LIQUID CRYSTALS
·
2020
·
IF 2.908
Shenghua Du,Mengting Zhang,Pei Chen,Jiazhen Dang,Aiai Gao,Weisong Du,Xinbing Chen,Zhongwei An
With altering molecular dipole moments via lateral fluoro atom and π-conjugation through carbon–carbon triple bond, improved mesomorphic behaviour is achieved for new kind of fluorinated mesogenic compounds containing ethynyl and 1-methyl-1H-benzimidazole moieties, namely, 2-[4-[2-[4-(alkoxy) phenyl]ethynyl]-3-fluorophenyl]-1-methyl-1H-benzimidazole derivatives (nPEF(3)PMx). The compounds nPEF(3)PMx mainly display enantiotropic nematic mesophases with mesophase ranges of 27.1–59.1 °C and 62.7–96.7°C on heating and cooling for nPEF(3)PMH, 59.499.1°C and 96.2–144.6°C for nPEF(3)PMM, and 101.6–109.4°C and 104.9–157.2°C for nPEF(3)PMN (n < 8), respectively. Compared with nonfluorinated reference analogues I, nPEF(3)PMx give obviously lower melting points and much wider or comparable nematic mesophase ranges, meanwhile, they show much lower melting points and higher nematic mesophase stability than reference analogues II because of their reduced molecular dipole moments and enhanced π-conjugation. In addition, the compounds nPEF(3)PMx are composed of benzene ring, ethynyl bridge and benzimidazole mesogenic unit, therefore, they have high birefringence of 0.48–0.62 resulted from their large π-conjugated molecule. The result indicates that nPEF(3)PMx has a potential application in liquid crystal mixture.
研究领域:
材料科学
·
化学
✓ 已验证
产品关联
DOI
高影响因子
MOLECULES
·
2019
·Vol. 24
·期 5
·891
·
IF 3.06
Ye Liu,Jiaqi Liu,Renmei Zhang,Yan Guo,Hongbo Wang,Qingguo Meng,Yuan Sun,Zongliang Liu
3,4-dihydropyrimidin-2(1H)-one compounds (DHPMs) possess extensive biological activities and are mainly prepared via Biginelli reaction and N-alkylation. In the present study, selective alkylation of N1was investigated by using tetrabutylammonium hydroxide. In vitro cytotoxicity study on all synthesized compounds demonstrated that introduction of the aryl chain in the R3as well as the low electron-donating group in the R1of DHPMs contributed to the anti-proliferative potency. A larger value of the partition coefficient (Log P) and suitable polar surface area (PSA) values were both found to be important in order to maintain the antitumor activity. The results from in vivo study indicated the great potential of compound3dto serve as a lead compound for novel anti-tumor drugs to treat glioma. Pharmacophore study regarding the structure-activity relations of DHPMs were also conducted. Our results here could provide a guide for the design of novel bioactive 3,4-dihydropyrimidin-2(1H)-one compounds.Keywords:3,4-dihydropyrimidin-2(1H)-ones;N1-alkylation;structure-activity relationship;in vivo experiments;anticancer activities
研究领域:
药物化学
·
药理学
·
癌症研究
✓ 已验证
产品关联
DOI
PubMed
高影响因子
CHINESE JOURNAL OF CHEMICAL ENGINEERING
·
2023
·
IF 3.8
Bowen Jiang,Meiling Weng,Jigang An,Yuewei Fan,Jia Liu,Ying Liu,Ting Yu,Leizhi zheng,Guoqiang Yang,Zhibing Zhang
The transformation of CO 2 into high value-added product is a promising pathway for utilizing CO 2 . However, the process tends to require harsh reaction conditions owing to CO 2 chemical inertness. Designing a high efficiency catalytic system with environmentally benign characteristic are important determinants. In this work, protic ionic liquids [TMG][2-OPy] were prepared via one-step neutralization between 1,1,3,3-tetramethylguanidine and 2-hydroxypyridine, applying to the domain of synthesizing quinzoline-2,4(1H , 3H) - diones from CO 2 and 2-aminobenzontiles without any solvent or metal, achieving the yield of 97% at 90 °C for 8 h under atmospheric. A series of substrates with good to acceptable yield were detected, revealing the generality and universality of the catalyst. Furthermore, the system could be facilely reused for at least six runs, retaining the yield of 94%. A preliminary kinetic equation is calculated with the activation energy of 68 kJ·mol −1 , and a plausible reaction mechanism was put forward. This study highlights that the [TMG][2-OPy] enables to activate CO 2 carboxylation efficiently.
研究领域:
化学
·
环境科学
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF APPLIED POLYMER SCIENCE
·
2022
·Vol. 140
·期 8
·e53520
·
IF 3.057
Yimei Chen,Wei Yang,Juan Liu,Yuanliang Wang,Yanfeng Luo
2-Ureido-4[1 H ]-pyrimidone (UPy) can form strong quadruple hydrogen bonding (H-bonding) and is widely used to construct supramolecules. Though the H-bonding assembly of UPy-containing polymers has been widely reported, little attention is paid to the H-bonding characteristics and mechanism of UPy-containing polyurethanes. Here, by using UPy- p -PDLLA-SMPU, a linear polyurethane with multiple pendant UPy units as the model polymer, the H-bonding assembly characteristics in solution, solid film and melt are systematically investigated. It is found that the UPy units mainly exist as free monomers in DMSO, UPy dimers in CHCl 3 , and both free monomers and dimers in DMF. The dimerization of UPy can promote the H-bonding of urea and urethane groups and thus the formation of hard segment aggregates. Thereby, the thermal resistance and reversibility of the H-bonds are significantly enhanced in both UPy- p -PDLLA-SMPU film and melt. UPy- p -PDLLA-SMPU can transition from a rubber state (70°C–85°C) to a viscous flow state (≥120°C), presenting the characteristics of both chemically crosslinked and linear polyurethanes. This work provides a clear picture on the H-bonding assembly of UPy units together with urea and urethane groups in UPy- p -PDLLA-SMPU. The obtained assembly characteristics and mechanism are beneficial for the design and processing of UPy-based physically crosslinked polyurethanes.
研究领域:
高分子化学
·
材料科学
✓ 已验证
产品关联
DOI
高影响因子
MONATSHEFTE FUR CHEMIE
·
2022
·Vol. 153
·期 3
·257-266
·
IF 1.613
Zhang Dawei,Ren Lu,Liu Ailing,Li Wenyu,Liu Yuxin,Gu Qiang
An efficient synthesis of 1,3,5-trisubstituted 1 H -pyrazoles was developed. 1,3,5-Trisubstituted-1 H -pyrazoles were synthesized starting from α , β -unsaturated aldehydes/ketones and hydrazine using catalyst H 3 [PW 12 O 40 ]/SiO 2 under microwave irradiation and solvent-free conditions (74–90%) and were characterized by HR-MS, FT-IR, 1 H NMR, and 13 C NMR spectroscopy. It was found that silica had a good loading and dispersing effect on phosphotungstic acid and could effectively absorb microwave energy to promote the condensation reaction. The merits of the method included the environmental friendly reaction conditions, simple operation, extensive substrates, good yields, and reuse of the H 3 [PW 12 O 40 ]/SiO 2 . Moreover, the crystal structure of compound 1-(4-chlorophenyl)-5-(2-methoxyphenyl)-3-(4-nitrophenyl)-1 H -pyrazole in triclinic P-1 space group was presented. Graphical abstract
研究领域:
有机化学
·
绿色化学
✓ 已验证
DOI
高影响因子
LIQUID CRYSTALS
·
2013
·
IF 1.959
Lina Zhang,Xinbing Chen,Fengqi Zhao,Xuezhong Fan,Pei Chen,Zhongwei An
Three series of 2-(4′-alkoxybiphenyl-4-yl)-1H-benzimidazole derivatives (nM-x), which possessed 5-nitrobenzimidazole (nM-N series), benzimidazole (nM-H series) or 5-methylbenzimidazole (nM-M series) units at the end of the molecule, were synthesised and characterised by infrared, 1H- and 13C-nuclear magnetic resonance spectra, electrospray ionisation-mass spectrometry and elemental analysis. Their phase transition behaviour was investigated by differential scanning calorimetry, polarising optical microscopy and X-ray diffraction. All the compounds exhibited enantiotropic smectic mesophases with wide temperature domains for a carbon number in the alkoxy chain from 6 to 16, where the mesophase ranges were 14–91°C and 17–99°C during heating and cooling processes for the nM-N compounds, 7–25°C and 8–49°C for the nM-H compounds and 48–81°C and 52–85°C for the nM-M compounds, respectively. The effect of the length of alkoxy chain on mesomorphic properties was discussed. The nM-N and nM-M exhibited a much wider mesophase range whether during heating or cooling process than the corresponding nM-H series, especially for the longer terminal chain (n > 8), which indicated that the substituent in the benzimidazole moiety was helpful in increasing the mesophase stability.
研究领域:
有机化学
·
材料科学
✓ 已验证
DOI
高影响因子
Canadian Journal of Chemistry
·
2018
·Vol. 97
·期 3
·
IF 1.084
Guo-Ying Zhao,Ling-Ling Mu,Latif Ullah,Meng Wang,Hong-Ping Li,Xin-Xin Guan
In this study, pharmaceutically relevant quinazoline-2,4(1H,3H)-diones were synthesized eco-efficiently by cycloaddition of CO2 and 2-aminobenzonitrile in water, catalyzed by melamine as a thermoregulated catalyst. Quinazoline-2,4(1H,3H)-dione was produced selectively with 92% yield at 120 °C, 4.2 MPa, and automatically separated from the hot catalytic aqueous solution, which was reused directly for several runs until its activity decreased in an obvious manner. Then, the catalyst melamine was recrystallized from the spent aqueous solution via simple cooling and reused for another several catalytic runs. The efficient valorization of CO2 and the straightforward stepwise recovery of the products and catalyst were important to save energy and minimize process waste for the practical industrial production.
研究领域:
有机化学
·
绿色化学
✓ 已验证
产品关联
DOI
高影响因子
RESEARCH ON CHEMICAL INTERMEDIATES
·
2022
·Vol. 48
·期 3
·983-1001
·
IF 3.134
Zhang Dawei,Ren Lu,Liu Ailing,Zhang Yumin,Lv Yang,Gu Qiang
Abstract An efficient synthesis of 1,3,5-trisubstituted-1 H -pyrazoles was developed via cyclocondensation in 78–92% yields starting from α , β -unsaturated aldehydes/ketones with substituted phenylhydrazine using vitamin B 1 as a catalyst, and was characterized by HR-MS, FT-IR, 1 H NMR and 13 C NMR spectroscopy. The reaction has simple operation, metal-free catalysis, acid or base free catalysis. As a green catalyst, vitamin B 1 was found to possess favorable catalytic activity and reusability for the condensation reaction. 1,3,5-trisubstituted-1 H -pyrazole shows from orange-red to cyan in different solvents when the electron withdrawing group is attached to acetophenone (taking compound 5i as an example). Compound 5i as a metal ion fluorescent probe has excellent selectivity for Ag + detection. The crystal structure of the compound 3-(4-chlorophenyl)-1,5-diphenyl-4,5-dihydro-1 H -pyrazole ( 5b ) in the orthorhombic space group Pca 21 was presented and formed racemic crystals. Graphical abstract
研究领域:
有机化学
·
材料科学
·
分析化学
✓ 已验证
产品关联
DOI
高影响因子
Crystals
·
2022
·Vol. 12
·期 7
·948
·
IF 2.67
Haolong Zhai,Xiaoping Cui,Yuping Gan
Taking the combustion tear gas mixture as the research object, the system formula was optimized by adding a different mass fraction of 5-amino-1H-tetrazole(5AT). TG-DSC, a thermocouple, and a laser smoke test system were used to characterize the characteristic combustion parameters such as combustion temperature and velocity, as well as the end-point effects such as smoke concentration and particle size. Starink’s method, the Flynn–Wall–Ozawa method, and the Coats–Redfern method were used to evaluate the pyrolysis kinetic parameters of the samples. The results show that when the mass fraction of 5-amino-1H-tetrazole in the system is 10%, the maximum combustion temperature of the sample decreases by nearly 70 °C and the smoke concentration increases by 12.81%. The kinetic study also found that with a different mass fraction of 5-amino-1H-tetrazole in the system, the main reaction model of the mixed agent in the first, third, and fourth stages of pyrolysis changed significantly, but for the second stage of sample pyrolysis, the main reaction model (the A4 model) showed a high degree of consistency, which can be considered as the thermal diffusion stage of the tear agent capsicum oleoresin (OC) (the temperature range is 220~350 °C), which is highly consistent with the results of the TG-DSC analysis. It was also confirmed that OC’s thermal diffusion is mainly concentrated in this stage. The results of this study show that adding an appropriate amount of the combustible agent 5-amino-1H-tetrazole to the combustion tear gas mixture can improve its combustion performance and smoking performance, which provides an important, new idea for the development of a new generation of safe, efficient, and environmentally friendly tear gas mixtures.Keywords:5-amino-1H-tetrazole;tear gas mixture;combustible agent;combustion pyrolysis characteristics;dynamics research
研究领域:
化学
·
材料科学
·
热分析
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF COORDINATION CHEMISTRY
·
2015
·
IF 2.012
Cui-Cui Wang,Jin-Hua Wang,Gui-Mei Tang,Yong-Tao Wang,Yue-Zhi Cui,Seik Weng Ng
Three new metal coordination polymers constructed from adipic acid and 2-(pyridin-3-yl)-(1H)-benzimidazole ligands, [M(ADP)(3PBI)2(H2O)2]·2H2O (M = Ni and Co for 1 and 2, respectively) and [Cd(ADP)(3PBI)(H2O)] (3) [ADP = adipic acid dianion; 3PBI = 2-(pyridin-3-yl)-(1H)-benzimidazole], have been synthesized by hydrothermal reactions and were characterized by X-ray single-crystal diffraction, elemental analyses, IR, powder X-ray diffraction, and thermogravimetry. Complexes 1 and 2 are isostructural. Both form a 1-D linear chain structure, which is further assembled into a 3-D supramolecular framework by π⋯π stacking and hydrogen bonding interactions. Complex 3 possesses a binuclear unit and displays a 2-D layer which is further extended to a 3-D supramolecular architecture via hydrogen bonding and other weak packing interactions. The luminescent properties of 3 were investigated in the solid state at room temperature.
研究领域:
化学
·
材料科学
✓ 已验证
产品关联
DOI
高影响因子
THERMOCHIMICA ACTA
·
2024
·
IF 3.1
Zhen-Li Yang,Ya-Dong Yao,Jian-Guo Zhang,Qiang Xie,Feng Liu,Zhi-Wei He,Zu-Jia Lu
The construction and comprehensive characterization of energetic ionic salts 5-amino-3-hydrazinyl-1 H -1,2,4-triazolium diperchlorate (2) and 5-amino-3-hydrazinyl-1 H -1,2,4-triazolium 3-nitro-1,2,4-triazolate-5-one (3), which are based on 5-amino-3-hydrazinyl-1 H -1,2,4-triazole, were conducted. Differential scanning calorimetry (DSC) and thermogravimetric analysis (TGA) were employed to explore the thermal and kinetic behaviors of the novel energetic ionic salts. An isoconversional approach and non-linear regression analysis were employed to propose accurate kinetic models for characterizing the decomposition of the energetic ionic salts based on the data from DSC and the most possible mechanism functions governing the decomposition of 2 and 3 was determined. Furthermore, experimental measurements and theoretical calculations were employed to examine diverse physicochemical characteristics, including densities, mechanical sensitivities, heat of formation as well as detonation parameters. The findings suggest that salt 2 exhibits a good detonation pressure of 37.4 GP and a satisfactory detonation velocity of 9031 m/s, exceeding RDX in terms of energy content and suggesting its potential as a viable high-energy explosive substitute for RDX. While salt 2 exhibits a slightly lower level of detonation performance than HMX, it possesses better sensitivity, which mean that salt 2 retains a considerable potential for valuable applications.
研究领域:
化学
·
材料科学
·
爆炸科学
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF HETEROCYCLIC CHEMISTRY
·
2023
·
IF 2.4
Ping Zhao,Qingle Zeng
We have developed a diversity-oriented, substrate-controlled, chemoselective synthetic method for a variety of structurally diverse 1-sulfonylquinazoline-2,4(1H,3H)-diones and 2-sulfonamidobenzonitriles. This substrate-controlled synthesis is accomplished through the condensation reaction of 2-(sulfonamido)benzamides with or without an N-methyl group on the amides. The reactions are fulfilled within half an hour at room temperature with solid triphosgene as a convenient condensing agent and pyridine as an acid acceptor. This protocol features easily available starting materials, mild reaction conditions, easy experimental operation, and moderate to excellent yields of products.
研究领域:
有机化学
·
药物化学
✓ 已验证
DOI
高影响因子
危险品化学品经营许可证（带存储）