JOURNAL OF CHEMICAL RESEARCH
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2013
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IF 0.596
Xiao-Chuan Jia,Jing Li,Zhi-Rui Yu,Yu-Hu Wang,Lei Zhou,Yan-Yan Yu
Deprotection of phenylhydrazones and tosylhydrazones to their parent aldehydes and ketones has been accomplished using iodobenzene as catalyst in the presence of mCPBA as the terminal oxidant at room temperature. The reaction is general, and the target products can be obtained in good to excellent yields.
研究领域:
有机化学
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合成化学
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DOI
高影响因子
Marine Drugs
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2017
·Vol. 15
·期 7
·223
·
IF 3.503
Na Li,Huanhuan Wang,Xiaosai Qu,Yu Chen
ROMP is an effective method for preparing functional polymers due to its having characteristics of “living” polymerization and rapid development of catalysts. In the present work, poly(norbornene-methylamine), a mimic of chitosan, was synthesized via ROMP reaction. The amino-protected product, 5-norbornene-2-(N-methyl)-phthalimide, was prepared by a reaction of 5-norbornene-2-methylamine with phthalic anhydride, which was then subjected to the ROMP reaction in the presence of Hoveyda-Grubbs 2nd catalyst to afford poly(norbornene-(N-methyl)-phthalimide). The target product, poly(norbornene-methylamine), was obtained by deprotection reaction of poly(norbornene-(N-methyl)-phthalimide). The products in each step were characterized by FTIR and1H-NMR, and their thermal stabilities were determined by TG analysis. The effects of molar ratio between monomer ([M]/[I]) and catalyst on the average relative molecular weight (Mn¯) and molecular weight distribution of the produced polymer products were determined by gel permeation chromatography (GPC). It was found that theMn¯of poly(norbornene-(N-methyl)-phthalimide) was controllable and exhibited a narrow polydispersity index (PDI) (~1.10). The synthesis condition of 5-norbornene-2-(N-methyl)-phthalimide was optimized by determining the yields at different reaction temperatures and reaction times. The highest yield was obtained at a reaction temperature of 130 °C and a reaction time of 20 min. Our work provides a new strategy to synthesize polymers with controllable structures and free –NH2groups via ROMP.Keywords:ROMP;poly(norbornene-methylamine);controllable;living polymerization;chitosan
研究领域:
高分子化学
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生物材料科学
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产品关联
DOI
PubMed
高影响因子
MACROMOLECULES
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2018
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IF 5.914
Zhitao Hu,Yi Chen,Huahua Huang,Lixin Liu,Yongming Chen
This article demonstrates the synthesis of a new kind of cationic poly(δ-valerolactone) with primary amino groups at α-positions (poly(α-NH2-VL)) via ring-opening polymerization (ROP) of α-NHBoc-valerolactone (α-NHB-VL) followed by a simple deprotection reaction. The ROP of α-NHB-VL using benzyl alcohol as an initiator and DBU/TU (1,8-diazabicyclo[5.4.0]undec-7-ene/thiourea) as a catalytic system in THF at room temperature afforded poly(α-NHB-VL) with narrow molecular weight distribution. The 1H NMR and MALDI-TOF MS analysis of poly(α-NHB-VL) indicated that each polymeric chain was capped by the initiator. Kinetic experiments confirmed the living nature of the DBU/TU-catalyzed ROP of α-NHB-VL in THF. The copolymerization result indicated that the polymerization activity of α-NHB-VL is comparable to that of ε-caprolactone (CL) and VL. In addition, block copolymers containing poly(α-NHB-VL) were successfully synthesized regardless of whether hydrophilic PEG or hydrophobic PCL was used as the macroinitiator. Moreover, water-soluble poly(α-NH2-VL) was obtained by treatment with trifluoroacetic acid (TFA). It was found that poly(α-NH2-VL) degraded more slowly at pH 5.5 than at pH 7.4 through a hydrolysis kinetics study.
研究领域:
高分子化学
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材料科学
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生物医学工程
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DOI
高影响因子
SENSORS AND ACTUATORS B-CHEMICAL
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2015
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IF 4.097
Zhu Yu,Zaiwen Tian,Zhengqian Li,Zaoli Luo,Yan Li,Yi Li,Jun Ren
In this paper, a thioacetal chemosensor 1 incorporating simultaneously a carbazole moiety and an azobenzene moiety was synthesized. Among other metal ions , Hg 2+ proved to be able to selectively induce both color and fluorescence changes of 1 . The mechanism of Hg 2+ -promoted cleavage of thioacetal was confirmed by 1 H NMR experiments. Upon the addition of Hg 2+ into the yellow CH 3 CN/H 2 O solution of 1 , the resultant azobenzene-containing thioglycolamide was precipitated from the solution as a mercuric salt, leading to a colorless solution. Therefore, a novel color change pattern was developed.
研究领域:
分析化学
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环境科学
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材料科学
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DOI
高影响因子
JOURNAL OF POLYMER RESEARCH
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2018
·Vol. 26
·期 1
·1-6
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IF 1.434
Liang HuaQing,Li Sihan,Liu Dong,Liu Yijun,Long YongJiang,Liang GuoDong,Zhu FangMing
Herein, we demonstrated the synthesis and characterization of a well-defined diblock copolymer consisting of isotactic poly( p -hydroxystyrene) ( i P( p -HOS)) and 1,4- trans -polybutadiene (1,4- trans -PBD), i P( p -HOS)- b -1, 4- trans -PBD, by the combination of sequential monomer addition and deprotection. Isospecific living polymerization of p - tert - butyldimethylsilyloxystyrene and living trans -1,4-polymerization of 1,3-butadiene were catalyzed by 1, 4-dithiabutandiyl-2, 2ʹ-bis(6-cumenyl-4-methylphenoxy) titanium dichloride (complex 1) activated by methylaluminoxane (MAO) at room temperature to provide highly stereospecific isotactic poly( p - tert -butyldimethylsilyloxystyrene) ( i P( p -TBDMSOS)) and 1,4- trans -polybutadiene (1,4- trans -PBD) with narrow molecular weight distribution. Furthermore, the i P( p -TBDMSOS)- b -1, 4- trans -PBD was prepared via sequential monomer addition in the presence of complex 1 and MAO. The deprotection of the i P( p -TBDMSOS) block was promoted by concentrated hydrochloric acid to produce i P( p -HOS)- b -1, 4- trans -PBD. In addition, the resultant diblock copolymer and intermediate polymers were characterized by gel permeation chromatography, nuclear magnetic resonance and differential scanning calorimeter.
研究领域:
高分子化学
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材料科学
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产品关联
DOI
高影响因子
JOURNAL OF POLYMER RESEARCH
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2017
·Vol. 24
·期 4
·1-7
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IF 1.615
Li Hu,Zhou Zhen,Liu Jingcheng,Zheng Xiangfei,Xu Wenjia,Ji Changwei,Shi Weidong,Liu Ren,Liu Xiaoya
Hexakis(4-formylphenoxy) cyclotriphosphazene (HAPCP), substitution reaction product of hexachlorotriphosphazene (HCTP) with p-hydroxybenzaldehyde, was reduced by sodium borohydride to afford hexakis[4-(hydroxymethyl) phenoxyl] cyclotriphosphazene (HHPCP). The hydroxyl group of this compound was then protected by the reaction with di-tert-butyl dicarbonate ester (DBDC) in the presence of 4-dimethylaminopyridine (DMAP) as catalyst to give t-butyloxy carbonyl (tBOC) protected HHPCP. Fourier-transform infrared spectroscopy (FT-IR) and proton nuclear magnetic resonance ( 1 H NMR) were employed to characterize the chemical structure, indicating that the synthesis was successful. Thermal behavior was characterized by thermogravimetric analysis (TGA), the results showed that the initial thermal decomposition temperature occurred at approximately 170 °C, X-ray diffraction analysis (XRD) results showed that the tBOC protected HHPCP derivatives had amorphous form, and performed excellent film-forming property. Upon irradiation to 365 nm exposure, the photoacid generated proton H + , which can catalyze the deprotection of acid labile tBOC group. This type of novel molecular glass photoresist based on hexachlorotriphosphazene showed high sensitivity, making it possible to fabricate 1 μm line and space pattern under i-line exposure.
研究领域:
材料科学
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化学
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半导体制造
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DOI
高影响因子
JOURNAL OF MOLECULAR LIQUIDS
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2024
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IF 5.3
Ao Gao,Wei Lu,Yuntao Liang,Zhenglong He,Jinliang Li,Yong Sun,Shuanglin Song,Xinfeng Cui,Xiang Gao
In this study, pH responsiveness of 1, 1, 1, 3, 3, 3-hexamethyldisilazane terminated m-Cresol (HTMC) in different-rank coals was investigated, and its inhibition performance regarding the spontaneous combustion of coal was explored. First, color changes in the deprotection reaction of HTMC under different acidic conditions were analyzed. Then, surface microstructures of these coals and pH values of their filtrates were tested. Subsequently, experiments were performed on different coal samples for grasping their low-temperature oxidation characteristics, weight loss rates, pore characteristics, and free radical variations. The experimental results show that HTMC can effectively protect phenolic hydroxyl groups in inhibitors, and the acidity of coal can promote the conversion rate of its deprotection reaction. For instance, in XAM coal (pH ≈ 6), sufficient H + stimulates HTMC to release massive m-Cresol which contains highly reactive phenolic hydroxyl, thereby effectively suppressing increases of the concentration and type of free radicals. The crossing point temperature (177.2 °C) and inhibition rate at 110 °C (75.9 %) of the HTMC-inhibited XAM sample are 33.1 °C and 17.9 % higher than those of the m-Cresol-inhibited one, respectively. This study confirms the applicability of pH-responsive HTMC to different-rank coals and may lay a theoretical foundation for the design of efficient reactive inhibitors.
研究领域:
化学工程
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煤科学
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材料科学
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产品关联
DOI
高影响因子
International Journal of Polymeric Materials and Polymeric Biomaterials
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2022
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IF 3.221
Zhao Wang,Wenli Song,Ruilong Sheng,Xinyu Guo,Lingyun Hao,Xiaojuan Zhang
A new series of cholesterol-bearing poly(methacrylate)s with pendant cationic (l-)-lysine (Chol-PHML) was synthesized via reversible addition–fragmentation chain transfer (RAFT) polymerization, followed by Boc-deprotection. Their structures were characterized by nuclear magnetic resonance (NMR) spectroscopy and gel permeation chromatography (GPC). Then, the average particle sizes and zeta potentials of the Chol-PHML/pDNA polyplexes were examined using dynamic light scattering (DLS), and their plasmid DNA (pDNA)-binding ability was analyzed using agarose gel retardation assay. In vitro cytotoxicity of the polycations was determined using a cell counting kit-8 (CCK-8) assay and lactate dehydrogenase (LDH) kits in HeLa cells. The polyplex’s gene transfection effectiveness was investigated using a luciferase assay. The results revealed that the Chol-PHML series could efficiently bind/load pDNA with a high binding affinity (N/P < 3.0) and subsequently form nanoparticles with the sizes of 90–200 nm and zeta potentials of ∼+40 mV in an aqueous solution. The in vitro cytotoxicity and gene transfection efficiency considerably depended on the Chol-PHML vector’s molecular weight. The optimal Chol-PHML27 exhibited a substantially higher gene transfection efficiency and lower cytotoxicity than those of the linear structural PLL (15 K–30K) and PHML26 control. This study presents a simple method for synthesizing biocompatible and controllable cationic gene vectors by introducing hydrophobic cholesterol moieties, which will function as a promising foundation for gene delivery.
研究领域:
高分子化学
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基因治疗
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生物医学工程
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分子生物学
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产品关联
DOI
高影响因子
危险品化学品经营许可证（带存储）