JOURNAL OF PHYSICAL CHEMISTRY B
·
2023
·
IF 3.3
Zhuanfang Jing,Yongquan Zhou,Toshio Yamaguchi,Koji Ohara,Jianming Pan,Guangguo Wang,Fayan Zhu,Hongyan Liu
The underlying recognition mechanisms of alkali metal ions by crown ethers in aqueous solutions are yet to be fully understood at the molecular level. We report direct experimental and theoretical evidence for the structure and recognition sequence of alkali metal ions (Li+, Na+, K+, Rb+, and Cs+) by 18-crown-6 in aqueous solutions by wide-angle X-ray scattering combined with an empirical potential structure refinement modeling and ab initio molecular dynamics simulation. Li+, Na+, and K+ are located in the negative potential cavity of 18-crown-6, with Li+ and Na+ deviating from the centroid of 18-crown-6 by 0.95 and 0.35 Å, respectively. Rb+ and Cs+ lie outside the 18-crown-6 ring and deviate from the centroid of 18-crown-6 by 0.05 and 1.35 Å, respectively. The formation of the 18-crown-6/alkali metal ion complexes is dominated by electrostatic attraction between the cations and the oxygen atoms (Oc) of 18-crown-6. Li+, Na+, K+, and Rb+ form the H2O···18-crown-6/cation···H2O “sandwich” hydrates, while water molecules only hydrate with Cs+ of the 18-crown-6/Cs+ complex on the same side of Cs+. Based on the local structure, the recognition sequence of 18-crown-6 for alkali metal ions in an aqueous solution follows K+ > Rb+ >Na+ >Li+, which is completely different from that (Li+ > Na+ > K+ > Rb+ > Cs+) in the gas phase, confirming that the solvation medium seriously affects the cation recognition of crown ethers. This work provides atomic insights into understanding the host–guest recognition and solvation behavior of crown ether/cation complexes.
研究领域:
化学
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物理化学
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DOI
PubMed
高影响因子
JOURNAL OF CHROMATOGRAPHY A
·
2018
·
IF 3.716
Shengqian Zhou,Jing Lin,Xiaofei Qin,Ying Chen,Congrui Deng
An improved ion chromatographic method including two elution procedures was proposed for the quantitative determination of atmospheric alkylamines in field atmospheric samples involving high levels of inorganic cations by using 18-crown-6 as mobile phase additive. When 18-crown-6 was added to the mobile phase, the retention times increased significantly for Na + , NH 4 + , K + and primary alkylamines but decreased for secondary and tertiary alkylamines due to the complexation with certain cations and interaction with both stationary and mobile phases of 18-crown-6. As a result, the separation of the cations was greatly promoted, which reduced the interference of peak distortion of overloaded inorganic cations on the quantitation of adjacent alkylamines. By using the presented method, five inorganic cations (Na + , NH 4 + , K + , Mg 2+ , Ca 2+ ) and six alkylamines (dimethylamine (DMAH + ), trimethylamine + diethylamine (TMAH + + DEAH + ), propylamine (MPAH + ), triethylamine (TEAH + ), ethanolamine (MEOAH + ) and triethanolamine (TEOAH + )) were effectively separated and determined, and the relative standard derivations (RSDs) of objective cations were all less than 1% for retention time and 3.1% for peak area (n = 9), respectively. The linearity was excellent for each cation (R 2 > 0.993) except for NH 4 + and TEOAH + showing a non-linear response (R 2 > 0.998 for theoretical non-linear fitting), and the detection limit of these cations were 0.03–1.19 ng. The proposed method was successfully used in the determination of both alkylamines and inorganic cations in ambient particulate matters and gaseous alkylamines in ceiling duct exhaust. The annual average concentrations of DMAH + , TMAH + + DEAH + and TEAH + were 15.56, 4.35 and 16.00 ng m −3 in PM 2.5 over Shanghai in 2013. The concentrations of gaseous DMA and TMA + DEA in ceiling duct exhaust reached a maximum of 940.0 and 112.7 μg m −3 , and were positively correlated with the human activity intensity, suggesting that human excreta emissions was a potential important source of atmospheric alkylamines in urban area of Shanghai.
研究领域:
环境科学
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分析化学
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DOI
PubMed
高影响因子
ZEITSCHRIFT FUR ANORGANISCHE UND ALLGEMEINE CHEMIE
·
2025
·Vol. 651
·期 3
·e202400210
·
IF 1.1
Ziyue Zhang,Zhuoer Cai,Yinan Zhang,Jian Chen,Xiu-Ni Hua,Baiwang Sun
The focus of this study is on the development of novel host–guest inclusion compounds, which is a crucial molecule model for the synthesis of dielectric phase transition materials. In this research, a new host–guest inclusion compound is successfully synthesized by selecting 18-crown-6 as the host and 3-aminocyclobutanone as the guest molecule. The thermal behavior and crystal structure of the compound are analyzed in this article. It is found that the compound exhibits a reversible phase transition near 147 K, accompanied by a dielectric anomaly, exhibiting dielectric switching characteristics. The 18-crown-6 molecule and the 3-aminocyclobutanone molecule are connected via hydrogen bonding. Furthermore, the enthalpy changes of the heating process and cooling process are also calculated. This finding is expected to yield valuable new insights into the design of host–guest inclusions.
研究领域:
材料化学
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物理化学
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高影响因子
JOURNAL OF MOLECULAR LIQUIDS
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2022
·
IF 6.633
Zhuanfang Jing,Yongquan Zhou,Wenqian Zhang,Toshio Yamaguchi,Koji Yoshida,Guangguo Wang,Li Han
Wide angle X-ray scattering (WAXS) and density functional theory (DFT) were employed to study the structures of aqueous 18-crown-6/CsCl solutions with CsCl concentrations of 0.25, 0.50 and 1.00 mol·L -1 . The empirical potential structure refinement (EPSR) modelling was adopted to get the pair distribution functions (PDFs), coordination numbers ( CN ), coordination number distributions (CND), angle distribution functions (ADFs), independent gradient model (IGM) and spatial density functions (SDFs) for the 18-crown-6 hydration, the complexation of 18-crown-6 and Cs + , the hydration of 18-crown-6/Cs + complex, and the association of Cl - and 18-crown-6/Cs + complex. Judging from the distance and orientation of water molecules, and the IGM between 18-crown-6 and water molecules, the oxygen atoms of 18-crown-6 (Oc) and the hydrogen atoms of water molecules (Hw) form strong hydrogen bonds, and these water molecules were distributed on both sides of the 18-crown-6 ring plane. However, the hydrogen atoms of 18-crown-6 (Hc) hardly form hydrogen bonds with the oxygen atoms of water molecules (Ow). Cs + is located directly above the 18-crown-6 ring plane of 0.35 to 2.05 Å away from the centroid of 18-crown-6, and forms 18-crown-6/Cs + complex with six Oc at r Cs + - O c = 3.06 Å. When the concentrations of CsCl are 0.25, 0.50 and 1.00 mol·L -1 , the complexation percentage of 18-crown-6 to Cs + are about 100%, 58% and 54%, respectively. No classic 2:1 “sandwich” 18-crown-6/Cs + complex structure was found in the solutions we surveyed. Both interaction energies and solvation stability energies reveal that the hydrates of 18-crown-6/Cs + complexes were formed in aqueous solutions. Cs + uncomplexed with 18-crown-6 hydrates with eight water molecules in aqueous solution, while Cs + can also hydrate with about four water molecules when it complexes with 18-crown-6. The results of atomic pair distances, the dipole distance of water molecules, the SDF and the IGM indicate that although water molecules can be located on both sides of the 18-crown-6 ring plane when the hydrates are formed, they hydrate with Cs + on the side where Cs + only existed. Cs + of 18-crown-6/Cs + complex associates with Cl - with the r Cs + - Cl - = 3.79 Å by electrostatic attraction.
研究领域:
化学
·
物理化学
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DOI
高影响因子
CHINESE JOURNAL OF ANALYTICAL CHEMISTRY
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2018
·
IF 0.824
Ruo-Fei WU,Yan-Dong HUANG,Yan-Qiu CHU,Zhi-Pan LIU,Chuan-Fan DING
The non-covalent interactions between 18-Crown-6 (18c6) and 20 common types of protonated amino acids were explored by electrospray ionization mass spectrometry. The mass spectra showed that 18c6 could react with amino acids to form a non-covalent complexe in a stoichiometric ratio of 1:1. The calibration curves and linear equations for the complexes of L -Phe, L -Tyr, L -Lys and L -Asp with 18c6 were established by mass spectrometric titration and used as reference values for competitive ESI-MS. Through competitive equilibria, the binding constants for the complexes of 18c6 with other L -amino acids and their D -isomers were derived. It was found that, as a general trend, lg K a for the complexes of 18c6 with the basic amino acid and the amino acid with alkyl side chain were larger than other complexes, and among the amino acid with alkyl side chain, Gly and Ala exhibited greater 18c6 binding affinities. As for Ser and Thr, the intramolecular hydrogen bond between the nitrogen atom from terminal –NH 2 and the oxygen atom from carboxyl might impede their protonated amino-group to attack the 18c6. Furthermore, Gln and Asn exhibited lower binding affinities to 18c6, probably due to effects of electron-withdrawing group of acylamide. Finally, the chiral selectivity of 18c6 for L -amino or D -amino acids were measured by ESI-MS, and the result showed that 18c6 could only recognize some neutral amino acid isomers.
研究领域:
分析化学
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生物化学
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DOI
高影响因子
ADSORPTION-JOURNAL OF THE INTERNATIONAL ADSORPTION SOCIETY
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2024
·
IF 3
Ma Licheng,Qi Jungang,Gao Leqi,Wei Tao,Guo Yanhua
In this study, a cesium ion imprinted polymer (Cs(I)-IIP) was prepared by free radical thermal polymerization using 18-crown-6-ether (18C6) as ligand, methacrylic acid (MAA) as functional monomer, and ethylene glycol dimethacrylate (EGDMA) as crosslinking agent, which can be used for adsorption and separation of cesium ions from low-concentration solutions. The adsorption kinetic and isotherm results showed that the adsorption of Cs + fitted to the pseudo-second-order kinetic model and Langmuir model, indicating that the adsorption of Cs + on Cs(I)-IIP was the monolayer chemical adsorption. The maximum adsorption capacity was 84.21 mg·g − 1 . The selective adsorption properties are performed in Cs + , Li + , Na + , and K + multicomponent systems. The results showed that the Cs(I)-IIP has a high selectivity in the presence of coexisting Li + , Na + , and K + , and the selectivity coefficients ( K’ ) of Cs(I)-IIP for Cs + /Li + , Cs + /Na + , Cs + /K + are 2.1, 1.56, and 1.33, respectively. The high adsorption capacity and selectivity are attributed to the introduction of imprinting technology to form specific Cs + recognition adsorption sites, and the 18C6 cavity was easier to recognize Cs + in the competitive adsorption process. Finally, the Cs(I)-IIP can be regenerated and reused for 10 times with the adsorption capacity only decreased by 8.1%, indicating that the polymer has good reuse performance.
研究领域:
材料科学
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环境科学
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DOI
高影响因子
APPLIED ORGANOMETALLIC CHEMISTRY
·
2012
·Vol. 26
·期 9
·478-482
·
IF 2.061
Wenyi Chu,Xinmin Li,Yanjun Hou,Hua Wang,Hongyu Li,Xiaobin Yuan,Zhizhong Sun
Pd/C-catalyzed Suzuki–Miyaura cross-coupling between aryl bromides and arylboronic acids in 50% methanol aqueous solution proceeded smoothly in the presence of 18-crown-6. Various aryl bromides bearing electron-withdrawing groups and electron-donating groups coupled with arylboronic acid in high yields. In addition, the catalyst could be recycled five times without loss of activity. Copyright © 2012 John Wiley & Sons, Ltd.
研究领域:
有机化学
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催化化学
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DOI
高影响因子
Particuology
·
2022
·
IF 3.251
Fang Wang,Zhuang Liu,Rui Xie,Xiao-Jie Ju,Wei Wang,Da-Wei Pan,Liang-Yin Chu
Lead(II) (Pb 2+ ) ions are toxic heavy metal ions that can accumulate in the human body through water and cause severe health problems, including neurotoxicity, nephrotoxicity, hematological toxicity and even genotoxicity effects. To remove Pb 2+ selectively and effectively from aqueous solutions, we develop a novel type of Pb 2+ -recognizable microgels with excellent adsorption capacity to Pb 2+ , which are fabricated from 4-acrylamidobenzo-18-crown-6 (B18C6Am) and N -isopropylmethacrylamide (NIPMAM) monomers by precipitation copolymerization method. The prepared poly( N -isopropylmethacrylamide- co -4-acrylamidobenzo-18-crown-6) (PNMB) microgels exhibit expanded structures, because the electron-donating methyl groups at α-carbon could descend the polarity of C O in the NIPMAM monomers and thus weaken the polymer segment···segment interactions. The expanded structures of PNMB microgels are beneficial for adsorption of Pb 2+ due to the low steric hindrance in the polymeric networks. The Pb 2+ adsorption isotherms of PNMB microgels are consistent with the Langmuir model for monolayer adsorption. The results indicate that the prepared Pb 2+ -recognizable PNMB microgels are highly promising for the selective removal of lead(II) ions from aqueous solutions.
研究领域:
材料科学
·
环境科学
·
化学
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DOI
高影响因子
ADVANCED FUNCTIONAL MATERIALS
·
2023
·Vol. 33
·期 27
·2215109
·
IF 19
Yanran Zhu,Qian Chen,Yue Zhou,Xingya Li,Liang Ge,Tongwen Xu
Acid recycling via cation exchange membranes (CEMs) has attracted considerable attention from traditional industries and advanced manufacturing because of the economic and environmental advantages. However, current polymeric CEMs merely have constant ion channels by the fixed groups in the matrix and lack the synergy of bi-functional sites. Herein, a series of dibenzo-18-crown-6 (DB18C6) functionalized sulfonated poly(biphenyl alkylene) membranes is reported. The resultant membranes form phase separation and ordered ion channels by the electrostatic interaction between DB18C6-H + complexes and the SO 3 − anionic sites, constructing a low-swelling synergistic hydrophilic network. The prepared membranes have high proton permeation rates of 2.98-4.85 mol m −2 h -1 and extremely low ferrous ion permeabilities, leading to a high H + /Fe 2+ selectivity of ≈3153 at the current density of 10 mA cm -2 , which is one order of magnitude higher than the commercial and previously reported membranes via the electrodialysis. These results provide strategies for designing bi-functional ion exchange membranes for selective ion transport via utilizing crown ether/cation complexes.
研究领域:
材料科学
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化学工程
·
环境科学
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产品关联
DOI
高影响因子
Journal of Physical Chemistry C
·
2020
·
IF 4.189
Jun Xu,Sai Li,Chaochao Qin,Zongjing Feng,Yaping Du
As illumination is a fundamental human need, the exploration of illumination sources possessing high efficiency and broadband white-light emission is highly desirable. Zero-dimensional (0D) metal halide compounds are promising candidates, and some lead-free antimony-containing compounds exhibit bimodal white-light emissions. However, their origins are still unclear. To solve this issue, we designed and prepared a new family of 0D metal halide compounds consisting of [M(18-crown-6)]+ (M = NH4, Rb) and SbX52– (X = Cl, Br) units. We found that the emission profiles of 0D compounds are distinct to and well separated from that of 18-crown-6 ether, excluding the intraligand charge transfer mechanism proposed in several reports. Femtosecond transient absorption data and the compositional dependence of photophysical properties imply that bimodal white-light emission is induced by both singlet state and triplet state of the self-trapped excitons (1STE and 3STE) coupled to metal halides. These 0D compounds are also very efficient emitters, with a white-light photoluminescence quantum yield as high as 54%.
研究领域:
材料科学
·
光电
·
光子学
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产品关联
DOI
高影响因子
Sustainable Energy & Fuels
·
2025
·
IF 4.1
Bo zhang,Liguang Qin,Jiaqing Tang,Minghe Zhu,Yunzeng Cui,Shiyu Hua,Qinyang Xue,Shangqi Sun,Chang Guo
Lithium metal is considered the top choice for anode materials due to its exceptionally high energy density (3860 mAh g-1). However, its practical use in lithium metal anodes (LMAs) is limited by significant dendrite growth and unstable interface between the anode and electrolyte. Herein, 18-crown-6 and fluoroethylene carbonate (FEC) were introduced as combined additives to improve the stability of the electrode/electrolyte interface and enhance long-term cycling performance. The presence of FEC promotes the formation of a LiF-rich solid electrolyte interphase (SEI), which guides lithium deposition and accelerates the transport of Li+ ions. Additionally, 18-crown-6 can eliminate “hotspots” during the lithium deposition and dissolution processes, leading to superior electrochemical performance. By incorporating 1wt% 18-crown-6 and 10vol% FEC, Li||Cu half-cells achieved an impressive average coulombic efficiency of 97%, while Li||Li symmetric cells demonstrated excellent stability for over 800 hours. When paired with LiFePO4, the Li||LFP full cell retained approximately 98% of its capacity and maintained a high average coulombic efficiency of 99% after 100 cycles at 0.5 C. This research underscores the vital role of 18-crown-6 and FEC in electrolytes, revealing a fresh strategy to reduce lithium dendrite formation in lithium-based energy storage systems.
研究领域:
电化学
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储能
·
材料科学
·
电池技术
·
表面工程
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产品关联
DOI
高影响因子
ADVANCED MATERIALS
·
2025
·
IF 26.8
Wenji Zhan,Haifei Wang,Jiahao Guo,Yugang Liang,Yanming Wang,Jixin Wu,Zhengzheng Dang,Ni Zhang,Jingjing Cao,Yingping Fan,Yu Zou,Bowei Li,Yao Wang,Yuetian Chen,Yanfeng Miao,Yixin Zhao
Deep-red light-emitting diodes (LEDs) with 690−710 nm emission show high significance in optical, agricultural, and biomedical applications. As primary candidates for deep-red emitters, all-inorganic CsPbI 3 films suffer from fused large grains with abundant trap states, leading to inferior performance of deep-red perovskite LEDs (PeLEDs). Here we report CsPbI 3 nanocrystal films with strong space confinement and notable performance at ∼700 nm of deep-red emission via bulk fabrication. The dual roles of diaza-18-crown-6 dihydriodide additive as crystallization regulator and Lewis base ligand trigger more nucleation sites, retarded grain growth and passivated trap states, ensuring the crystallization of high-quality space-confined CsPbI 3 nanocrystal films. This approach establishes a record-high external quantum efficiency (EQE) of 23.4% for deep-red PeLEDs, and achieves a maximum luminance of 10152 cd m −2 . Low roll-off is also demonstrated that EQE maintain over 20% under a high current density of 900 mA cm −2 , which is superior to state-of-the-art deep-red organic and quantum-dot LEDs. The T 50 operating lifetime is estimated to be 234 h at an initial radiance of 6.3 W sr −1 m −2 . This work provides an effectual strategy to accelerate radiative recombination and enhance the performance of CsPbI 3 -based deep-red PeLEDs.
研究领域:
材料科学
·
光电子学
·
纳米技术
·
钙钛矿发光二极管
✓ 已验证
DOI
PubMed
高影响因子
危险品化学品经营许可证（带存储）