Scientific Reports
·
2018
·Vol. 8
·期 1
·1-11
·
IF 4.122
Tang Shanshan,Tsona Narcisse T.,Du Lin
In order to investigate ring-size effects on the stability and spectral shifts of hydrogen bonded cyclic ethers complexes, the strength of hydrogen bonds in gas phase complexes formed between 2,2,2-trifluoroethanol (TFE) and selected cyclic ethers were examined using FTIR spectroscopy. TFE was chosen as hydrogen bond donor in these complexes, while trimethylene oxide (TMO), tetrahydrofuran (THF) and tetrahydropyran (THP) were selected as hydrogen bond acceptors. Comparable OH-stretching red shifts were observed in the three kinds of complexes. The difference of red shifts is so small (<7 cm −1 ) for TFE−TMO/THF/THP complexes that one can conclude that their stabilities and the strength of the hydrogen bonds are nearly similar and do not show any marked dependence with the ring size of the hydrogen bond acceptor. The equilibrium constants for the complexation were determined, and atoms-in-molecules (AIM) and natural bond orbital (NBO) analyses were performed to further investigate the intermolecular interactions. Regardless of the ring size, hydrogen bonds in the complexes showed similar strength, in agreement with the observed OH-stretching red shifts.
研究领域:
化学
·
物理化学
✓ 已验证
DOI
PubMed
高影响因子
SPECTROCHIMICA ACTA PART A-MOLECULAR AND BIOMOLECULAR SPECTROSCOPY
·
2019
·
IF 2.931
Shanshan Tang,Lin Du
In order to explore the effect of methylation on the stability and spectral shift of hydrogen bond complexes, the complexes of 2,2,2-trifluoroethanol (TFE) with propylene oxide (PO) and isobutylene oxide (IBO) were investigated by Fourier transform infrared (FTIR) spectroscopy and ab initio computations. The comparable OH-stretching red shifts were observed upon complexation, and an enhancement of the OH-stretching band is shown with the partial pressure of monomers increasing. The OH-stretching frequency of TFE is red shifted by 180 and 201 cm −1 with PO and IBO, respectively. By using quantum chemical calculations , we predicted the geometric parameters, binding energies, and spectral shifts of TFE PO/IBO hydrogen bond complexes. The calculated and observed spectral shifts follow the same trends. Compared with the TFE ethylene oxide (EO) complex, the strength of the hydrogen bond in complex increases with the addition of methyl group , which likely results from the increase in basicity of the hydrogen bond acceptor. By combining the experimental integrated absorbance and the calculated IR intensity of the OH-stretching vibrational transition , the equilibrium constant for the complex formation was determined. In addition, atoms-in-molecules (AIM) and natural bond orbital (NBO) analyses were carried out to explain the red shift and the nature of the interaction in these complexes.
研究领域:
物理化学
·
分子光谱学
✓ 已验证
DOI
PubMed
高影响因子
CATALYSIS COMMUNICATIONS
·
2017
·
IF 3.33
Tingting Hou,Chaofeng Zhang,Yehong Wang,Zhenting Liu,Zhixin Zhang,Feng Wang
A metal-free and efficient approach to N -arylpyrrolidines from arylamines and cyclic ethers catalyzed by hydrogen iodine is described. In this protocol, no additive is added and a wide range of N -arylpyrrolidines are synthesized with up to 99% yield. Reaction mechanism involving iodine radical is proposed.
研究领域:
有机化学
·
催化
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF COLLOID AND INTERFACE SCIENCE
·
2024
·
IF 9.4
Jiahang Zou,Hanxu Yang,Shilin Wu,Zhengquan Xiao,Zhipeng Jiang,Wangqiang Shen,Yongtao Li
Ether-based electrolytes are known for their high stability with lithium metal anodes (LMAs), but they often exhibit poor high-voltage stability. Structural optimization of ether-based solvent molecules has been proven to effectively broaden the electrochemical window of these electrolytes, yet the optimization rules within cyclic ethers remain unclear. Herein, we investigate the impact of methyl substitution positions on the molecular properties of 1,3-dioxolane (DOL), a commonly used cyclic ether. The results show that the introduction of methyl groups can effectively inhibit the ring-opening polymerization of DOL. Besides, 4-methyl-1,3-dioxolane (4-Me DOL), with larger steric hindrance compared to 2-methyl-1,3-dioxolane (2-Me DOL), exhibits weaker solvation ability, favoring the formation of anion-rich inner solvation sheath layers and anion-derived interfaces. Even at conventional concentrations, 1 M LiFSI in 4-Me DOL (LiFSI/4-Me DOL) electrolyte demonstrates good LMA stability and an expanded electrochemical window up to 4.6 V. The Li-LiNi 0.5 Co 0.2 Mn 0.3 O 2 (NCM523) cell using LiFSI/4-Me DOL could stably cycle over 300 times. This work reveals a new design principle for solvent molecules.
研究领域:
材料科学
·
电化学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
ACS Sustainable Chemistry & Engineering
·
2025
·
IF 7.3
Xiaodong Cai,Yexin Yang,Huatong Yu,Danhua Jiao,Liangliang Xu,Daohai Zhang
Designing and synthesizing bio-based furandicarboxylic acid (FDCA)-based copolyesters with high thermal, mechanical, and modest hydrolytic properties present a significant challenge. In this study, poly(butylene furandicarboxylate) (PBF) was modified with the bio-based cyclic ether diol 2,5-tetrahydrofurandimethanol (THFDM). The resulting sustainable poly(butylene furandicarboxylate-co-hydroxymethyl tetrahydrofuran furandicarboxylate) (PBThFs) copolyesters displayed random microstructures with molecular weights (Mw) ranging from 20.8 to 62.6 × 103 g/mol. PBThFs transitioned from a partially crystalline to a fully amorphous state while maintaining thermal stability above 367 °C. The tensile strength and modulus of PBF were 49 and 1479 MPa, respectively, while PBThF15 (with a feed molar ratio of THFDM units at 15 mol %) showed improved values of 77 and 1855 MPa. Adding THFDM units significantly increased the glass transition temperature from 39.9 to 74.7 °C. The presence of ether linkages in THFDM modified the hydrolytic degradation of PBThF copolyesters compared to pure PBF. The hydrolysis mechanisms were clarified using Fukui function analysis and DFT calculations, indicating the increased susceptibility of PBThFs to hydrolysis. This study demonstrates the feasibility of synthesizing high-performance FDCA-based copolyesters, facilitating a broad spectrum of applications.
研究领域:
材料科学
·
化学工程
·
环境科学
✓ 已验证
产品关联
DOI
高影响因子
ACS Applied Materials & Interfaces
·
2024
·
IF 8.3
Yongxin Ma,Minghao Huang,Yejuan Xue,Xiaolong Wu,Weilong Kong,Yuxin Zhou,Heng Zhang,Hongfa Xiang,Zhimei Huang
Graphite anode suffers from great capacity loss and larger cell polarization under low-temperature conditions in lithium-ion batteries (LIBs), which are mainly caused by the high energy barrier for the Li+ desolvation process and sluggish Li+ transfer rate across the solid electrolyte interface (SEI). Regulating an electrolyte with an anion-dominated solvation structure could synchronously stabilize the interface and boost the reaction kinetics of the graphite anode. Herein, a highly ionic conductive electrolyte consisting of a fully methylated cyclic ether solvent of 2,2,4,4,5,5-hexamethyl-1,3-dioxolane (HMD) and fluoroethylene carbonate (FEC) cosolvent was designed. The high electron-donating effect and steric hindrance of −(CH3)2 in HMD endow the HMD-based electrolyte with high ionic conductivity but lower coordination numbers with Li+, and an anion-dominated solvation structure was formed. Such configuration can accelerate the desolvation process and induce the forming of a LiF-rich SEI film on the anode, avoiding the solvent coembedding into graphite and enhancing the ion migration rate under low temperatures. The assembled Li||graphite cell with the tame electrolyte outperformed the conventional carbonates-based cell, showing 93.8% capacity retention after 227 cycles for the DF-based cell compared to 64.7% after 150 cycles. It also exhibited a prolonged cycle life for 200 rounds with 81% capacity retention under −20 °C. Therefore, this work offers a valuable thought for solvent design and provides approaches to electrolyte design for low-temperature LIBs.
研究领域:
材料科学
·
电化学
·
能源存储
✓ 已验证
产品关联
DOI
PubMed
高影响因子
CHINESE JOURNAL OF CATALYSIS
·
2024
·
IF 15.7
Changpo Ma,Ying Lai,Tiange Zhao,Xiaoxuan Zhang,Haichao Liu,Weiran Yang
α,ω-Dicarboxylic acids are important intermediates for the preparation of polyamides , polyesters and polyurethanes . However, their production pathways are limited and usually suffer from low efficiency and environmental problems. Here, we report an innovative approach to synthesize C+2 dicarboxylic acids directly from cyclic ethers by dicarbonylation. Different from the general findings that C+1 monocarboxylic acids are produced by carbonylation of cyclic ethers involving alkene intermediates, in this work, by manipulating the reaction system with RhCl 3 and iodine in acetic acid, diiodide-substituted intermediates were selectively formed and subsequently converted to dicarboxylic acids in the presence of H 2 and CO. As high as 84% yield of adipic acid was obtained directly from tetrahydrofuran. This catalytic system is applicable not only to a wide variety of cyclic ethers but also to different primary diols to synthesize C2-elongated α,ω-dicarboxylic acids. This work provides a novel dicarbonylation strategy for the efficient synthesis of adipic acid, glutaric acid and other important α,ω-dicarboxylic acids (such as 1,7-heptanedioic acid and 1,8-octanedioic acid) that are still not easily synthesized by other methods.
研究领域:
有机化学
·
催化
·
材料科学
✓ 已验证
产品关联
DOI
高影响因子
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