JOURNAL OF CHEMICAL RESEARCH
·
2016
·
IF 0.661
Zhengyi Li,Yuan Chen,Yue Yin,Zhiming Wang,Xiaoqiang Sun
A simple and convenient two-step method has been developed and used to synthesise 25 (4 of which are novel) unsymmetrical N,N′-disubstituted thioureas in water. Alkylamines or variously substituted arylamines reacted smoothly with phenyl chlorothionoformate at room temperature to form thiocarbamates, which were then reacted with another alkyl- or arylamine in water at reflux to afford the unsymmetrical N,N′-disubstituted thioureas in good to excellent yields. Mild conditions, simple work-up, high yields as well as using water as solvent are the major advantages of the method.
研究领域:
有机化学
·
绿色化学
✓ 已验证
DOI
高影响因子
JOURNAL OF APPLIED ELECTROCHEMISTRY
·
2018
·Vol. 48
·期 10
·1121-1129
·
IF 2.262
Zhu Chun-Rong,Long Jun-Fei,Tang Qian,Gong Cheng-Bin,Fu Xiang-Kai
Abstract This paper aims to develop a multi-colored electrochromic device based on mixed mono- and bi-substituted 4,4′-bipyridine derivatives containing an ester group. A series of these derivatives were synthesized, and their electrochemical and electrochromic properties were studied through cyclic voltammetry and ultraviolet–visible spectroscopy. The mono- and bi-substituted 4,4′-bipyridine derivatives containing an ester group displayed different onset bias and colored state. Mono-substituted 4,4′-bipyridine derivatives showed a magenta colored state at an onset bias of − 1.3 V; bi-substituted 4,4′-bipyridine derivatives showed violet colored states at an onset bias of − 0.8 V. A multi-colored electrochromic device was achieved by mixing mono- and bi-substituted 4,4′-bipyridine derivatives as the electrochromic layer. Graphical Abstract
研究领域:
材料科学
·
电化学
✓ 已验证
产品关联
DOI
高影响因子
Inorganic Chemistry Frontiers
·
2022
·Vol. 10
·期 3
·804-814
·
IF 7.779
Hu Yao,Yinan Zheng,Siliang Yue,Songjie Hu,Wenyu Yuan,Xiaohui Guo
The oxygen evolution reaction (OER) has slow chemical dynamics in the electrochemical decomposition of water. Herein, we demonstrate that B-site substitution engineering on ABF3 is an efficient strategy to boost the OER activity due to the modified electronic structure. A series of perovskite fluorides with the formula NaCo1−2xFexNixF3 were fabricated via a simple hydrothermal process, in which Co was partially substituted by both Fe and Ni. The optimized perovskite fluoride exhibited a low overpotential of 265 mV at a current density of 10 mA cm−2 and outstanding electrochemical stability after 100 h continuous electrocatalysis for the OER. These results are superior to the state-of-the-art perovskite-based OER catalysts. The X-ray photoelectron spectroscopy (XPS) and X-ray absorption fine structure (XAFS) results showed that the dual-substitution of Fe and Ni atoms not only produced higher valence Co3+ ions but also generated the more active species Fe3+. In addition, the produced metal oxyhydroxides (MOOH, M = Co, Fe, Ni) on the catalyst surface during OER activation could contribute both excellent catalytic activity and ultralong stability.
研究领域:
材料科学
·
电化学
✓ 已验证
产品关联
DOI
高影响因子
Materials Chemistry Frontiers
·
2025
·
IF 6.4
Zhen Qian,Deman Kong,Hongping Wu,Hongwei Yu,Zhanggui Hu,Jiyang Wang,Yicheng Wu
Infrared nonlinear optical (IR NLO) crystals are crucial for advancing laser technology; however, designing and synthesizing high-performance IR NLO materials remain challenging. Heteroanionic materials effectively integrate the advantages of single-anionic counterparts, offering a promising route for synthesizing high-performance IR NLO materials. Herein, two novel heteroanionic oxychalcogenide IR NLO crystals, Sr2MgSn2OS6 and Sr2SnGa2OS6, are synthesized by a double substitution strategy based on the single-anionic oxide Sr2MgSi2O7. They exhibit excellent optical performance, including a large phase-matched (PM) second harmonic generation (SHG) response (2 × AgGaS2), a wide optical band gap (Eg > 3.0 eV), a large birefringence (Δn = 0.128–0.173), and a high laser-induced damage threshold (7 × AgGaS2). The structure–performance relationship analysis indicates that these excellent performances are mainly attributed to the hybridized functional moieties. These findings strongly indicate the potential of these materials as suitable IR NLO candidates, and the strategy of double substitution proves to be effective for designing novel high-performance NLO crystals.
研究领域:
材料科学
·
光学
✓ 已验证
产品关联
DOI
高影响因子
ACS Applied Materials & Interfaces
·
2021
·
IF 9.229
Guofeng Jia,Faqiang Li,Jue Wang,Suqin Liu,Yuliang Yang
A dual substitution strategy is introduced to Co-free layered material LiNi0.5Mn0.5O2 by partially replacing Li and Ni with Na and Al, respectively, to achieve a superior cathode material for lithium ion batteries. Na+ ion functions as a “pillar” and a “ cationic barrier” in the lithium layer while Al3+ ion plays an auxiliary role in stabilizing structure and lattice oxygen to improve the electrochemical performance and safety. The stability of lattice oxygen comes from the binding energy between the Ni and O, which is larger due to higher valences of Ni ions, along with a stronger Al–O bond in the crystal structure and the “cationic barrier” effect of Na+ ion at the high-charge. The more stable lattice oxygen reduces the cation disorder in cycling, and Na+ in the Li layer squeezes the pathway of the transition metal from the LiM2 (M = metal) layer to the Li layer, stabilizing the layered crystal structure by inhibiting the electrochemical-driven cation disorder. Moreover, the cathode with Na–Al dual-substitution displays a smaller volume change, yielding a more stable structure. This study unravels the influence of Na–Al dual-substitution on the discharge capacity, midpoint potential, and cyclic stability of Co-free layered cathode materials, which is crucial for the development of lithium ion batteries.
研究领域:
材料科学
·
能源存储
✓ 已验证
DOI
高影响因子
Small
·
2024
·Vol. 21
·期 8
·2409041
·
IF 13
Zhijian Huang,Mingpei Tan,Ming Liu,Yukai Hua,Yong Liu
Na 0.67 Ni 0.33 Mn 0.67 O 2 (NNM) is regarded as a promising cathode material for Na-ion batteries (NIBs), but suffers from irreversible phase transformations characterized by multiple voltage plateaus, resulting in poor cycle stability and inferior rate capability. To address these issues, the Na 0.67 Ni 0.18 Cu 0.10 Zn 0.05 Mn 0.67 O 2 (NNCZM) cathode material is synthesized by a cation chelation and reassembly process, which can promote a more uniform element distribution than that prepared by the solid-state method (S-NNCZM), resulting in better Na + diffusion kinetics and rate capability. Replacing Ni 2+ with a small amount of Zn 2+ prevents the P2-O2 phase transformation, while replacing Ni 2+ with an appropriate amount of electrochemically active Cu 2+ eliminates Na-vacancy ordering and additionally contributes to capacity. Thus, the dual substitution of Cu 2+ and Zn 2+ for Ni 2+ makes the NNCZM electrode synergistically achieve a complete solid solution reaction and better cycling stability. Accordingly, it exhibits a large discharge capacity (110.2 mA h g −1 at 10 mA g −1 ) with a high initial coulombic efficiency (97.3%), remarkable cycle stability with 84.1% capacity retention over 200 cycles at 200 mA g −1 , and excellent rate capability with a discharge capacity of 61.0 mA h g −1 at 2000 mA g −1 , significantly outperforming the NNM and S-NNCZM electrodes.
研究领域:
材料科学
·
电化学
✓ 已验证
DOI
高影响因子
NEW JOURNAL OF CHEMISTRY
·
2025
·
IF 2.5
Lin Yin,Chen-xin Yang,Yu-xuan Han,Hao Zhang,Feng-lu Jiang,Wen-tao Zhong,Chengbin Gong,Qian Tang
This work aims to investigate the electrochromic behavior of an asymmetric disubstituted viologen containing a quaternary ammonium group in semi-solid hydrogel state electrochromic devices. An asymmetric disubstituted viologen BTMAPP3+3〖Br〗^- was synthesized as the electrochromic material, and two symmetric disubstituted viologens (DTMAPP4+4〖Br〗^- and DBP2+2〖Br〗^-) were synthesized as the control electrochromic materials. Polyacrylamide hydrogel state ECDs based on three electrochromic materials were assembled by in-situ photo-initiated polymerization of acrylamide under UV light, and their electrochemical and electrochromic performance were investigated. They showed similar electrochemical performance. They also required a same working voltage and achieved a similar color change from colorless bleached state to blue-purple colored state. It’s noteworthy that the ECD based on BTMAPP3+3〖Br〗^- showed a better cycling stability (retaining of the initial optical contrast after 16,000 s monitored: 95.6% versus 70.7% and 78.5%) and a higher coloration efficiency (115 cm2/C versus 96 cm2/C and 103 cm2/C) compared to the PAM ECDs based on two symmetric disubstituted viologen. The results indicate that an asymmetric disubstituted viologen containing a quaternary ammonium group can enhance the cycling stability of the gel-state ECD through suppressing the formation of radical cation dimers. The all-in-one semi-solid hydrogel state ECDs based on BTMAPP3+3〖Br〗^- with advantages of easy-to-make process, good cycling stability, low operating voltage, high coloration efficiency and low power consumption offer a new choice for electronic labels, solar cell powered displays, smart windows, etc.
研究领域:
材料科学
·
电化学
·
高分子科学
·
光学材料
·
能量存储与转换
✓ 已验证
产品关联
DOI
高影响因子
Polymer Chemistry
·
2019
·Vol. 10
·期 18
·2290-2297
·
IF 4.76
Yingjie Zhang,Yi Wu,Riwei Xu,Jianping Deng
Substantial progress has been made in preparing and applying particles constructed from monosubstituted polyacetylenes. For disubstituted acetylenes, however, it still remains a big academic challenge on how to prepare polymer particles from monomers, majorly due to the relevant polymerizations requiring water-sensitive metal catalysts. This article establishes the first protocol for preparing regular particles constructed from disubstituted polyacetylenes through precipitation polymerization. Two disubstituted acetylenic monomers underwent precipitation polymerization and the corresponding polymer particles with narrow size distribution were obtained smoothly. CD and UV-vis absorption spectra demonstrated that the disubstituted polyacetylenes forming optically active particles adopted chiral helical conformations. Effects of solvent composition and catalyst amount on the particles were studied in detail. A mechanism was then proposed for understanding the formation of particles. The study provides a universal, facile and straightforward way to prepare polymer particles from disubstituted polyacetylenes.
研究领域:
高分子化学
·
材料科学
·
纳米技术
·
手性材料
·
功能高分子
✓ 已验证
DOI
高影响因子
TETRAHEDRON
·
2016
·
IF 2.645
Yufei Wu,Jie Hou,Yuliang Liu,Mingfu Zhang,Chen-Ho Tung,Yifeng Wang
The highly efficient and chemoselective α,α′-bis-substitution of alkanones is important in organic synthesis. Herein, a dimeric titanium cluster, Ti 2 Cl 2 (OPr i ) 6 ·2HOPr i ( Ti 2 ), is used in the Claisen–Schmidt condensation reaction, for the selectively activation of symmetrical ketones containing α,α′-methylene groups and production of α,α′-bis-substituted alkanones in high efficiency and chemoselectivity. The high efficiency and chemoselectivity can be extended to a variety of typical alkanones and aromatic aldehydes . Both of the oxo-bridged dimeric motif of Ti 2 and the ionic Ti–Cl bond are responsible for the high efficiency and chemoselectivity.
研究领域:
有机化学
·
催化
·
无机化学
✓ 已验证
产品关联
DOI
高影响因子
危险品化学品经营许可证（带存储）