POLYMER
·
2022
·
IF 4.432
Yongjiu Li,Yu Dai,Yue Gao,Dajie Zhang,Junwei Lv,Qian Yin,Xiangyang Liu,Longbo Luo
Herein, we introduce controllable one-pot polycondensation which can prepare block aromatic polyamide by regulating nucleophilicity of amino groups through reversible coordination interaction. Due to different coordination ability of diamine monomers with Cu 2+ , effect of Cu 2+ on its nucleophilicity is quite different and nucleophilicity is suppressed more significantly for the diamines with stronger coordination ability. Then, reactivity difference of diamine monomers owning different coordination ability can be magnified significantly through coordination interaction. When the two kinds of diamine monomers with different coordination ability exist in the reaction system, diamine monomer with weaker coordination ability reacts quickly with diacyl chloride in the initial phase of the reaction and forms corresponding chain segments. When the diamine monomer with weaker coordination ability is nearly depleted, the diamine monomer with stronger coordination ability begins to undergo uncoordinated reaction with Cu 2+ , restoring its reactivity with acyl chloride and forming corresponding chain segment in the second stage reaction.
研究领域:
材料科学
·
有机化学
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产品关联
DOI
高影响因子
Catalysis Science & Technology
·
2021
·Vol. 11
·期 19
·6498-6506
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IF 6.119
Shengxin Chen,Ran An,Yingwei Li,Yuting Zhu,XinBao Zhu,Ruixia Liu,Xingang Li
Although poly(ionic liquid)s (PILs) have received extensive attention and research, the strategy for designing efficient PILs catalysts remains a challenge. This work reports a series of efficient PILs catalysts with increasing ionic ratio and various anion species to regulate electrophilic/nucleophilic ability, and explores the effect of the ionic ratio on the coupling reaction of propylene oxide (PO) with CO2 or methanol. These PILs are synthesized by a quaternization reaction between poly(N-vinylimidazole) (PVIM) and dihaloalkanes, where the amount of crosslinker of dihaloalkanes controls the ionic ratio of PILs, further affecting their microcosmic environment, morphologies and properties. It is noteworthy that the ionic ratio with IL units and imidazoline group can work as a trigger and promoter in the coupling reaction of PO with CO2 or methanol. The ionic ratio could open the reaction compared with the parent PVIM and the choice of anion could turn the reaction on or off. It suggested that the active microstructure and electrophilic/nucleophilic ability of PILs could be regulated by the ionic ratio. In these active sites, the IL units-connected imidazoline group could weaken the interaction of the cation–anion, giving enhanced leaving ability of the anion, contributing to the excellent catalytic performance.
研究领域:
催化化学
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材料科学
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环境化学
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产品关联
DOI
高影响因子
Journal of Chemical Information and Modeling
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2024
·
IF 5.6
Xu Li,Haoliang Zhong,Haoyu Yang,Lin Li,Qingji Wang
Nucleophilic index (NNu) as a significant parameter plays a crucial role in screening of amine catalysts. Indeed, the quantity and variety of amines are extensive. However, only limited amines exhibit an NNu value exceeding 4.0 eV, rendering them potential nucleophiles in chemical reactions. To address this issue, we proposed a computational method to quickly identify amines with high NNu values by using Machine Learning (ML) and high-throughput Density Functional Theory (DFT) calculations. Our approach commenced by training ML models and the exploration of Molecular Fingerprint methods as well as the development of quantitative structure–activity relationship (QSAR) models for the well-known amines based on NNu values derived from DFT calculations. Utilizing explainable Shapley Additive Explanation plots, we were able to determine the five critical substructures that significantly impact the NNu values of amine. The aforementioned conclusion can be applied to produce and cultivate 4920 novel hypothetical amines with high NNu values. The QSAR models were employed to predict the NNu values of 259 well-known and 4920 hypothetical amines, resulting in the identification of five novel hypothetical amines with exceptional NNu values (>4.55 eV). The enhanced NNu values of these novel amines were validated by DFT calculations. One novel hypothetical amine, H1, exhibits an unprecedentedly high NNu value of 5.36 eV, surpassing the maximum value (5.35 eV) observed in well-established amines. Our research strategy efficiently accelerates the discovery of the high nucleophilicity of amines using ML predictions, as well as the DFT calculations.
研究领域:
化学信息学
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计算化学
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DOI
PubMed
高影响因子
ELECTROCHIMICA ACTA
·
2019
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IF 5.383
Di Wu,Weiqin Wang,Yanna NuLi,Jun Yang,Jiulin Wang
To enhance the electrochemical performance of Se cathode for high-energy-density magnesium-selenium (Mg–Se) batteries with easily prepared nucleophilic (PhMgCl) 2 -AlCl 3 +LiCl/THF (APC-based) hybrid electrolyte, Cu doped Se@MC composites (Cu–Se@MC) with different Cu content (0.05, 0.10, 0.15, 0.20, 0.25 and 0.30) are prepared by impregnation reduction and melting selenization method. The composites are composed of a mixture of chain-structured Se and CuSe embedding in the microporous carbon, and the addition of Cu significantly improves reversibility and cycle life of the composites in the nucleophilic APC-based hybrid electrolyte. At the 0.25 Cu content, the cell exhibits 346.7mAhg −1 first discharge capacity and the specific capacity maintains at 112mAhg −1 after 200 cycles at a current density of 50 mA g −1 , which is superior to that with non-nucleophilic Mg(HMDS) 2 -(AlCl 3 ) 2 –MgCl 2 +LiTFSI/DME (HMDS-based) and MBA-(MgCl 2 ) 2 –(AlCl 3 ) 2 +LiCl/THF (MBA-based) hybrid electrolytes.
研究领域:
材料科学
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电化学
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电池技术
✓ 已验证
DOI
高影响因子
Molecular Catalysis
·
2025
·
IF 4.9
Wen Liu,Qian Su,Zifeng Yang,Mengqian Fu,Yifan Liu,Weiguo Cheng
Abtract The conversion of CO₂ into cyclic carbonates is a feasible approach for CO 2 mitigation. The environmentally friendly halide-free catalysts, which could avoid the waste halide contamination and industrial equipment corrosion are highly concerned. In this study, a series of halide-free ionic liquids with dual regulation of anion basicity and nucleophilicity were designed to achieve high catalytic efficiency. Among the synthesized ionic liquids, the [BmmIm][PA] demonstrated superior catalytic efficiency, delivering 94.9 % product yield with 99.9 % selectivity under the optimized conditions (70 °C, 2 mol%, 3.5 h, 10 bar). According to the deep activation energies analysis, the superior catalytic efficiency of [BmmIm][PA] was attributed to the strong nucleophilicity of [PA] reducing the ring-opening activation energy and the mild basicity of [PA] reducing the ring-closing activation energy simultaneously. The lower reaction activation energy catalyzed by [BmmIm][PA] was further confirmed by kinetic experiments. Finally, by combining DFT calculations with IR, NMR spectroscopy, a detailed catalytic mechanism involving direct epoxides activation by [PA], CO 2 insertion and ring-closing was proposed. This work provided a more comprehensive understanding of halide-free catalysts and laid a theoretical foundation for the green and efficient conversion of CO 2 .
研究领域:
绿色化学
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催化化学
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环境科学
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有机合成
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物理化学
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分子催化
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二氧化碳利用
✓ 已验证
产品关联
DOI
高影响因子
ACS Applied Materials & Interfaces
·
2020
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IF 8.758
Dan Huang,Shuangshuang Tan,Maosheng Li,Dandan Wang,Chunhua Han,Qinyou An,Liqiang Mai
The application of high-energy Mg/S batteries was obstructed by the insufficiency of low-cost and non-nucleophilic electrolyte. In this work, a non-nucleophilic electrolyte was prepared by facilely dissolving Mg(CF3SO3)2, MgCl2, and AlCl3 in 1,2-dimethoxyethane (DME). The equilibrium species of the MTB electrolyte mainly comprise [Mg2(μ-Cl)2(DME)4]2+ and [(CF3SO3)AlCl3]−, which are generated by dehalodimerization reaction and Lewis acid–base reaction, respectively. The electrolyte exhibits a highly efficient reversible Mg deposition/dissolution, low overpotential of around 250 mV, and good oxidative stability up to 3.5 V after conditioning. The conditioning process that the active [Mg2(μ-Cl)2(DME)4]2+ species transforms into [Mg3(μ3-Cl)(μ2-Cl)2(DME)7]3+ was demonstrated, owing to the irreversible deposition of Al3+ on Mg foil. More importantly, this electrolyte exhibited good compatibility and kinetics for reversible Mg/MgSx redox, resulting in a high specific capacity of 866 mAh g–1 at 200 mA g–1 and high power density of 550 W kg–1. This work offers a new direction for low-cost, non-nucleophilic electrolyte and paves the way to explore high-power Mg/S batteries.
研究领域:
材料科学
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电化学
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能源存储
✓ 已验证
产品关联
DOI
PubMed
高影响因子
CHEMICAL ENGINEERING SCIENCE
·
2021
·
IF 4.311
Zifei Yan,Zeyu Ma,Jian Deng,Guangsheng Luo
The ring-opening reactions of epoxides with carboxylic acids have great applications in the coating and polymer industry. However, the systematical study on the structure-activity relation of catalysts is still scarce. In this work, the carboxylate catalysts were directly prepared rather than using the traditional catalysts like amines or quaternary ammonium salts, thus removing the induction period and making the kinetic results more accurate and rigorous. The reaction orders of reactants and catalyst were obtained by kinetic experiments, and based on that, the kinetic equation and mechanism were put forward. The influences of solvent environment, as well as the structure and properties of catalysts on their activity were further studied. It was found that the alkalinity of the carboxylate ions and the electrostatic interaction are the key factors to affect the nucleophilicity of catalysts. Generally, the nucleophilicity is enhanced with the increase of cation radius and anion branches.
研究领域:
有机化学
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催化
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高分子科学
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材料科学
✓ 已验证
DOI
高影响因子
Chemical Science
·
2025
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IF 7.4
Yuping Chen,Guoqing Bian,Zhikun Wu,Qing Tang
Ligand exchange is an important strategy to functionalize metal nanoclusters (NCs) for enhanced properties. Thiolates and alkynyls have been widely used for NC protection, however, the possibility for alkynyl-for-thiolate exchange as well as the kinetics for the ligand exchange process have remained largely unexplored. Herein, we reported the first kinetic investigation into the alkynyl-for-thiolate exchange through the reaction of thiolated Au25(SR)18 with the incoming alkynyl ligands. Interestingly, our simulations revealed the electronic and steric effect of alkynyl ligands, and the precursor cluster’s charge state collectively govern the exchange efficiency and regioselectivity. Notably, the alkynyl-for-thiolate exchange is highly facile when reacting with the nucleophilic lithium or gold(I)−alkynyl complex (Au(C≡CR) or Li(C≡CR)), but fails when using HC≡CR as the exchange ligand. The Au(C≡CPh) complex exhibits charge-state-dependent exchange at the S1 or S2 position, whereas the sterically bulky Au(C≡CtBu) complex decelerates the exchange kinetics and universally targets the S1 position as the exchange product. By contrast, the lithium-alkynyl complex (Li(C≡CPh) or Li(C≡CtBu)) preferentially leads to the S1' exchange isomer, driven by the ionic Li−C bonding that enhances the C≡C π*-electron density and alkynyl nucleophilicity. Our predictions are further validated by the ligand exchange experiments between phenyl ethanethiol (PET) protected [Au25(PET)18]− and Au(C≡CtBu). The electrospray ionization mass spectra (ESI-MS) unambiguously confirms the successful substitution of about 4, 5 and 6 PET ligands by the −C≡CtBu ligand, and the absorption spectrum is drastically changed upon the alkynyl exchange. This work establishes important atomic-level understanding of the alkynyl-for-thiolate exchange mechanism, offering a convenient strategy of realizing alkynyl and thiolate co-protected gold clusters under mild conditions.
研究领域:
纳米材料
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物理化学
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团簇科学
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材料化学
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表面化学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
GREEN CHEMISTRY
·
2023
·Vol. 25
·期 14
·5438-5448
·
IF 9.8
Shiqi Huang,Xianglei Meng,Yanzhao Gao,Minmin Liu,Junjie Zhang,Yu Zhou,Yuting Song,Yanyan Diao
According to the requirements of sustainable green development, the efficient green synthesis of fluorine chemical products is an inevitable trend. In this work, we used ionic liquids as an effective catalyst in an important fluorochemical reaction – hexafluoropropylene dimerization for the first time. The effects of ionic liquids with different spatial positions, substituents and nucleophilic anions on the catalytic performance of hexafluoropropylene dimerization were systematically studied. The results showed that the strong nucleophilic trisubstituted thiocyanate imidazole ionic liquid [C6mmim][SCN] had the highest activity under the optimum reaction conditions, the turnover frequency (TOF) was 108.36 h−1 and the selectivity was 97.96%. Compared with the traditional metal salt catalyst system, the catalytic activity of ionic liquids was double. In addition, based on the XPS analysis results and density functional theory (DFT), a possible reaction mechanism was proposed. The effective catalytic activity of ionic liquids was mainly attributed to the strong nucleophilicity of anions and the weak interaction between cations and anions. This work will successfully provide a green synthesis route for hexafluoropropylene dimerization and further promote the efficiency and greening of fluorine chemical reactions.
研究领域:
化学工程
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催化
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绿色化学
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氟化学
✓ 已验证
产品关联
DOI
高影响因子
ACS Applied Materials & Interfaces
·
2021
·
IF 9.229
Wen Ren,Di Wu,Yanna NuLi,Xuan Zhang,Jun Yang,Jiulin Wang
The electrolyte based on magnesium bis(diisopropyl)amide (MBA), a low-cost and non-nucleophilic organic magnesium salt, is proposed to be an admirable alternative for rechargeable magnesium batteries but suffers from limited ionic conductivity and an inferior electrochemical window in the commonly used ether solvents. In this work, the 1-butyl-1-methylpiperidinium bis(trifluoromethyl sulfonyl)imide (PP14TFSI) ionic liquid as the cosolvent of tetrahydrofuran (THF) in chlorine-free MBA-based electrolytes has been first demonstrated to remarkably improve the ionic conductivity and broaden the oxidative stable potential (2.2 V vs Mg/Mg2+) on stainless steel. Reversible Mg electrochemical plating/stripping with a low overpotential below 200 mV and ca. 90% Coulombic efficiency are obtained. The current density of Mg plating/stripping is increased 238 times after the addition of PP14TFSI, where the mechanism of competitive coordination of TFSI– making an easier Mg plating/stripping is proposed theoretically. The MBA-2AlF3 electrolyte with a ratio-optimized THF/PP14TFSI cosolvent exhibits good compatibility with the Mo6S8 cathode. Furthermore, the Se@pPAN|Mg full cell exhibits an initial capacity of 447.8 mAh g–1 and as low as ∼0.66% capacity decay per cycle for more than 70 cycles at 0.2 C with the synergy of LiTFSI additives. The facile modification strategy of ionic liquid in the MBA-based electrolyte sheds inspiring light on exploring non-nucleophilic and chlorine-free electrolytes for practical rechargeable magnesium batteries.
研究领域:
材料科学
·
电化学
·
储能技术
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电池技术
·
无机化学
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物理化学
✓ 已验证
DOI
高影响因子
WATER RESEARCH
·
2020
·
IF 9.13
Chen Zhong,He Zhao,Qingzhen Han,Hongbin Cao,Feng Duan,Junyi Shen,Yongbing Xie,Wanqian Guo,Shanshan Sun
As an important raw material and intermediate of widely used antibiotics cefazolin and cefazedone, 2-mecapto-5-methyl-1,3,4-thiadizaole (MMTD) in antibiotic wastewater is hardly decyclized during wastewater treatment, posing great risk to the environment. This work proposed a green “coupling-oxidation” process to enhance ring-opening of MMTD during antibiotic wastewater treatment. In particular, the significant role of humic substances (HS) as pre-coupling reagent was emphasized. Real HS and different model HS, especially quinones, not only efficiently pre-coupled MMTD (>95%) but also promoted the MMTD removal by MnO 2 (from 72.4% to 92.4%). Mass spectrometric analysis indicated that MMTD pre-coupled to HS would be oxidized with ring opening to environmental-friendly sulfonated HS, while direct oxidation of MMTD produced MMTD dimers or sulfonated MMTD that would not undergo ring opening. Theoretical calculations indicated that pre-coupling to HS enabled the ring-opening oxidation by increasing the nucleophilicity and decreasing ring-opening barrier of thiadiazole. Based on the density function theory (DFT), the global nucleophilicity index (Nu) followed the trend of HS-MMTD > MMTD dimer > sulfonated MMTD, while the ring-opening barrier followed the trend of HS-MMTD (274 kJ/mol) < first ring of MMTD dimers (286 kJ/mol) < MMTD (338 kJ/mol). Theoretical calculations further confirmed that the cross-coupled HS-MMTD intermediate was more likely to be decyclized than intermediates from direct oxidation. Moreover, nitrogen, acetaldehyde group, sulfate and CO 2 were the products of thiadiazole ring degradation. Pre-coupling of MMTD with HS provides a new idea and strategy in developing a green and sustainable scheme for wastewater treatment.
研究领域:
环境科学
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化学工程
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废水处理
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理论化学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
JOURNAL OF HAZARDOUS MATERIALS
·
2021
·
IF 10.588
Lei Xu,Yuting Wang,Erqun Song,Yang Song
Polybrominated diphenyl ethers (PBDEs) are a category of brominated flame retardants , which were widely used in industrial products since the 1970 s. Our previous studies indicated quinone-type metabolites of PBDEs (PBDE-Qs) cause neurotoxicity, however, their inherent toxicological mechanism remains unclear. Here, we first synthesized PBDE-Qs and corresponding reduced hydroquinone homologous (PBDE-HQs) with different pattern of bromine substitution. Their nucleophilic and redox properties were investigated. PBDE-Qs react with reduced glutathione (GSH) via Michael addition and bromine displacement reaction, whilst PBDE-HQs lack the ability of reacting with GSH. Of note, the displacement reaction only occurs with bromine on the quinone ring of PBDE-Qs but not phenyl ring. Next, electron paramagnetic resonance (EPR) analysis revealed the generation of SQ •− , along with their downstream hydroxyl radical (HO ) and methyl radical ( CH 3 ) through a PBDE quinone/semiquinone/hydroquinone (Q/SQ •− /HQ) futile cycle. In addition, a structure-dependent cytotoxicity pattern was found, the exposure of PBDE-Q/HQ with bromine substitution on the quinone ring resulted in higher level of apoptosis and autophagy in BV2 cells. In conclusion, this work clearly demonstrated that the nucleophilic and redox properties of PBDE-Qs/HQs are responsible for their neurotoxicity, and this finding provide better understanding of neurotoxicity of PBDEs.
研究领域:
环境科学
·
毒理学
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神经科学
·
化学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
危险品化学品经营许可证（带存储）