analysis. It has been established that the reaction proceeds through initial formation of an adduct of imide and triethylamine. The crucial bond in adduct has ionic character;in non-aqueous solvents it is present as ion pair, while in water the adduct dissociate and free ions are present. The adduct enables the proton transfer from imide to oxirane. The rate determining step is reaction of imide and this adduct. Different values of entropy of transition states obtained from thermodynamic calculations suggest slightly different structure of transition state of rate determining step.展开更多
Polyimides are well-known for their high chemical inertness and thermal stability. However, it is usually challenging to synthesize UV-curable polyimides since the imidization reaction requires such harsh conditions t...Polyimides are well-known for their high chemical inertness and thermal stability. However, it is usually challenging to synthesize UV-curable polyimides since the imidization reaction requires such harsh conditions that acrylate type double bonds cannot withstand. In this work, synthetic methods are developed to obtain polyester-imide type binder polymers with high thermal stability, high compatibility with the other components of the black photoresist, and fine photolithographic patterning property for the negative-tone black photoresist. The syntheses of diimide-diacid or diimide-diol intermediates for the polyesterification with dianhydride gave polyester imides which meets this requirement. The photolithographic tests have shown that the patterning of the micron-sized PDL of the organic light emitting diode (OLED) panel could be obtained. This work will interest the researchers working on the design and optimization of thermally stable binder polymers.展开更多
The direct transformation of dinitrogen(N_(2)) into nitrogen-containing organic compounds holds substantial importance.In this work,we report a titanium-promoted method for the conversion of N_(2) to N-methylimides.In...The direct transformation of dinitrogen(N_(2)) into nitrogen-containing organic compounds holds substantial importance.In this work,we report a titanium-promoted method for the conversion of N_(2) to N-methylimides.Initially,the N_(2)-bridging end-on dititanium side-on dipotassium complex[{(Tren^(TMS))Ti}_(2)(μ-η^(1):η^(1):η^(2):η^(2)-N_(2)K_(2))] underwent simultaneous disproportionation and N-methylation reactions in the presence of methyl trifluoromethanesulfonate(Me OTf),yielding [{(N^(Me,TMS)NN^(TMS)_(2))Ti}(μ-NMe)]_(2) with complete cleavage of the N≡N bond.The nucleophilicity of the N-methylated intermediate allowed it to react with electrophilic reagents such as trimethylchlorosilane(TMSCl) to form heptamethyldisilazane,or with acyl chlorides to generate N-methylimides.Moreover,nitrogen-15(^(15)N) labeled experiments provided a novel approach to synthesizing ^(15)N-labeled methylimides.展开更多
CONSPECTUS:Chiral molecular carbon imides(CMCIs)represent a kind of chiralπ-conjugated molecules that are typically designed and synthesized by introducing helical chirality.This approach creates a stereogenic axis,r...CONSPECTUS:Chiral molecular carbon imides(CMCIs)represent a kind of chiralπ-conjugated molecules that are typically designed and synthesized by introducing helical chirality.This approach creates a stereogenic axis,rather than a traditional chiral center or chiral axis with saturated bonds,resulting in chiral conjugated helices(CCHs).CMCIs have garnered significant attention due to their flexible synthesis(annulativeπ-extension strategies),tailor-made structures(chiral polycyclicπ-conjugated frameworks),and diverse properties(optical,electronic,magnetic,and biochemical characteristics related to chirality).Furthermore,CMCI systems exhibit unique chiroptical properties,including circular dichroism(CD)and circularly polarized luminescence(CPL),which have elevated them as emerging stars among chiral organic functional molecules.Benefiting from their large conjugation planes and excellent electron-withdrawing ability,CMCIs often display outstanding electron mobility,high electron affinity,and strong light absorption or emission capabilities,making them valuable in various organic semiconductor applications.Their unique chiroptical properties and excellent semiconducting abilities position CMCIs as key players in the emerging field of chiral optoelectronics.Additionally,the appropriate packing modes and efficient charge transfer in solid-state CCHs provide excellent platforms for applications in chiral-induced spin selectivity(CISS)and topological quantum properties.In this Account,we present a comprehensive overview of three representative types of CMCIs:single-strand CCHs(ss-CCHs),double-strand CCHs(ds-CCHs),and multiple-strand CCHs(ms-CCHs).We focus on their rational design strategies,fundamental chiroptical properties,and chiral optoelectronic applications,particularly in circularly polarized organic photodetectors(CP-OPDs).We also discuss key parameters for evaluating chiroptical performance,such as the luminescence dissymmetry factor(glum)and photoluminescence quantum yield(ΦPL),and explore how the magnetic transition dipole moment(m),together with the electric transition dipole moment(μ),influence glum andΦPL.Through this review,we highlight successful strategies to enhance chiroptical responses,such as improvements in molecular symmetry,heteroannulation,and the introduction of multiple chiral centers.We also delve into the intrinsic correlation between chiral structure and excited-state parameters,supported by theoretical calculations.By emphasizing the judicious structure evolution of high-efficiency circularly polarized photoluminescence(CPPL)in solutions based on these CCHs,we offer perspectives on the future development of circularly polarized electroluminescence(CPEL)emitters and their potential applications in circularly polarized organic light-emitting diodes(CP-OLEDs),which would be more practical for future displays and photonic technologies.Finally,we emphasize the promising prospects of CCHs in multi-functional spin-polarized optoelectronic devices,aiming to achieve room-temperature,long-distance spin transport by leveraging the unique chiral-induced spin selectivity(CISS)effect and outstanding optoelectrical performance.展开更多
Poly(heptazine imide)(PHI),a new allotrope of heptazine-based carbon nitride,is usually synthesized in the presence of binary molten salts(e.g.,LiCl/NaCl,LiCl/KCl,NaCl/KCl)with diverse melting points and solvation abi...Poly(heptazine imide)(PHI),a new allotrope of heptazine-based carbon nitride,is usually synthesized in the presence of binary molten salts(e.g.,LiCl/NaCl,LiCl/KCl,NaCl/KCl)with diverse melting points and solvation abilities.However,the quantum efficiency of PHI for photocatalytic hydrogen production is still extremely restrained.Herein,a series of ternary molten salt mixtures(LiCl/NaCl/KCl)with varying compositions and properties,were employed for the rational control of the polymerization process of PHI and thus optimization in the optical properties,charge separation behaviors,and also photocatalytic performance.The results indicate that the ternary molten salts provide suitable environment for the development of a nanorod morphology,which significantly improves separation of photo-induced charge carriers.Hence,the optimized PHI presents a high apparent quantum yield(AQY=52.9%)for visible-light driven hydrogen production.展开更多
A new protocol for the synthesis of imides has been developed. In the presence of copper catalyst, N-benzylamideswere oxidized to the corresponding imides by TBHP/TEMPO system in moderate to good yields.
Bis[（perfluoroalkyl）sulfonyl]imides [HN（SO2Rf）2, and Rf represents the perfluorinated alkyl group] supported on MCM-41 were synthesized and characterized by XRD, FTIR, SEM, TGA and N2-adsorption techniques. The su...Bis[（perfluoroalkyl）sulfonyl]imides [HN（SO2Rf）2, and Rf represents the perfluorinated alkyl group] supported on MCM-41 were synthesized and characterized by XRD, FTIR, SEM, TGA and N2-adsorption techniques. The supported catalysts, HN（SO2Rf）2/MCM-41, were used as the catalysts for the tert-butylafion of hydroquinone （HQ） with tert-butyl alcohol （TBA） in the liquid phase. A high yield （52.0%） of 2-tert-butyl hydroquinone （TBHQ） could be obtained in the presence of 5 tool% HN（SO2C4F9）2/MCM-41 under the optimized reaction conditions and the heterogeneous catalyst could be recycled at least 6 times without substantial loss of activity.展开更多
2-substituted-1-amino-o-carboranes 2-R-1-NH_(2)-o-C_(2)B_(10)H_(10)(R=CH_(3),1a;R=Ph,1b)were synthesized and the reactions of these compounds with the yttrium dialkyl complex[Y(L)(CH_(2)SiMe3)_(2)](L=[2-(2,5-Me_(2)C_(...2-substituted-1-amino-o-carboranes 2-R-1-NH_(2)-o-C_(2)B_(10)H_(10)(R=CH_(3),1a;R=Ph,1b)were synthesized and the reactions of these compounds with the yttrium dialkyl complex[Y(L)(CH_(2)SiMe3)_(2)](L=[2-(2,5-Me_(2)C_(4)H_(2)N)C_(6)H4NC(Ph)=NDipp]-,Dipp=2,6-iPr_(2)C_(6)H_(3))were investigated.The 1H NMR spectroscopy indicate that the reaction of ytrrium dialkyl complex with one equivalent of 2-R-1-NH_(2)-o-C_(2)B_(10)H_(10) produce the mixture of ytrrium alkyl-amido complex[Y(L)(2-R-1-NH-o-C_(2)B_(10)H_(10))(CH_(2)SiMe3)](R=CH_(3),2a;R=Ph,2b)and bis(amido)complex[Y(L)(2-R-1-NH-o-C_(2)B_(10)H_(10))_(2)](R=CH_(3),3a;R=Ph,3b).The yttrium bridging imido complex[Y(L)(2-CH_(3)-1-N-o-C_(2)B_(10)H_(10))]_(2)(4a)was obtained by heating the mixture at 55℃for 12 h.Complex 3a was isolated and characterized by treating the yttrium dialkyl complex with two equivalents of 1a.The structures of complexes 3a and 4a were verified by single-crystal Xray diffraction.CCDC:2424136,3a;2424137,4a.展开更多
Glycosyl imidates are among the pioneering donors for catalytic glycosylation.We report a new generation of imidates featuring the presence of a pentafluorophenyl group,introduced via substitution on imidoyl fluoride ...Glycosyl imidates are among the pioneering donors for catalytic glycosylation.We report a new generation of imidates featuring the presence of a pentafluorophenyl group,introduced via substitution on imidoyl fluoride which is easily prepared,stable and user-friendly.The resulting donors exhibit exceptional shelf stability while can be readily activated to achieve high-yielding glycosylation,encompassing comprehensively aldosyl,ketosyl and ulosonyl donors,and both O-and N-glycosylation acceptors.Notably,the reactivity gradient across different generations of imidates,coupled with the accessible imidate acceptor from selective reaction of imidoyl fluoride at the anomeric hydroxyl group,enables a fully catalytic one-pot synthesis of oligosaccharides.展开更多
The major challenge in photocatalytic water splitting lies in water oxidation reactions,which still suffer from poor charge separation.This study overcame inefficient charge separation by establishing a robust interfa...The major challenge in photocatalytic water splitting lies in water oxidation reactions,which still suffer from poor charge separation.This study overcame inefficient charge separation by establishing a robust interfacial electric field through the electrostatic-driven assembly of Co_(3)O_(4) nanoparticles with a perylene imide supramolecule(PDINH).The well-aligned band structures and intimate interfacial contact in the PDINH/Co_(3)O_(4) heterostructure create an enhanced interfacial electric field that is 4.1-and 53.2-fold stronger than those of individual PDINH and Co_(3)O_(4),thus promoting directional charge separation and transfer.Moreover,S-scheme charge transfer strongly preserves the oxidative holes in PDINH to drive efficient water oxidation reactions.Consequently,PDINH/Co_(3)O_(4) composite achieves a photocatalytic oxygen evolution rate of 29.26 mmol g^(–1) h^(–1) under visible light irradiation,8.2-fold improvement over pristine PDINH,with an apparent quantum yield of 6.66%at 420 nm.This study provides fundamental insights into interfacial electric field control for the development of high-performance organic photocatalysts for efficient water oxidation.展开更多
N-Methyl-N-propylpiperidiniumbis（trifluoromethanesulfonyl）imide （PP13TFSI）, bis（triflu- oromethanesulfonyl）imide lithium salt （LiTFSI）, and poly（vinylidene difluoride-co- hexafluoropropylene） （P（VdF-HFP）...N-Methyl-N-propylpiperidiniumbis（trifluoromethanesulfonyl）imide （PP13TFSI）, bis（triflu- oromethanesulfonyl）imide lithium salt （LiTFSI）, and poly（vinylidene difluoride-co- hexafluoropropylene） （P（VdF-HFP）） were mixed and made into ionic liquid gel polymer electrolytes （ILGPEs） by solution casting. The morphology of ILGPEs was observed by scanning electron microscopy. It was found that the ILGPE had a loosened structure with liquid phase uniformly distributed. The ionic conductivity, lithium ion transference num- bet and electrochemical window were measured by electrochemical impedance spectroscopy, chronoamperometric and linear sweep voltammetry. The ionic conductivity and lithium ion transference number of this ILGPE reached 0.79 mS/cm and 0.71 at room temperature, and the electrochemical window was 0 to 5.1 V vs. Li＋/Li. Battery tests indicated that the ILGPE is stable when being operated in Li/LiFePO4 batteries. The discharge capacity maintained at about 135, 117, and 100 mAh/g at 30, 75, and 150 mA/g rates, respectively. The capacity retentions were almost 100% after 100 cycles without little capacity fading.展开更多
The thermal and mechanical properties of the chemically imidized polyimide(CIPI) films and thermally imidized polyimide(TIPI) films were investigated systematically. Experimental results indicated that the CIPI films ...The thermal and mechanical properties of the chemically imidized polyimide(CIPI) films and thermally imidized polyimide(TIPI) films were investigated systematically. Experimental results indicated that the CIPI films show dramatically enhanced tensile strength and modulus with obviously reduced coefficient of thermal expansion(CTE) in comparison with TIPI films. These enhancements results from the high in-plane orientation and close packing of the CIPI backbones. Compared with thermal imidization which starts at about 140 °C, the chemical imidization activated by acetic anhydride and isoquinoline initiates the cyclization even at room temperature.The resulting imide rings restrict the mobility of polymer chains and lead to the in-plane orientation with solvent evaporation.Additionally, fewer small molecules remain in the films after treated at 120 °C by chemical imidization than by thermal imidization. The polymer chain plasticization caused by the evaporation of small molecules at high temperature is obviously restricted. Moreover, the partially imidized polymer inhibits the decomposition of mainchains that occurs at subsequent high temperature process, being beneficial to the formation of high molecular weight PI films. Hence, chemical imidization pathway shows apparent advantage to produce PI films with great combined properties, including high modulus, strength and toughness, as well as high thermal dimension stability etc.展开更多
Nowadays,lithium-ion capacitors(LICs) have become a type of important electrochemical energy storage devices due to their high power and long cycle life characteristics with fast response time.As one of the essential ...Nowadays,lithium-ion capacitors(LICs) have become a type of important electrochemical energy storage devices due to their high power and long cycle life characteristics with fast response time.As one of the essential components of LICs,the electrolytes not only provide the anions and cations required during charge and discharge processes,but also supply the liquid environment for ions to migrate between anodes and cathodes in LIC cells.It is well accepted that propylene carbonate(PC) cannot be used as a single solvent for Li-ion electrolyte due to the failure to form stable SEI film on graphite surface.In this work,the compatibility of PC-based electrolyte with commercial soft carbon anode and activated carbon cathode has been validated by using the laminated pouch LIC cells.The effects of additives on the electrochemical properties of PC-based LICs have been systematically investigated.Ethylene sulfite(ES) was proved to be an effective additive to promote capacity retention at high C-rate,which is superior to vinylene carbonate and fluoroethylene carbonate.The addition of 5 wt% ES plays an important role in reducing internal resistance,as well as improving electrochemical stability and low-temperature performances.This study is expected to be beneficial to explore robust electrolyte/additive combinations for LICs to reduce the internal resistance and to improve the lowtemperature performances.展开更多
Development of active and non-noble metal-based catalyst for H2 production via NH3 decomposition is crucial for the implementation of NH3 as a H2 carrier.Co-based catalysts have received increasing attention because o...Development of active and non-noble metal-based catalyst for H2 production via NH3 decomposition is crucial for the implementation of NH3 as a H2 carrier.Co-based catalysts have received increasing attention because of its high intrinsic activity and moderate cost.In this work,we examined the effect of BaNH,CaNH and Mg3 N2 on the catalytic activity of Co in the NH3 decomposition reaction.The H2 formation rate ranks the order as Co-BaNH>Co-CaNH>Co-Mg3 N2≈Co/CNTs within a reaction temperature range of 300-550℃.It is worth pointing out that the H2 formation rate of Co-BaNH at 500℃reaches20 mmolH2 gcat-1 min-1,which is comparable to those of the active Ru/Al2 O3(ca.17 mmolH2 gcat-1 min1)and Ru/AC(21 mmolH2 gcat-1 min-1)catalysts under the similar reaction conditions.In-depth research shows that Co-BaNH exhibits an obviously higher intrinsic activity and much lower Ea(46.2 kJ mol-1)than other Co-based catalysts,suggesting that BaNH may play a different role from CaNH,Mg3 N2 and CNTs during the catalytic process.Combined results of XRD,Ar-TPD and XAS show that a[Co-N-Ba]-like intermediate species is likely formed at the interface of Co metal and BaNH,which may lead to a more energy-efficient reaction pathway than that of neat Co metal for NH3 decomposition.展开更多
Composite polymer electrolytes based on mixing soft-segment waterborne polyurethane （WPU） and 1-butyl-3-methylimidazolium bis[（trifluoromethyl）sulfonyl]imide （BMImTFSI） have been prepared and characterized. The ...Composite polymer electrolytes based on mixing soft-segment waterborne polyurethane （WPU） and 1-butyl-3-methylimidazolium bis[（trifluoromethyl）sulfonyl]imide （BMImTFSI） have been prepared and characterized. The addition of BMImTFSI results in an increase of the ionic conductivity. At high BMImTFSI concentration （BMImTFSI/WPU = 3 in weight ratio）, the ionic conductivity reaches 4.27 × 10^-3 S/cm at 30 ℃. These composite polymer electrolytes exhibit good thermal and electrochemical stability, which are high enough to be applied in lithium batteries.展开更多
In this study, polyimide fibers at different stages of imidization were characterized by TGA, DSC, and FTIR. The imidization degree （ID） calculated by TGA was based on the weight loss of each sample, which was cause...In this study, polyimide fibers at different stages of imidization were characterized by TGA, DSC, and FTIR. The imidization degree （ID） calculated by TGA was based on the weight loss of each sample, which was caused by the imidization of residual amic acid groups. The results of TGA showed good regularity with the thermal treatment temperature of the PI fibers. For DSC, the ID was calculated based on the area of endothermal peak of each sample. Compared with TGA, DSC showed a relatively higher value because the endothermal peak was reduced by the exothermic re-formation of polyamic acid which may be partially degraded during thermal treatment. The IDs obtained by the FTIR spectra generally showed poorer regularities than those obtained by both TGA and DSC, especially for the results calculated using the 730 cm^-1 band. Based on the 1350 cm^-1 band, the obtained IDs showed better agreement with the TGA or DSC results. The results obtained by these three methods were compared and analyzed. The ID obtained by TGA showed much more reliability among these three methods.展开更多
A series of novel aromatic poly ( amide imide)s containing phthalazinone moieties were prepared from 2-(4-aminophenyl)-4-[3-methyl-4-(4-aminophenoxy)-2,3-phthalazinone-1], a novel diamine 1 with four diimide-dicarboxy...A series of novel aromatic poly ( amide imide)s containing phthalazinone moieties were prepared from 2-(4-aminophenyl)-4-[3-methyl-4-(4-aminophenoxy)-2,3-phthalazinone-1], a novel diamine 1 with four diimide-dicarboxylic acids by Yamazaki phosphorylation method with the inherent viscosity of 0.36~0.65 dL/g. These polymers had high glass transition temperatures above 300C and they lost 10% weight between 426~475C in N2. The structure of diamine 1 and the polymers was confirmed by IR, 1H NMR and MS. The obtained polymers were readily soluble in polar solvents such as NMP, m-cresol etc. and easily cast into tough, flexible films. The X-ray indicated that they are all amorphous.展开更多
基金supported by the National Natural Science Foundation of China(Nos.21871158 and 22071129)。
文摘Available online An efficient method for the synthesis of multi-substituted cyclic imides was developed with cyanoesters and diaryliodonium salts.This method proceeds through a cascade of N-arylationacylation and rearrangement to give target heterocycles in good yields(up to 99%).This method has the major advantages of a broad substrate scope,excellent functional group compatibility.The strategy was also extended to the fused cyclic imides,such as malonimides,succinimides and glutarimides.
文摘The kinetics of reaction between cyclic monoimides (succinimide, phtalimide, and glutarimide) with ethylene and propylene oxides in presence of sodium hydroxide was studied. The effect of substrate and catalyst concentrations on the course of the reaction was investigated. Kinetics of reaction was studied by dilatometry, i.e. by measuring volume contraction of reaction mixture. The kinetic law describing the reaction of imides with oxiranes is: . where ccat, cAH and cB are concentrations of catalyst, imide, and oxirane, respectively. The relative reactivity of imides and oxiranes was: GI > PI ≥ SI and EO > PO. The reaction mechanism was proposed based upon experimentally determined rate law for the reaction of cyclic monoimides and oxiranes as well as analytical and instrumental analysis of products. The elementary reaction between oxirane and imide anion is rate determining step. The imide anion is formed by hydrogen cation transfer into catalytic hydroxide anion from dissociated NaOH. In the consecutive elemental reaction an imidate anion attack on the oxirane molecule occurs. It is the slowest stage of the reaction, limiting the entire process. All the studied reactions obey the same mechanism as can be concluded from isokinetic relationship of studied systems)
文摘Literature describes kinetics of reactions of alcohols, phenols, carboxylic acids, amines and amides with oxiranes such as ethylene oxide and propylene oxide. However, there is no information regarding kinetic of reaction of imides with oxiranes. In this article the kinetics of the reaction of cyclic monoimides: succinimide, phtalimide, and glutarimide, with ethylene and propylene oxides in presence of triethylamine in aprotic solvent was studied. The rate laws for those processes were established based upon on dilatometric measurements. I was said that cyclic monoimides react with oxiranes in presence of triethylamine to give N-(2-hydroxyalkyl)imides as major product. This product react further with oxiranes in consecutive reaction. The kinetics of the reaction of cyclic mono-imides with oxiranes obey the following rate law: V = k1/2 c1/2cat c3/2imide c1/2oxirane. Based upon kinetic data the following orders of reactivity of imides and oxiranes were obtained: phtalimide ≥ succinimide > glutarimide and ethylene oxide > propylene oxide. The solvent (DMF, DMSO and dioxane) effect was also studied. From temperature dependences the thermodynamic parameters: activation energy, enthalpy and entropy from linear Eyring plots were obtained.
文摘The mechanism of reaction of cyclic monoimides with oxiranes was established based upon kinetic studies and product analysis. It has been established that the reaction proceeds through initial formation of an adduct of imide and triethylamine. The crucial bond in adduct has ionic character;in non-aqueous solvents it is present as ion pair, while in water the adduct dissociate and free ions are present. The adduct enables the proton transfer from imide to oxirane. The rate determining step is reaction of imide and this adduct. Different values of entropy of transition states obtained from thermodynamic calculations suggest slightly different structure of transition state of rate determining step.
文摘Polyimides are well-known for their high chemical inertness and thermal stability. However, it is usually challenging to synthesize UV-curable polyimides since the imidization reaction requires such harsh conditions that acrylate type double bonds cannot withstand. In this work, synthetic methods are developed to obtain polyester-imide type binder polymers with high thermal stability, high compatibility with the other components of the black photoresist, and fine photolithographic patterning property for the negative-tone black photoresist. The syntheses of diimide-diacid or diimide-diol intermediates for the polyesterification with dianhydride gave polyester imides which meets this requirement. The photolithographic tests have shown that the patterning of the micron-sized PDL of the organic light emitting diode (OLED) panel could be obtained. This work will interest the researchers working on the design and optimization of thermally stable binder polymers.
基金Financial supports from the National Natural Science Foundation of China (Nos.22025109,22371283)the National Key R&D Program of China (No.2023YFA1507902)+1 种基金CAS Project for Young Scientists in Basic Research (No.YSBR-050)the State Key Laboratory of Fine Chemicals,Dalian University of Technology (No.KF2102) are gratefully acknowledged。
文摘The direct transformation of dinitrogen(N_(2)) into nitrogen-containing organic compounds holds substantial importance.In this work,we report a titanium-promoted method for the conversion of N_(2) to N-methylimides.Initially,the N_(2)-bridging end-on dititanium side-on dipotassium complex[{(Tren^(TMS))Ti}_(2)(μ-η^(1):η^(1):η^(2):η^(2)-N_(2)K_(2))] underwent simultaneous disproportionation and N-methylation reactions in the presence of methyl trifluoromethanesulfonate(Me OTf),yielding [{(N^(Me,TMS)NN^(TMS)_(2))Ti}(μ-NMe)]_(2) with complete cleavage of the N≡N bond.The nucleophilicity of the N-methylated intermediate allowed it to react with electrophilic reagents such as trimethylchlorosilane(TMSCl) to form heptamethyldisilazane,or with acyl chlorides to generate N-methylimides.Moreover,nitrogen-15(^(15)N) labeled experiments provided a novel approach to synthesizing ^(15)N-labeled methylimides.
基金financially supported by the National Natural Science Foundation of China(NSFC)(Nos.22122503,22235005,and 22275112)the Postdoctoral Fellowship Program of CPSF(grant nos.2023M741168,2023TQ0116,and GZB20230213)。
文摘CONSPECTUS:Chiral molecular carbon imides(CMCIs)represent a kind of chiralπ-conjugated molecules that are typically designed and synthesized by introducing helical chirality.This approach creates a stereogenic axis,rather than a traditional chiral center or chiral axis with saturated bonds,resulting in chiral conjugated helices(CCHs).CMCIs have garnered significant attention due to their flexible synthesis(annulativeπ-extension strategies),tailor-made structures(chiral polycyclicπ-conjugated frameworks),and diverse properties(optical,electronic,magnetic,and biochemical characteristics related to chirality).Furthermore,CMCI systems exhibit unique chiroptical properties,including circular dichroism(CD)and circularly polarized luminescence(CPL),which have elevated them as emerging stars among chiral organic functional molecules.Benefiting from their large conjugation planes and excellent electron-withdrawing ability,CMCIs often display outstanding electron mobility,high electron affinity,and strong light absorption or emission capabilities,making them valuable in various organic semiconductor applications.Their unique chiroptical properties and excellent semiconducting abilities position CMCIs as key players in the emerging field of chiral optoelectronics.Additionally,the appropriate packing modes and efficient charge transfer in solid-state CCHs provide excellent platforms for applications in chiral-induced spin selectivity(CISS)and topological quantum properties.In this Account,we present a comprehensive overview of three representative types of CMCIs:single-strand CCHs(ss-CCHs),double-strand CCHs(ds-CCHs),and multiple-strand CCHs(ms-CCHs).We focus on their rational design strategies,fundamental chiroptical properties,and chiral optoelectronic applications,particularly in circularly polarized organic photodetectors(CP-OPDs).We also discuss key parameters for evaluating chiroptical performance,such as the luminescence dissymmetry factor(glum)and photoluminescence quantum yield(ΦPL),and explore how the magnetic transition dipole moment(m),together with the electric transition dipole moment(μ),influence glum andΦPL.Through this review,we highlight successful strategies to enhance chiroptical responses,such as improvements in molecular symmetry,heteroannulation,and the introduction of multiple chiral centers.We also delve into the intrinsic correlation between chiral structure and excited-state parameters,supported by theoretical calculations.By emphasizing the judicious structure evolution of high-efficiency circularly polarized photoluminescence(CPPL)in solutions based on these CCHs,we offer perspectives on the future development of circularly polarized electroluminescence(CPEL)emitters and their potential applications in circularly polarized organic light-emitting diodes(CP-OLEDs),which would be more practical for future displays and photonic technologies.Finally,we emphasize the promising prospects of CCHs in multi-functional spin-polarized optoelectronic devices,aiming to achieve room-temperature,long-distance spin transport by leveraging the unique chiral-induced spin selectivity(CISS)effect and outstanding optoelectrical performance.
基金financially supported by the National Key R&D Program of China(No.2021YFA1502100)the National Natural Science Foundation of China(Nos.22472029,22172029,22311540011)+1 种基金the Natural Science Foundation of the Fujian Province(No.2024J010014)111 Project(No.D16008)。
文摘Poly(heptazine imide)(PHI),a new allotrope of heptazine-based carbon nitride,is usually synthesized in the presence of binary molten salts(e.g.,LiCl/NaCl,LiCl/KCl,NaCl/KCl)with diverse melting points and solvation abilities.However,the quantum efficiency of PHI for photocatalytic hydrogen production is still extremely restrained.Herein,a series of ternary molten salt mixtures(LiCl/NaCl/KCl)with varying compositions and properties,were employed for the rational control of the polymerization process of PHI and thus optimization in the optical properties,charge separation behaviors,and also photocatalytic performance.The results indicate that the ternary molten salts provide suitable environment for the development of a nanorod morphology,which significantly improves separation of photo-induced charge carriers.Hence,the optimized PHI presents a high apparent quantum yield(AQY=52.9%)for visible-light driven hydrogen production.
基金Financial support from Tongji University(20123231)is gratefully acknowledged.
文摘A new protocol for the synthesis of imides has been developed. In the presence of copper catalyst, N-benzylamideswere oxidized to the corresponding imides by TBHP/TEMPO system in moderate to good yields.
文摘Bis[（perfluoroalkyl）sulfonyl]imides [HN（SO2Rf）2, and Rf represents the perfluorinated alkyl group] supported on MCM-41 were synthesized and characterized by XRD, FTIR, SEM, TGA and N2-adsorption techniques. The supported catalysts, HN（SO2Rf）2/MCM-41, were used as the catalysts for the tert-butylafion of hydroquinone （HQ） with tert-butyl alcohol （TBA） in the liquid phase. A high yield （52.0%） of 2-tert-butyl hydroquinone （TBHQ） could be obtained in the presence of 5 tool% HN（SO2C4F9）2/MCM-41 under the optimized reaction conditions and the heterogeneous catalyst could be recycled at least 6 times without substantial loss of activity.
文摘2-substituted-1-amino-o-carboranes 2-R-1-NH_(2)-o-C_(2)B_(10)H_(10)(R=CH_(3),1a;R=Ph,1b)were synthesized and the reactions of these compounds with the yttrium dialkyl complex[Y(L)(CH_(2)SiMe3)_(2)](L=[2-(2,5-Me_(2)C_(4)H_(2)N)C_(6)H4NC(Ph)=NDipp]-,Dipp=2,6-iPr_(2)C_(6)H_(3))were investigated.The 1H NMR spectroscopy indicate that the reaction of ytrrium dialkyl complex with one equivalent of 2-R-1-NH_(2)-o-C_(2)B_(10)H_(10) produce the mixture of ytrrium alkyl-amido complex[Y(L)(2-R-1-NH-o-C_(2)B_(10)H_(10))(CH_(2)SiMe3)](R=CH_(3),2a;R=Ph,2b)and bis(amido)complex[Y(L)(2-R-1-NH-o-C_(2)B_(10)H_(10))_(2)](R=CH_(3),3a;R=Ph,3b).The yttrium bridging imido complex[Y(L)(2-CH_(3)-1-N-o-C_(2)B_(10)H_(10))]_(2)(4a)was obtained by heating the mixture at 55℃for 12 h.Complex 3a was isolated and characterized by treating the yttrium dialkyl complex with two equivalents of 1a.The structures of complexes 3a and 4a were verified by single-crystal Xray diffraction.CCDC:2424136,3a;2424137,4a.
基金the National Natural Science Foundation of China(No.21672147)Shanghai University of Traditional Chinese Medicine for financial support。
文摘Glycosyl imidates are among the pioneering donors for catalytic glycosylation.We report a new generation of imidates featuring the presence of a pentafluorophenyl group,introduced via substitution on imidoyl fluoride which is easily prepared,stable and user-friendly.The resulting donors exhibit exceptional shelf stability while can be readily activated to achieve high-yielding glycosylation,encompassing comprehensively aldosyl,ketosyl and ulosonyl donors,and both O-and N-glycosylation acceptors.Notably,the reactivity gradient across different generations of imidates,coupled with the accessible imidate acceptor from selective reaction of imidoyl fluoride at the anomeric hydroxyl group,enables a fully catalytic one-pot synthesis of oligosaccharides.
文摘The major challenge in photocatalytic water splitting lies in water oxidation reactions,which still suffer from poor charge separation.This study overcame inefficient charge separation by establishing a robust interfacial electric field through the electrostatic-driven assembly of Co_(3)O_(4) nanoparticles with a perylene imide supramolecule(PDINH).The well-aligned band structures and intimate interfacial contact in the PDINH/Co_(3)O_(4) heterostructure create an enhanced interfacial electric field that is 4.1-and 53.2-fold stronger than those of individual PDINH and Co_(3)O_(4),thus promoting directional charge separation and transfer.Moreover,S-scheme charge transfer strongly preserves the oxidative holes in PDINH to drive efficient water oxidation reactions.Consequently,PDINH/Co_(3)O_(4) composite achieves a photocatalytic oxygen evolution rate of 29.26 mmol g^(–1) h^(–1) under visible light irradiation,8.2-fold improvement over pristine PDINH,with an apparent quantum yield of 6.66%at 420 nm.This study provides fundamental insights into interfacial electric field control for the development of high-performance organic photocatalysts for efficient water oxidation.
文摘N-Methyl-N-propylpiperidiniumbis（trifluoromethanesulfonyl）imide （PP13TFSI）, bis（triflu- oromethanesulfonyl）imide lithium salt （LiTFSI）, and poly（vinylidene difluoride-co- hexafluoropropylene） （P（VdF-HFP）） were mixed and made into ionic liquid gel polymer electrolytes （ILGPEs） by solution casting. The morphology of ILGPEs was observed by scanning electron microscopy. It was found that the ILGPE had a loosened structure with liquid phase uniformly distributed. The ionic conductivity, lithium ion transference num- bet and electrochemical window were measured by electrochemical impedance spectroscopy, chronoamperometric and linear sweep voltammetry. The ionic conductivity and lithium ion transference number of this ILGPE reached 0.79 mS/cm and 0.71 at room temperature, and the electrochemical window was 0 to 5.1 V vs. Li＋/Li. Battery tests indicated that the ILGPE is stable when being operated in Li/LiFePO4 batteries. The discharge capacity maintained at about 135, 117, and 100 mAh/g at 30, 75, and 150 mA/g rates, respectively. The capacity retentions were almost 100% after 100 cycles without little capacity fading.
基金financially supported by National Basic Research Program of China(No.2014CB643604)
文摘The thermal and mechanical properties of the chemically imidized polyimide(CIPI) films and thermally imidized polyimide(TIPI) films were investigated systematically. Experimental results indicated that the CIPI films show dramatically enhanced tensile strength and modulus with obviously reduced coefficient of thermal expansion(CTE) in comparison with TIPI films. These enhancements results from the high in-plane orientation and close packing of the CIPI backbones. Compared with thermal imidization which starts at about 140 °C, the chemical imidization activated by acetic anhydride and isoquinoline initiates the cyclization even at room temperature.The resulting imide rings restrict the mobility of polymer chains and lead to the in-plane orientation with solvent evaporation.Additionally, fewer small molecules remain in the films after treated at 120 °C by chemical imidization than by thermal imidization. The polymer chain plasticization caused by the evaporation of small molecules at high temperature is obviously restricted. Moreover, the partially imidized polymer inhibits the decomposition of mainchains that occurs at subsequent high temperature process, being beneficial to the formation of high molecular weight PI films. Hence, chemical imidization pathway shows apparent advantage to produce PI films with great combined properties, including high modulus, strength and toughness, as well as high thermal dimension stability etc.
基金the National Natural Science Foundation of China(Nos.52077207,51822706,51777200 and 51772127)Beijing Natural Science Foundation(No.JQ19012)Dalian National Laboratory for Clean Energy Cooperation Fund,the CAS(No.DNL201912)。
文摘Nowadays,lithium-ion capacitors(LICs) have become a type of important electrochemical energy storage devices due to their high power and long cycle life characteristics with fast response time.As one of the essential components of LICs,the electrolytes not only provide the anions and cations required during charge and discharge processes,but also supply the liquid environment for ions to migrate between anodes and cathodes in LIC cells.It is well accepted that propylene carbonate(PC) cannot be used as a single solvent for Li-ion electrolyte due to the failure to form stable SEI film on graphite surface.In this work,the compatibility of PC-based electrolyte with commercial soft carbon anode and activated carbon cathode has been validated by using the laminated pouch LIC cells.The effects of additives on the electrochemical properties of PC-based LICs have been systematically investigated.Ethylene sulfite(ES) was proved to be an effective additive to promote capacity retention at high C-rate,which is superior to vinylene carbonate and fluoroethylene carbonate.The addition of 5 wt% ES plays an important role in reducing internal resistance,as well as improving electrochemical stability and low-temperature performances.This study is expected to be beneficial to explore robust electrolyte/additive combinations for LICs to reduce the internal resistance and to improve the lowtemperature performances.
基金financial supports from the Project of the National Natural Science Foundation of China(Grant Nos.21633011and 21872137)“Transformational Technologies for Clean Energy and Demonstration”+2 种基金Strategic Priority Research Program of the Chinese Academy of Sciences(Grant No.XDA21000000)Youth Innovation Promotion Association CAS(No.2018213)the Shanghai Synchrotron Radiation Facility(SSRF)for providing the beam time。
文摘Development of active and non-noble metal-based catalyst for H2 production via NH3 decomposition is crucial for the implementation of NH3 as a H2 carrier.Co-based catalysts have received increasing attention because of its high intrinsic activity and moderate cost.In this work,we examined the effect of BaNH,CaNH and Mg3 N2 on the catalytic activity of Co in the NH3 decomposition reaction.The H2 formation rate ranks the order as Co-BaNH>Co-CaNH>Co-Mg3 N2≈Co/CNTs within a reaction temperature range of 300-550℃.It is worth pointing out that the H2 formation rate of Co-BaNH at 500℃reaches20 mmolH2 gcat-1 min-1,which is comparable to those of the active Ru/Al2 O3(ca.17 mmolH2 gcat-1 min1)and Ru/AC(21 mmolH2 gcat-1 min-1)catalysts under the similar reaction conditions.In-depth research shows that Co-BaNH exhibits an obviously higher intrinsic activity and much lower Ea(46.2 kJ mol-1)than other Co-based catalysts,suggesting that BaNH may play a different role from CaNH,Mg3 N2 and CNTs during the catalytic process.Combined results of XRD,Ar-TPD and XAS show that a[Co-N-Ba]-like intermediate species is likely formed at the interface of Co metal and BaNH,which may lead to a more energy-efficient reaction pathway than that of neat Co metal for NH3 decomposition.
基金financially supported by the National 863 Program(No.2007AA03Z226)the National Key Program for Basic Research of China(No.2002CB211800 and 2009CB220100).
文摘Composite polymer electrolytes based on mixing soft-segment waterborne polyurethane （WPU） and 1-butyl-3-methylimidazolium bis[（trifluoromethyl）sulfonyl]imide （BMImTFSI） have been prepared and characterized. The addition of BMImTFSI results in an increase of the ionic conductivity. At high BMImTFSI concentration （BMImTFSI/WPU = 3 in weight ratio）, the ionic conductivity reaches 4.27 × 10^-3 S/cm at 30 ℃. These composite polymer electrolytes exhibit good thermal and electrochemical stability, which are high enough to be applied in lithium batteries.
基金financially supported by the National Basic Research Program of China(No.2014CB643603)the National Natural Science Foundation of China(No.51173178)
文摘In this study, polyimide fibers at different stages of imidization were characterized by TGA, DSC, and FTIR. The imidization degree （ID） calculated by TGA was based on the weight loss of each sample, which was caused by the imidization of residual amic acid groups. The results of TGA showed good regularity with the thermal treatment temperature of the PI fibers. For DSC, the ID was calculated based on the area of endothermal peak of each sample. Compared with TGA, DSC showed a relatively higher value because the endothermal peak was reduced by the exothermic re-formation of polyamic acid which may be partially degraded during thermal treatment. The IDs obtained by the FTIR spectra generally showed poorer regularities than those obtained by both TGA and DSC, especially for the results calculated using the 730 cm^-1 band. Based on the 1350 cm^-1 band, the obtained IDs showed better agreement with the TGA or DSC results. The results obtained by these three methods were compared and analyzed. The ID obtained by TGA showed much more reliability among these three methods.
文摘A series of novel aromatic poly ( amide imide)s containing phthalazinone moieties were prepared from 2-(4-aminophenyl)-4-[3-methyl-4-(4-aminophenoxy)-2,3-phthalazinone-1], a novel diamine 1 with four diimide-dicarboxylic acids by Yamazaki phosphorylation method with the inherent viscosity of 0.36~0.65 dL/g. These polymers had high glass transition temperatures above 300C and they lost 10% weight between 426~475C in N2. The structure of diamine 1 and the polymers was confirmed by IR, 1H NMR and MS. The obtained polymers were readily soluble in polar solvents such as NMP, m-cresol etc. and easily cast into tough, flexible films. The X-ray indicated that they are all amorphous.
