- A new colorimetric and fluorescent chemosensor based on thiazolyl-hydrazone for sensitive detection of copper ions
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Abstract: A Cu2+-specific chemosensor probe thiazolyl-hydrazone (BL) has been designed and prepared, which provide tridentate chelate NNO coordination mode for Cu2+ with binding stoichiometry of 1:1. The BL solution exhibits a rapid color change from colorless to yellow along with a new intense absorption band at 414?nm upon binding to Cu2+ cation, whereas other metal cations do not induce such a change. The analytical detection limit is 0.75?μM, and the naked eye detection limit is as low as 20?μM. Additionally, the emission signal of BL could be quenched by Cu2+ and Fe3+ with a detection limit of 7.2?μM and 4.3?μM, respectively. Graphic abstract: [Figure not available: see fulltext.].
- Jia, Zhaodong,Wei, Jingna,Ren, Yaping,Zhang, Ning,Hao, Xin-Qi,Zhu, Xinju,Xu, Yan
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- Synthesis, crystal structures, optoelectronic properties and resistive memory application of π-conjugated heteroaromatic molecules
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Three π-conjugated small molecules DPBT, DEPBT and DEPBPy, based on bithiazole or bipyridine were designed and synthesized. In DEPBT and DEPBPy, the central core and terminal phenyl groups are connected by C[dbnd]C double bonds, whereas in DPBT, they are combined through C–C single bonds. The effects of the molecular structural changes on their crystal structures, optoelectronic properties and thin film morphologies were comparatively studied. In addition, their resistive memory performance was primarily investigated for the first time. Both DEPBT- and DEPBPy-based devices exhibit typical binary memory behavior, while DPBT-based device presents no memory property. The experimental results confirm that the introduction of C[dbnd]C bridged bonds into molecules could enhance the molecular interaction, which plays an important role in the molecular arrangement on the thin film, and has a significant contribution to charge transport in memory devices. This work demonstrates that aryl vinyl terminated bithiazoles and bipyridines both are good promising candidates for organic memory storage.
- Jia, Ming,Li, Yabo,Huang, Mengmeng,Kim, Jung Keun,Liu, Yingliang,Wu, Yangjie,Cao, Shaokui
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- Benzimidazolium salts with 1,4-dihydro-naphtho[1,8-ef]-1,4-diazepine: Synthesis, structure and recognition for copper(II) ion
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Two new benzimidazolium salts with the same cationic moiety and different anionic moieties 2-[2′-(N-benzyl-benzimidazoliumyl)]-1,4-dihydro-naphtho[1,8-ef]-1,4-diazepine bromide (1) and 2-[2′-(N-benzyl-benzimidazoliumyl)]-1,4-dihydro-naphtho[1,8-ef]-1,4-diazepine hexafluorophosphate (2) were prepared and characterized. The structure of 1 was determined by X-ray single crystal diffraction and 1H NMR and 13C NMR spectroscopy. Selective recognition of 2 for cations (Li+, Na+, K+, NH4+, Ag+, Ca2+, Co2+, Ni2+, Cu2+, Zn2+, Cr3+, Cd2+, Al3+, Pb2+, Hg+ and Hg2+, and use of their nitrate salts) was investigated by fluorescence and UV/vis titrations in C2H5OH/H2O (v:v?=?1:1) at 25?°C. The response of 2 to Cu2+ can be observed through both remarkable fluorescence enhancement and color change under sunlight (from yellow to red). The results indicated that 2 can distinguish Cu2+ from other cations via the instrument and naked eyes, and this is greatly convenient in practical operation.
- Liu, Qingxiang,Huo, Ran,Wei, Dengche,Zhao, Xiaojun,Zhao, Zhixiang,Cai, Kangqing
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- Method for alpha-position bromination of adjacent diketone
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The invention discloses a method for alpha-position bromination of adjacent diketone and belongs to the technical field of halogenating reaction. The method includes: adding adjacent diketone and bromate in a halogenated solvent, dropwise adding hydrogen bromide under the condition of 10-40DEG C, wherein molar ratio of adjacent diketone, bromate and hydrogen bromide is 1:0.7-1.2:2.0-5.0; after dropwise adding, slowly raising the temperature to be 30-50DEG C for stirring reaction, and 1-10 hours after stirring reaction, performing standing reaction for 2-12 hours at 30-50DEG C; after reaction,adding or not adding an extracting agent and taking a corresponding bromide product obtained from organic-phase separation. The bromate and hydrogen bromide which have oxidizability are taken as bromide reagents for bromination, high electricity and stable and safe reaction are achieved, generation of by-products is obviously reduced, yield is improved to some extent, and material transportation and storage is safe; in aftertreatment of feed liquid, the product can be separated by direct liquid separation, and the high-purity product can be obtained through simple distillation.
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Paragraph 0027
(2018/03/02)
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- Synthesis method of 3,3,4,4-tetrafluoropyrrolidine
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The invention discloses a synthesis method of 3,3,4,4-tetrafluoropyrrolidine and mainly solves the technical problems of poisonous introduced fluorine, relatively long steps and relatively low yield in the existing synthesis process. The synthesis method disclosed by the invention comprises four steps: firstly, mixing butanedione with chloroform, then, carrying out addition on the mixture and bromine to form 1,4-dibromo-2,3-butanedione; secondly, introducing sulfur tetrafluoride into the obtained 1,4-dibromo-2,3-butanedione, and carrying out a reaction to obtain 1,4-dibromo-2,2,3,3-tetrafluorobutane; thirdly, carrying out a high-temperature reaction on 1,4-dibromo-2,2,3,3-tetrafluorobutane and benzylamine to obtain 1-benzyl-3,3,4,4-tetrafluoropyrrolidine hydrochloride; and fourthly, carrying out catalytic hydrogenation debenzylation on 1-benzyl-3,3,4,4-tetrafluoropyrrolidine hydrochloride to obtain 3,3,4,4-tetrafluoropyrrolidine. The invention provides the synthesis method of 3,3,4,4-tetrafluoropyrrolidine which is relatively low in toxicity, low in raw material price, simple in operation and high in yield.
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Paragraph 0014; 0015; 0019; 0020; 0024; 0025
(2018/04/21)
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- NHC metal (silver, mercury, and nickel) complexes based on quinoxaline-dibenzimidazolium salts: Synthesis, structural studies, and fluorescent chemosensors for Cu2+ by charge transfer
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The two dibenzimidazolium salts 2,3-bis[(1-nPr- benzimidazoliumyl)methyl]quinoxaline hexafluorophosphate (H2-1a) and 2,3-bis[(1-Pi-benzimidazoliumyl)methyl]quinoxaline hexafluorophosphate (H 2-1b) (nPr = n-propyl and Pi = picolyl) and their four NHC metal complexes [Ag2(1a)2](PF6)2 (2a), [Hg(1a)(OAc)(H2O)]2(PF6)2 (2b), [Ag2(1b)2](PF6)2 (2c) and [Ni(1b)](NiCl4) (2d) have been synthesized and characterized. Each cation in 2a,c possesses a boxlike structure with different sizes. In 2b, one 18-membered macrometallacycle is formed by two bidentate NHC ligands and two mercury(II) atoms, in which an inversion center is observed. In 2d, one nickel(II) atom is surrounded by two carbene carbon atoms and two nitrogen atoms from two pyridine rings to adopt a square geometry. The recognition of Cu 2+ using 2a,c as chemosensors by charge transfer was investigated on the basis of fluorescence and UV/vis spectroscopic titrations. The results show that complexes 2a,c are effective chemosensors for Cu2+.
- Liu, Qing-Xiang,Yao, Zhao-Quan,Zhao, Xiao-Jun,Zhao, Zhi-Xiang,Wang, Xiu-Guang
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p. 3493 - 3501
(2013/07/26)
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- Kinetic study of the Ce(III)-, Mn(II)-, or ferroin-catalyzed Belousov-Zhabotinsky reaction with pyruvic acid
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Ce(III)-, Mn(II)-, or ferroin (Fe(phen)32+)-catalyzed reaction of bromate ion and pyruvic acid (PA) or its dimer exhibits oscillatory behavior. Both the open-chain dimer (parapyruvic acid, γ-methyl-γ-hydroxyl-α-keto-glutaric acid, DP
- Lin, Hsing-Lien,Yu, Yueh-O,Jwo, Jing-Jer
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p. 408 - 418
(2007/10/03)
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- Syntheses and Spectral Properties of New Dicyanopyrazine-Related Heterocycles from Diaminomaleonitrile
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A series of new dicyanopyrazine-related heterocycles such as quinoxalines, furopyrazines and pyrrolopyrazines were synthesized from diaminomaleonitrile.Their dicyanopyrazine moieties can also be converted to pyrazinoporphyrazines.The Wittig reaction of 2,3-bis(bromomethyl)-5,6-dicyanopyrazine and the ring-closure reactions of 2,3-dichloro-5,6-dicyanopyrazine were useful methodologies to extend the ? - conjugation giving new heterocycles.The absorption and fluorescence spectra of new compounds were correlated with their chemical structures.
- Jaung, Jae-yun,Matsuoka, Masaru,Fukunishi, Koushi
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p. 1301 - 1323
(2007/10/03)
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