共查询到20条相似文献,搜索用时 31 毫秒
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Sowmya Padejjar Vasantha Boja Poojary Revanasiddappa Bistuvalli Chandrashekarappa 《中国化学会会志》2019,66(6):638-650
In view of developing novel bioactive compounds, a series of 2‐(5‐[2‐methyl‐6‐arylpyridin‐3‐yl]‐1,3,4‐oxadiazol‐2‐ylthio)‐1‐arylethanones (6a–n) were designed and synthesized in good yield. Novel compounds were evaluated for their antibacterial and anti‐inflammatory activities. All synthesized compounds were screened for their antibacterial activity against Staphylococcus aureus, Bascillus subtilis, Eschericia coli, and Pseudomonas aeruginosa strains. Compounds 6a , 6b , 6c , 6h , and 6i displayed the highest antibacterial activity with minimal inhibitory concentration (MIC) values ranging from 6.25–12.5 μg/mL in comparison with the standard Ciprofloxacin. The results of anti‐inflammatory activity of carrageenan‐induced footpad edema assay indicated that tested compounds exhibited remarkable anti‐inflammatory activity with percentage of inhibition of 63.9–70.1% (potency 96.8–106.20% of indomethacin activity) after 3 hr. Particularly, 6c – e and 6j – l were found to be excellent inhibitors of inflammation, with potential higher than that of the standard, Indomethacin. 相似文献
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Bobby Happ Christian Friebe Andreas Winter Dr. Martin D. Hager Dr. Richard Hoogenboom Dr. Ulrich S. Schubert Prof. Dr. 《化学:亚洲杂志》2009,4(1):154-163
The synthesis of a variety of 2‐(1H‐1,2,3‐triazol‐4‐yl)‐pyridines by click chemistry is demonstrated to provide straightforward access to mono‐functionalized ligands. The ring‐opening polymerization of ε‐caprolactone initiated by such a mono‐functionalized ligand highlights the synthetic potential of this class of bidentate ligands with respect to polymer chemistry or the attachment onto surfaces and nanoparticles. The coordination to RuII ions results in homoleptic and heteroleptic complexes with the resultant photophysical and electrochemical properties strongly dependent on the number of these ligands attached to the RuII core. 相似文献
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Wei Zhang Wusong Jin Dr. Takanori Fukushima Dr. Noriyuki Ishii Dr. Takuzo Aida Prof. Dr. 《Angewandte Chemie (International ed. in English)》2009,48(26):4747-4750
The assembly line : Hexabenzocoronene amphiphiles appended with pyridyl‐terminated triethylene glycol side chains, in combination with trans‐[Pt(PhCN)2Cl2], lead to the formation of graphitic nanotubes. The structural features and dimensions of the nanotubes depend on the assembly conditions. A platinum(II)‐bridged cyclic dimer having two HBC units self‐assembles into a nanotubular structure.
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《中国化学会会志》2018,65(6):674-680
The feasibility of ultrafast high‐resolution intermolecular multiple‐quantum coherence (UF‐iMQC) spectroscopy for the direct analysis of molecular‐mobility‐restricted samples that are not suitable for magic‐angle spinning, such as a jelly, hand soap, and marrow, is presented. Most components could be directly detected in their original state within 1 min without the need for tedious sample preparation processes. When we use conventional liquid nuclear magnetic resonance (NMR) method to study these systems, the spectral information could not be retrieved owing to the intrinsic inhomogeneous magnetic fields caused by sample inhomogeneity. In addition, the possibility for UF‐iMQC‐based quantifications is shown. The examples presented in this paper demonstrate the potential of UF iMQC NMR for food safety inspection, for quality testing of daily‐life supplies, or in assisting medical diagnosis. 相似文献
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Well‐Defined Single‐Site Monohydride Silica‐Supported Zirconium from Azazirconacyclopropane 下载免费PDF全文
Bilel Hamzaoui Dr. Mohamad El Eter Dr. Edy Abou‐hamad Dr. Yin Chen Dr. Jérémie D. A. Pelletier Prof. Jean‐Marie Basset 《Chemistry (Weinheim an der Bergstrasse, Germany)》2015,21(11):4294-4299
The silica‐supported azazirconacyclopropane ?SiOZr(HNMe2)(η2‐NMeCH2)(NMe2) ( 1 ) leads exclusively under hydrogenolysis conditions (H2, 150 °C) to the single‐site monopodal monohydride silica‐supported zirconium species ?SiOZr(HNMe2)(NMe2)2H ( 2 ). Reactivity studies by contacting compound 2 with ethylene, hydrogen/ethylene, propene, or hydrogen/propene, at a temperature of 200 °C revealed alkene hydrogenation. 相似文献
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Sui‐Lung Yim Prof. Hak‐Fun Chow Prof. Man‐Chor Chan Prof. Chi‐Ming Che Dr. Kam‐Hung Low 《Chemistry (Weinheim an der Bergstrasse, Germany)》2013,19(7):2478-2486
A series of main‐chain poly(amide‐triazole)s were prepared by copper(I)‐catalyzed alkyne–azide AABB‐type copolymerizatons between five structurally similar diacetylenes 1 – 5 with the same diazide 6 . The acetylene units in monomers 1 – 5 possessed different degrees of conformational flexibility due to the different number of intramolecular hydrogen bonds built inside the monomer architecture. Our study showed that the conformational freedom of the monomer had a profound effect on the polymerization efficiency and the thermoreversible gelation properties of the resulting copolymers. Among all five diacetylene monomers, only the one, that is, 1 ‐Py(NH)2 which possesses the pyridine‐2,6‐dicarboxamide unit with two built‐in intramolecular H bonds could produce the corresponding poly(amide‐triazole) Poly‐(PyNH)2 with a significantly higher degree of polymerization (DP) than other monomers with a lesser number of intramolecular H bonds. In addition, it was found that only this polymer exhibited excellent thermoreversible gelation ability in aromatic solvents. A self‐assembling model of the organogelating polymer Poly‐(PyNH)2 was proposed based on FTIR spectroscopy, XRD, and SEM analyses, in which H bonding, π–π aromatic stacking, hydrophobic interactions, and the structural rigidity of the polymer backbone were identified as the main driving forces for the polymer self‐assembly process. 相似文献
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Xin‐Gui Li Prof. Dr. Hao Feng Mei‐Rong Huang Prof. 《Chemistry (Weinheim an der Bergstrasse, Germany)》2010,16(33):10113-10123
Poly[aniline(AN)‐co‐5‐sulfo‐2‐anisidine(SA)] nanograins with rough and porous structure demonstrate ultrastrong adsorption and highly efficient recovery of silver ions. The effects of five key factors—AN/SA ratio, AgI concentration, sorption time, ultrasonic treatment, and coexisting ions—on AgI adsorbability were optimized, and AN/SA (50/50) copolymer nanograins were found to exhibit much stronger AgI adsorption than polyaniline and all other reported sorbents. The maximal AgI sorption capacity of up to 2034 mg g?1 (18.86 mmol g?1) is the highest thus far and also much higher than the maximal Hg‐ion sorption capacity (10.28 mmol g?1). Especially at ≤2 mM AgI, the nanosorbents exhibit ≥99.98 % adsorptivity, and thus achieve almost complete AgI sorption. The sorption fits the Langmuir isotherm well and follows pseudo‐second‐order kinetics. Studies by IR, UV/Vis, X‐ray diffraction, polarizing microscopy, centrifugation, thermogravimetry, and conductivity techniques showed that AgI sorption occurs by a redox mechanism mainly involving reduction of AgI to separable silver nanocrystals, chelation between AgI and ? NH? /? N?/? NH2/ ? SO3H/? OCH3, and ion exchange between AgI and H+ on ? SO3?H+. Competitive sorption of AgI with coexisting Hg, Pb, Cu, Fe, Al, K, and Na ions was systematically investigated. In particular, the copolymer nanoparticles bearing many functional groups on their rough and porous surface can be directly used to recover and separate precious silver nanocrystals from practical AgI wastewaters containing Fe, Al, K, and Na ions from Kodak Studio. The nanograins have great application potential in the noble metals industry, resource reuse, wastewater treatment, and functional hybrid nanocomposites. 相似文献
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Thomas Biet Dr. Thomas Cauchy Dr. Narcis Avarvari 《Chemistry (Weinheim an der Bergstrasse, Germany)》2012,18(50):16097-16103
Two series of 4‐ and 5‐tetrathiafulvalenyl‐1,2,3‐triazoles, as multifunctional ligands and precursors for molecular materials, have been synthesized by copper‐ or ruthenium‐based “click” chemistry. The solid‐state structures of three ligands and two CuII complexes were determined. Large differences in the electron‐donating properties between the 1,4‐ and 1,5‐isomers were evidenced by cyclic voltammetry. Theoretical calculations support this observation and allow the assignment of the electronic transitions observed in UV/Vis spectra of the ligands. 相似文献
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Dr. Frédéric Niess Dr. Vincent Duplan Christian S. Diercks Prof. Jean‐Pierre Sauvage 《Chemistry (Weinheim an der Bergstrasse, Germany)》2015,21(41):14393-14400
Two large rings, 66‐ (m‐66 ) and 78‐membered ( m‐78 ) rings, each one incorporating two pairs of transition‐metal‐complexing units, have been prepared. The coordinating fragments are alternating bi‐ and tridentate chelating groups, namely, 2,9‐diphenyl‐1,10‐phenanthroline (dpp) and 2,2′,2′,6′′‐terpyridine (terpy) respectively. Both macrocycles form molecular figures‐of‐eight in the presence of FeII, affording a classical bis‐terpy complex as the central core. The larger m‐78 ring can accommodate a four‐coordinate CuI center with the formation of a {Cu(dpp)2}+ central complex and a highly twisted figure‐of‐eight backbone, whereas m‐66 is too small to coordinate CuI. Macrocycle m‐78 thus affords stable complexes with both FeII and CuI; the ligand around the metal changes from (terpy)2 to (dpp)2. This bimodal coordination situation allows for a large amplitude rearrangement of the organic backbone. When coordinated to preferentially octahedrally coordinated FeII or CuII, the height of the molecule along the coordinating axis of the tridentate terpy ligands is only about 11 Å, whereas the height of the molecule along the same vertical axis is several times as large for the tetrahedral CuI complex. Chemically or electrochemically driven contraction and extension motions along a defined axis make this figure‐of‐eight particularly promising as a new class of molecular machine prototype for use as a constitutive element in muscle‐like dynamic systems. 相似文献
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Prof. José Barluenga Dr. Agustín Jiménez‐Aquino Prof. Fernando Aznar Dr. Carlos Valdés 《Chemistry (Weinheim an der Bergstrasse, Germany)》2010,16(38):11707-11711
Regioselectively substituted indoles are prepared by a Pd‐catalyzed C? C/C? N bond‐forming sequence from imines and o‐dihaloarenes or o‐haloarene sulfonates. The heterogeneous reaction as a suspension in water and under microwave heating offers important advantages in comparison with the conventional reaction in an organic solvent, among them, operational simplicity, the employment of KOH solutions instead of alkoxides, and a dramatic reduction of reaction times. 相似文献
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Derrick A. Roberts Prof. Timothy W. Schmidt Prof. Maxwell J. Crossley Prof. Sébastien Perrier 《Chemistry (Weinheim an der Bergstrasse, Germany)》2013,19(38):12759-12770
The convergence of supramolecular chemistry and polymer science offers many powerful approaches for building functional nanostructures with well‐defined dynamic behaviour. Herein we report the efficient “click” synthesis and self‐assembly of AB2‐ and AB4‐type multitopic porphyrin–polymer conjugates (PPCs). PPCs were prepared using the copper(I)‐catalysed azide–alkyne cycloaddition (CuAAC) reaction, and consisted of linear polystyrene, poly(butyl acrylate), or poly(tert‐butyl acrylate) arms attached to a zinc(II) porphyrin core via triazole linkages. We exploit the presence of the triazole groups obtained from CuAAC coupling to direct the self‐assembly of the PPCs into short oligomers (2–6 units in length) via intermolecular porphyrinatozinc–triazole coordination. By altering the length and grafting density of the polymer arms, we demonstrate that the association constant of the porphyrinatozinc–triazole complex can be systematically tuned over two orders of magnitude. Self‐assembly of the PPCs also resulted in a 6 K increase in the glass transition temperature of the bulk material compared to a non‐assembling PPC. The modular synthesis and tunable self‐assembly of the triazole‐linked PPCs thus represents a powerful supramolecular platform for building functional nanostructured materials. 相似文献
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Andreas Fischer Daniel Stern Andrea Thorn Sascha Abraham Dietmar Stalke Uwe Klingebiel Prof. Dr. 《无机化学与普通化学杂志》2010,636(8):1527-1532
The lithium salt (HC–NCMe3)2SiFNLiR ( 1 ) R = C6H3(2,6‐CHMe2)2 reacts with trichlorogallium under displacement of the lithium ion by GaCl3 to give the adduct [(HC–NCMe3)2SiFN]– [(GaCl3)R·Li(thf)4]+ ( 1 ). Compound 1 thermally loses LiCl and forms the bicyclic ring intermediates V and VI . Compound VI adds the aniline H2NC6H3(2,6‐CHMe2)2 and the unsaturated, seven‐membered ring compound –NCMe3–CH2–CH=NCMe3GaCl2–NR–SiFNHR– ( 2 ) is obtained. The addition is accompanied by an enamine‐imine‐tautomerism and proves the Lewis acid character of the silicon atom in an unknown 3‐center‐2‐electron interaction of one nitrogen atom with the silicon and gallium atoms. Quantum chemical calculations of the thermal isomerisation process and crystal structures of 1 and 2 are reported. 相似文献
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Paolo Sanna Antonio Carta Laura Gherardini Mohammad Esmail Rahbar Nikookar 《ChemInform》2002,33(45):221-221
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Jesse J. Sabatini James M. Raab Ronald K. Hann Jr. Cathleen T. Freeman 《无机化学与普通化学杂志》2013,639(1):25-30
The development of barium‐free pyrotechnic illuminants is described. Heavy metal barium nitrate oxidizer and strontium nitrate oxidizer were replaced with sodium nitrate to adequately address environmental concerns while providing the brightest possible illuminant. The new formulations further address environmental concerns and mitigate single‐point‐of‐failure through the replacement of polyester‐based Laminac 4116/Lupersol binder system with the epoxy‐based Epon 813/Versamid 140 binder system. The new formulations were found to burn longer and brighter than the control with a low sensitivity to various ignition stimuli. 相似文献
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Xiaofen Chen Dr. Xiaofeng Liu Mark A. Burgers Dr. Ye Huang Prof. Dr. Guillermo C. Bazan 《Angewandte Chemie (International ed. in English)》2014,53(52):14378-14381
High‐efficiency bulk heterojunction (BHJ) organic solar cells with power conversion efficiencies of more than 5 % can be fabricated using the green solvent 2‐MeTHF. The active layers comprise a blend of a molecular semiconductor donor with intermediate dimensions (X2) and the soluble fullerene derivative [6,6]‐phenyl‐C61‐butyricacidoctylester (PC61BC8). A switch of the processing solvent from chloroform to 2‐MeTHF leads to no negative impacts on the morphology and charge‐transport properties of optimally performing BHJ films. Examinations by absorption spectroscopy, atomic force microscopy, and grazing incidence wide‐angle X‐ray scattering reveal no significant modification of morphology. These results show that green solvents can be excellent alternatives for large‐area printing of high‐performance organic photovoltaics (OPVs) and thus open new opportunities for sustainable mass production of organic solar cells and other optoelectronic devices. 相似文献
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Riccardo Salvio Sven Krabbenborg Wouter J. M. Naber Aldrik H. Velders David N. Reinhoudt Wilfred G. van der Wiel 《Chemistry (Weinheim an der Bergstrasse, Germany)》2009,15(33):8235-8240
The treatment of a suspension of graphite oxide (GO) with sodium azide leads to a material that, after reduction, features amino groups at the top and bottom of the sheets. These groups react through microcontact printing with an isothiocyanate monolayer on a silicon oxide substrate to form covalent bonds that strongly attach to the particles on the surface. With ultrasonication it is possible to obtain exfoliation of the sheets that are not covalently bound to the surface leaving single‐layer platelets attached to the substrate. The azido derivative can be also used to functionalize the graphene oxide with long alkylic chains through a click chemistry approach. This functionalization results in the exfoliation of this material in dimethylformamide. The novel materials were fully characterized by different techniques including IR spectroscopy, thermogravimetric analysis (TGA), scanning and transmission electron microscopy (SEM and TEM), X‐Ray photoelectron spectroscopy (XPS), and solid state NMR spectroscopy. The material with amino groups, after the reduction step, is conductive with a resistivity only approximately seven times larger than that of unprocessed graphite. This implies that after reduction of the GO, the conjugated sp2 network is largely restored. We consider this to be an important step towards a chemical approach for forming conducting large‐area platelet films of single‐layer graphene. 相似文献
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