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91.
92.
Dr. Yifan Gu Prof. Jia-Jia Zheng Prof. Ken-ichi Otake Prof. Kunihisa Sugimoto Prof. Nobuhiko Hosono Prof. Shigeyoshi Sakaki Prof. Fengting Li Prof. Susumu Kitagawa 《Angewandte Chemie (Weinheim an der Bergstrasse, Germany)》2020,132(36):15647-15651
To achieve unique molecular-recognition patterns, a rational control of the flexibility of porous coordination polymers (PCPs) is highly sought, but it remains elusive. From a thermodynamic perspective, the competitive relationship between the structural deformation energy (Edef) of soft PCPs and the guest interaction is key for selective a guest-triggered structural-transformation behavior. Therefore, it is vital to investigate and control Edef to regulate this competition for flexibility control. Driven by these theoretical insights, we demonstrate an Edef-modulation strategy via encoding inter-framework hydrogen bonds into a soft PCP with an interpenetrated structure. As a proof of this concept, the enhanced Edef of PCP enables a selective gate-opening behavior toward CHCl3 over CH2Cl2 by changing the adsorption-energy landscape of the compounds. This study provides a new direction for the design of functional soft porous materials. 相似文献
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94.
95.
In this work, a vanillin complex is immobilized onto MCM-41 and characterized by FT-IR, X-ray diffraction, scanning electron microscopy, energy dispersive spectroscopy, thermogravimetric analysis, and BET techniques. This supported Schiff base complex was found to be an efficient and recoverable catalyst for the chemoselective oxidation of sulfides into sulfoxides and thiols into their corresponding disulfides (using hydrogen peroxide as a green oxidant) and also a suitable catalyst for the preparation of 2,3-dihydroquinazolin-4(1H)-one derivatives in water at 90°C. Using this protocol, we show that a variety of disulfides, sulfoxides, and 2,3-dihydroquinazolin-4(1H)-one derivatives can be synthesized in green conditions. The catalyst can be recovered and recycled for further reactions without appreciable loss of catalytic performance. 相似文献
96.
A greener and efficient method for the synthesis of ynones and 1,3-diynes using copper oxide nanoparticles (CuONPs) doped reduced graphene oxide (CuO@rGO) catalyst under palladium, ligand and solvent free conditions have been developed. The catalyst was subsequently utilized for the synthesis of biologically active 1,5-benzodiazepines in one pot via sequential addition of acyl chlorides, terminal alkynes and o-phenylenediamines. The methodology initially involves in situ formation of ynones which react with o-phenylenediamines in presence of ethanol to afford a wide variety of benzodiazepines. Mild reaction conditions, good to an excellent yield of the products, cheap and recyclable catalyst make this methodology environmentally benign and sustainable. 相似文献
97.
《Macromolecular bioscience》2018,18(3)
Despite great progress, it is still of high interest to explore new homogeneous assays for simple, visual, and selective protein detection. Herein, one new colorimetric sensor has been developed for visual detection of protein by using polymeric micelles as a sensing scaffold and the molecular recognition between protein and the ligand on the surface of the polymeric micelles as the driving force to trigger the readout of the detection signal. The polymeric micelles formed via the self‐assembly of the amphiphilic block polymer biotin‐labeled poly(ethylene glycol)‐block‐poly(3‐acryl aminophenylboronic acid) are endowed with colorful feature by incorporation of alizarin red S (ARS) into the hydrophobic core. Based on the response to streptavidin recognition, these micelles are further disintegrated through the competitive binding of α‐cyclodextrin with boronic acid for disassociation of ARS, which achieves orange–yellow to pink–purple transition in 2 h. This work will open the way to develop one new mix‐and‐measure, visual, and homogeneous assay. 相似文献
98.
Suresh P S Ravi Kumar Trivedi Nuggehally R. Srinivas Ramesh Mullangi 《Biomedical chromatography : BMC》2020,34(1):e4742
Quantitation of drugs used for the treatment of chronic lymphocytic leukemia in various biological matrices during both pre-clinical and clinical developments is very important, often in routine therapeutic drug monitoring. The first developed methods for quantitation were traditionally done on LC in combination with either UV or fluorescence detection. However, the emergence of LC with mass spectrometry in tandem in early 1990s has revolutionized the quantitation as it has provided better sensitivity and selectivity within a shorter run time; therefore it has become the choice of method for the analysis of various drugs. In this article, an overview of various bioanalytical methods (HPLC or LC–MS/MS) for the quantification of drugs for the treatment of chronic lymphocytic leukemia, along with applicability of these methods, is given. 相似文献
99.
Yuto Kurasaki Yasuhito Suzuki Akikazu Matsumoto 《Journal of polymer science. Part A, Polymer chemistry》2020,58(7):923-931
We carried out the thermal curing of the copolymers of N-allylmaleimide (AMI) and 2-ethylhexyl acrylate (2EHA) using 1,3,4,6-tetra(2-mercaproethyl)glycoluril ( G1 ), 1,3,4,6-tetra(3-mercaptopropyl)glycoluril ( G2 ), 1,3,4,6-tetraallylglycoluril ( G3 ), triallylisocyanurate (TAIC), and pentaerythritol tetrakis(3-mercaptobutyrate) (PEMB) as the crosslinkers. Based on the results for the analysis of thiol–ene reactions monitored by IR spectroscopy, it was confirmed that the curing rate significantly depended on the combination of the used crosslinkers. The insoluble fraction after curing was more than 90% for the systems using the glycoluril crosslinkers, while the conversion of the allyl groups was suppressed due to the rigid structure of these crosslinkers. The heat resistance and the mechanical properties of the crosslinked polymers were investigated by thermogravimetric analysis, differential scanning calorimetry, dynamic mechanical analysis, and mechanical tensile tests. For the products cured using the glycoluril crosslinkers, the glass transition temperature (Tg) and the maximum temperature of thermal decomposition (Tmax) were 54–59 °C and 395–409 °C, respectively, being higher than those for the cured product prepared with PEMB and TAIC as the conventional crosslinkers. The elasticity (75–139 MPa), the maximum strength (3.0–4.1 MPa), and the adhesion strength (6.7–10.7 MPa) for the polymers cured with the glycoluril crosslinkers, determined by the mechanical tensile and single lap-shear adhesion tests, were higher than those for cured materials produced with PEMB. Thus, the thermal and mechanical properties of the maleimide copolymers were efficiently enhanced by crosslinking using the rigid glycoluril compounds. © 2020 Wiley Periodicals, Inc. J. Polym. Sci. 2020 , 58, 923–931 相似文献
100.
Wenqing Zhang Dr. Jiuxing Li Prof. Dr. Bruno Salena Prof. Dr. Yingfu Li 《Chemistry (Weinheim an der Bergstrasse, Germany)》2020,26(3):592-596
DNA detection is usually conducted under nondenaturing conditions to favor the formation of Watson–Crick base-paring interactions. However, although such a setting is excellent for distinguishing a single-nucleotide polymorphism (SNP) within short DNA sequences (15–25 nucleotides), it does not offer a good solution to SNP detection within much longer sequences. Here we report on a new detection method capable of detecting SNP in a DNA sequence containing 35–90 nucleotides. This is achieved through incorporating into the recognition DNA sequence a previously discovered DNA molecule that forms a stable G-quadruplex in the presence of 7 molar urea, a known condition for denaturing DNA structures. The systems are configured to produce both colorimetric and fluorescent signals upon target binding. 相似文献