ORGANOMETALLICS
·
2020
·
IF 3.804
Liangwei Zhang,Long Liu,Tianzeng Huang,Qizhi Dong,Tieqiao Chen
A palladium-catalyzed cyclobutanation of aryl sulfonates with strained alkenes has been developed. The methodology is featured to achieve the cleavage of both C–O and C–H bonds of phenol derivatives in one pot. Under the reaction conditions, in addition to reactive triflates, the relatively inactive tosylates and mesylates can also be transformed into the corresponding benzocyclobutanes in high yields. This reaction can be carried out in gram-scale experiments with a low loading of the palladium catalyst and is applicable to the cyclobutanative modification of bioactive molecules, highlighting its synthetic value in organic synthesis.
研究领域:
有机化学
·
催化化学
·
合成化学
✓ 已验证
DOI
高影响因子
DESALINATION
·
2023
·
IF 9.9
Zhongyang Wang,Muhammad Adnan Akram,Shanshan Zhang,Jingwei Gong,Lihua Zhao,Zhiyu Liu,Q. Jason Niu
The typical “ridge-valley” structure of traditional reverse osmosis (RO) membranes ensures good permeability with high risk of inducing membrane fouling . It is a challenge to develop a smooth RO membrane without loss of permeability. In this study, cyclobutane-1,2,3,4-tetracarbohydrazide (CBTH) was designed and synthesized, and a composite RO membrane based on CBTH and cyclobutane-1,2,3,4-tetracarboxylic acid chloride (BTC) was constructed. The CBTH-BTC membrane exhibits a smooth selective layer with thickness of 45 nm. The desalination performance test results show that the CBTH-BTC membrane has permeability and desalination performance comparable to the traditional RO membrane (the water permeability coefficient reaches 3.0 L·m −2 ·h −1 ·bar −1 , and the rejection of NaCl reaches 99.2 %). Importantly, the hydrophilic and smooth surface imparts the membrane with good antifouling properties to hydrophilic, hydrophobic and surfactant pollutants. In this study, RO membranes with good permeability and excellent antifouling performance were successfully prepared from the perspective of reaction monomer design, which provides a new idea to regulate the morphology and antifouling properties of RO membranes.
研究领域:
材料科学
·
化学工程
·
环境科学
✓ 已验证
产品关联
DOI
高影响因子
ADVANCES IN POLYMER TECHNOLOGY
·
2020
·
IF 1.539
Baihong Chi,Mengying Wei,Yong He
A series of fluorine-containing polyacrylic epoxy (FPAE) prepolymers with different fluorine content and molecular weight are synthesized by solution free radical polymerization of hexafluorobutyl methacrylate (HFBMA), butyl acrylate (BA), and glycidyl methacrylate (GMA). The synthesized prepolymers show high conversion and low volume shrinkage. The effect of different types of active diluent for the cationic UV curing of FPAE was investigated, among which oxetane exhibits better comprehensive property than epoxy and vinyl ether. The formulations with the optimal ratio of different functionality oxetane combination show good flexibility, adhesion, hydrophobicity, and antistain property.
研究领域:
材料科学
·
化学工程
✓ 已验证
产品关联
DOI
高影响因子
INDUSTRIAL & ENGINEERING CHEMISTRY RESEARCH
·
2018
·
IF 3.141
Wenhua Xu,Yuanhai Su,Yang Song,Minjing Shang,Li Zha,Qinghua Lu
Cyclobutanetetracarboxylic dianhydride (CBDA) was prepared by photodimerization of maleic anhydride in capillary microreactors within Taylor flow under UV irradiation. Both inert gas and ultrasound were introduced into this photochemical process to avoid the potential channel clogging resulting from the CBDA deposition. Higher input power of the Hg lamp, lower reactant concentration, longer residence time, and smaller inner diameter of the capillary were found to result in higher CBDA yield. The yield of CBDA could reach as high as 66.3% at an actual residence time of 30 min in the capillary microreactor with 0.5 mm inner diameter. According to the analysis of energy conversion, only low effective photoelectric transformation efficiencies could be achieved in this photochemical process. However, the photonic efficiency for this photodimerization carried out in capillary photomicroreactors was much higher compared to batch photoreactors and was comparable with that for other photochemical transformations using similar photomicroreactors and light sources.
研究领域:
化学工程
·
光化学
✓ 已验证
产品关联
DOI
高影响因子
ELECTROCHIMICA ACTA
·
2017
·
IF 4.798
Kang Ma,Qian Tang,Chun-rong Zhu,Jun-fei Long,Cheng-bin Gong,Xiang-kai Fu
This work reports novel dual-colored and fast switching electrochromic materials based on pyridinium salts , 1,1′,1″,1‴-tetrakis(4,4′,4″,4‴-tetrapyridyl)cyclobutane derivatives (TPCBDs). TPCBDs show outstanding electrochromic properties including fast electrochromic switching, dual color, reasonable contrast, low driving voltage, and good stability. TPCBDs are promising candidates for visible electrochromic displays because of their remarkable electrochromic behaviors.
研究领域:
材料科学
·
电化学
✓ 已验证
DOI
高影响因子
THERMOCHIMICA ACTA
·
2022
·
IF 3.378
Jilei Xu,Ping Chen,Shuaijiang Ma,Guohao Zhu,Lihao Wu
In this work, three bismaleimides containing cardo and ortho -oxazine structures, with dual advantages of bismaleimide and benzoxazine resin, were synthesized. Their chemical structures were characterized by Fourier transform infrared (FT-IR) spectroscopy and nuclear magnetic resonance (NMR) spectroscopy. The kinetics of curing and kinetic model were investigated by non-isothermal differential scanning calorimetry. The curing reaction of the bismaleimide was studied by in-situ FT-IR spectroscopy. Studies showed that both bismaleimide and benzoxazine provided the new structure with better thermal stability and solubility, compared to similar type of materials and commercial bismaleimides. Additionally, the further thermal rearrangement of the internal structure of the polymer at high temperature formed a benzoxazole structure with higher thermal stability. The rearrangement due to thermal changes was confirmed by in-situ FT-IR and solid-state 13 C-NMR spectroscopy. Microscale combustion calorimetry (MCC) showed that both, bismaleimide and benzoxazole resins, were formed after thermal rearrangement and had excellent flame-retardant properties.
研究领域:
材料科学
·
高分子化学
✓ 已验证
产品关联
DOI
高影响因子
MATERIALS SCIENCE-POLAND
·
2021
·Vol. 39
·期 3
·371-382
·
IF 1.022
Cheng Chen,Bi-Wu Huang,Zheng-Ting Lu,Yang Wu
Precursor 3-ethyl-3-hydroxymethyloxetane was synthesized with trihydroxypropane and diethyl carbonate as the main raw materials. Intermediate 3-ethyl-3-allylmethoxyoxetane was synthesized with 3-ethyl-3-hydroxymethyloxetane and allyl bromide. Prepolymer 1,3-bis[(3-ethyl-3-methoxyoxetane)propyl]tetramethyldisiloxane was synthesized with 3-ethyl-3-allylmethoxyoxetane and 1,1,3,3-tetramethyldisiloxane. Cationic photoinitiator triarylsulfonium hexafluoroantimonate of 3 wt% was added to the prepolymer, and a novel kind of photosensitive resin was prepared. Structures of the compounds obtained at individual stages of the synthesis were analyzed and characterized by FTIR and 1H-NMR. Photo-DSC analysis showed that the prepolymer had excellent photosensitivity. Thermogravimetric analysis (TG) revealed that the ultraviolet (UV)-cured samples owned excellent thermal stabilities of up to 405°C. And the mechanical properties of the UV-cured samples were tested by the universal material testing machine, giving 25.95 MPa of tensile strength, 2,935.15 MPa of elastic modulus, and 4.09% of elongation at break.
研究领域:
高分子科学
·
材料科学
·
化学工程
✓ 已验证
DOI
高影响因子
Journal of Flow Chemistry
·
2022
·Vol. 12
·期 1
·91-100
·
IF 3.264
Xu Wenhua,Pan Yizhe,Chen Liuyang,Su Yuanhai,Shang Minjing,Lu Xuemin,Lu Qinghua
The combination of continuous-flow microreactors and photoreaction is one of the important researches in flow chemistry. Dimethyl-substituted cyclobutanetetracarboxylic dianhydride (DM-CBDA) was prepared through photodimerization in photomicroreactors and applied in the preparation of polyimide films. It was found that ethyl acetate as the solvent and an appropriate concentration of substrate could benefit this photodimerization process in the capillary photomicroreactor. Higher photonic efficiency and higher DM-CBDA yield were obtained in the photomicroreactor as compared to batch photoreactors. DM-CBDA was applied to prepare the colorless transparent polyimide films, which showed a high polymerization activity for the preparation of poly(amic acid) with high molecular weight. A PI film of DM-CBDA/ODA with the UV cutoff wavelength of 295 nm, the glass transition temperature of 376 °C, and the elongation at break of 11.3% was prepared. This work broadens the application of photomicroreactors for the preparation of polyimide monomers in flow chemistry and its films with good transparent, thermal and mechanical properties.
研究领域:
材料化学
·
高分子科学
✓ 已验证
产品关联
DOI
高影响因子
ACS Sustainable Chemistry & Engineering
·
2024
·
IF 7.1
Jun Zhang,Xiu-tian-feng E,Bo Yang,Xiumei Ma,Xueping Wang,Ninghui Chang,Qiuyu Zhang,Ji-Jun Zou,Junjian Xie
High-energy-density cyclobutane fuels were directly synthesized via room-temperature-integrated one-pot two-step oxidation/self-photosensitized [2 + 2] cycloaddition using lignocellulose-derived cyclic ketones and cyclic alcohols for the first time, which endow much higher density, lower freezing point, and higher neat heat of combustion than other biofuels achieved from the same feedstocks and hence denote a new kind of sustainable high-density fuels appealing for practical applications.
研究领域:
有机化学
·
可再生能源
·
生物燃料开发
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF POLYMER SCIENCE PART A-POLYMER CHEMISTRY
·
2017
·Vol. 55
·期 11
·1920-1928
·
IF 2.952
Yawen Huang,Shengbo Zhang,Huan Hu,Xiaonan Wei,Hongtao Yu,Junxiao Yang
Low dielectric photopatternable materials have aroused much interest owing to their potential application as alternatives of conventional photoresists. Although a number of photosensitive groups have been established to construct photopatternable materials for many years, it is still a challenge to introduce them into polymer chains via a facile and control polymerization technique, such as living free radical polymerization. In this work, on the basis of the photoactive silaycyclobutene moiety, a new monomer, 1-methyl-1-(4-vinylphenyl) silacyclobutane (1-MVPSCB), was synthesized and demonstrated successful to conduct atom transfer radical polymerization (ATRP). Subsequently, the copolymerization of 1-MVPSCB with 4-vinylbenzocyclobutene (4-VBCB) and styrene produced a kind of benzocyclobutene/silacyclobutane double-crosslinked polymer (BS-DCP) with controlled benzocyclobutene/silacyclobutane ratios and low polydispersity index. Owing to the UV/thermally dual crosslinked structure, BS-DCP possesses photapatternability, high dimensional stability and low dielectric constant (2.37 at 10 MHz). These properties make BS-DCP a potential photoresist that could be directly used as interconnected dielectrics. © 2017 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2017 , 55 , 1920–1928
研究领域:
材料科学
·
聚合物化学
✓ 已验证
产品关联
DOI
高影响因子
ANALYTICAL CHEMISTRY
·
2019
·
IF 6.35
Ning Zhang,Wenchao Deng,Yao Li,Yangde Ma,Yan Liu,Xiangjun Li,Hailin Wang
Cyclobutane pyrimidine dimers (CPDs) and pyrimidine (6–4) pyrimidone photoproducts (6–4PPs) are genotoxic DNA lesions and mainly generated on thymine–thymine (T–T) dinucleotides upon UV irradiation. Regarding the sensitivity, specificity, and accuracy of analytical methods, it is of first choice to develop a reliable assay for simultaneous detection of these DNA lesions using liquid chromatography-tandem mass spectrometry (LC-MS/MS). However, the dilemma is the low detection sensitivity of the phosphate-containing dimeric photoproducts even using most favorable negative-ion mode for LC-MS/MS analysis. Unexpectedly, we observed that the detection sensitivity of T–T CPD and 6–4PP could be significantly improved using formic acid/acetic acid (∼ppm) as an additive of the mobile phase for reversed-phase LC-MS/MS analysis. This is the first demonstration of the enhancement of LC-MS/MS signals by formic acid/acetic acid in negative-ion mode. Of note, these acidic agents are often used for positive-ion mode in LC-MS assays. Benefited from the developed method, we could quantify both T–T CPD and 6–4PP in mouse embryonic stem cells upon UVC irradiation at low dosage. This sensitive method is applicable to the screening and identification of genes involved in formation, signaling, and repair of UV lesion.
研究领域:
生物化学
·
分子生物学
·
分析化学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
Nature Communications
·
2024
·Vol. 15
·期 1
·1-13
·
IF 14.7
Yang Chengshuai,Wang Yan,Su Zhen,Xiong Lunyi,Wang Pingping,Lei Wen,Yan Xing,Ma Dawei,Zhao Guoping,Zhou Zhihua
Taxol is a widely-applied anticancer drug that inhibits microtubule dynamics in actively replicating cells. Although a minimum 19-step biosynthetic pathway has been proposed and 16 enzymes likely involved have been characterized, stepwise biosynthetic reactions from the well-characterized di-oxygenated taxoids to Taxol tetracyclic core skeleton are yet to be elucidated. Here, we uncover the biosynthetic pathways for a few tri-oxygenated taxoids via confirming the critical reaction order of the second and third hydroxylation steps, unearth a taxoid 9 α -hydroxylase catalyzing the fourth hydroxylation, and identify CYP725A55 catalyzing the oxetane ester formation via a cascade oxidation-concerted acyl rearrangement mechanism. After identifying a acetyltransferase catalyzing the formation of C7-OAc, the pathway producing the highly-oxygenated 1 β -dehydroxybaccatin VI with the Taxol tetracyclic core skeleton is elucidated and its complete biosynthesis from taxa-4(20),11(12)-diene-5 α -ol is achieved in an engineered yeast. These systematic studies lay the foundation for the complete elucidation of the biosynthetic pathway of Taxol.
研究领域:
药理学
·
生物化学
·
分子生物学
·
生物技术
✓ 已验证
产品关联
DOI
PubMed
高影响因子
危险品化学品经营许可证（带存储）