- Functional Two-Dimensional Coordination Polymer Exhibiting Luminescence Detection of Nitroaromatics
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A polyfluorinated-aromatic carboxylic acid has been designed and synthesized by the acylation reaction, tetrafluoro-bis(3,5-dicarboxyphenyl)terephthalamide (H4 bdtfa), which assembled with Zn2+ ions in the mixed solvents of DMF, py, and H2O under solvothermal conditions to produce a two-dimensional (2D) coordination polymer (CP), {[Zn2(bdtfa)(py)3(H2O)]·2DMF}n (1), (py = pyridine, DMF = N,N′-dimethylmethanamide). The final structure has been carefully characterized by various methods including single-crystal X-ray diffraction, powder X-ray diffraction (PXRD), infrared (IR) spectroscopy, and thermogravimetric analysis. Two types of four-coordinated Zn2+ centers present a 2D "sql"-type layer through bdtfa4- ligands, and the adjacent layers are connected through hydrogen bonds and π?π stacking interactions to produce a three-dimensional supramolecular framework. Luminescent results reveal that CP 1 can be regarded as a highly sensitive sensor for detecting nitroaromatics based on the fluorescence quenching effect. Moreover, the reason for the luminescent response of CP 1 toward nitroaromatics has been investigated by theoretical calculations, which indicates that the reason for the quenching can be primarily due to the energy- and electron-transfer as well as the electrostatic interaction between nitroaromatics and CP 1.
- Tang, Zilong,Chen, Hongjuan,Zhang, Yong,Zheng, Baishu,Zhang, Shaowei,Cheng, Peng
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- Assembly Pattern of Supramolecular Hydrogel Induced by Lower Critical Solution Temperature Behavior of Low-Molecular-Weight Gelator
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Although the gelation process and lower critical solution temperature (LCST) behavior are well acknowledged in polymer systems, low-molecular-weight gelators (LMWGs) rarely display LCST behavior during supramolecular gelation. Herein, we report an LMWG system with LCST-type thermoresponsiveness and an LCST-triggered supramolecular gelation process. Temperature plays a crucial role in this system, not only affecting the LCST phase separation but also triggering the gelation process. The backbones (three-dimensional structures) of the resulting hydrogel are the hierarchical assemblies of the LMWG undergoing the LCST phase separation. Hence, the gelation of the LMWG is only realized when the gelation temperature is above the critical transition temperature (Tcloud) of the LCST behavior, which is different from many supramolecular or polymeric hydrogel systems.
- Wu, Shuanggen,Zhang, Qiao,Deng, Yan,Li, Xing,Luo, Zheng,Zheng, Bo,Dong, Shengyi
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supporting information
p. 448 - 455
(2020/01/09)
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- Extending the series of p-substituted tetrafluorobenzoic acids: synthesis, properties and structure
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The synthesis of the derivatives of p-aminotetrafluorobenzoic acid, p-H2NC6F4CO2H (2b), by hydrolysis, acylation or interaction with aldehydes was developed giving H2NC6F4CO2K (2a), C6F5C(O)N(H)C6F4CO2Et (3) and (E)-ArCH[dbnd]NC6F4CO2Et (4–11). The chemical derivatization of tetrafluoroterephthalic acid, p-HO2CC6F4CO2H (12), by hydrolysis, etherification and reduction was performed giving a number of symmetrical X(O)CC6F4C(O)X (13–15; X?=?Cl, NEt2, OMe) or unsymmetrical YC6F4CO2Me (15a–b, 16, 18–21; Y?=?CO2K, CO2H, CH2OH, C(O)Cl, C(O)C6H3(i-Pr)2, CO2CH2C6F4CO2Me, CO2C6H4Bu-t), HOCH2C6F4CO2H (17), [MeO2CC6F4]2Y (22, 23; Y?=?OCH2CH2O, N(H)C6H4N(H)) compounds. All substances were thoroughly investigated by spectroscopic methods (multinuclear NMR and IR spectroscopy, mass-spectrometry). The molecular structures of p-H2NC6F4CO2Et (2) and p-HO2CC6F4CO2Me (15b) have been determined by X-ray diffraction analysis.
- Zaitsev, Kirill V.,Oprunenko, Yuri F.,Lermontova, Elmira Kh.,Churakov, Andrei V.
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- Synthesis method of 2,3,5,6-tetrafluoro-7,7,8,8-tetracyanoquinodimethane
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The invention discloses a synthesis method of 2,3,5,6-tetrafluoro-7,7,8,8-tetracyanoquinodimethane and relates to the technical field of organic electroluminescent materials. On the basis of simplifying the synthesis method, wastewater generated by post-treatment is reduced, and the safety of a synthesis process is improved, so that the synthesis method is applicable to industrial production. The synthesis method comprises the following steps: firstly, carrying out a condensation reaction by taking 2,3,5,6-tetrafluoroterephthaloyl chloride andtrialkylsilyl cyanide as raw materials under an oxygen-free and dry environment to obtain an intermediate; and then, removing trialkylsiloxy in the intermediate to obtain F4-TCNQ. The synthesis method of the 2,3,5,6-tetrafluoro-7,7,8,8-tetracyanoquinodimethane, disclosed by the invention, is used for synthesizing organic electroluminescent materials.
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Paragraph 0113
(2017/06/08)
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- REACTION OF PERFLUORINATED METHYL- AND ALKENYLBENZENES WITH INORGANIC OXIDES IN THE PRESENCE OF ANTIMONY PENTAFLUORIDE
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A study was carried out on the reaction of perfluorinated toluene, m-xylene, p-xylene, mesitylene, and m-(1-propenyl)toluene with inorganic oxides in the presence of antimony pentafluoride.Depending on the reaction conditions, polyfluorinated acids resulting from the consecutive conversion of trifluoromethyl groups into carboxylic acid groups are obtained after hydrolysis of the reaction mixtures.
- Karpov, V. M.,Panteleev, I. V.,Platonov, V. E.
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p. 1932 - 1938
(2007/10/02)
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