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
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
The evolution of the universe from the particle to the thinking organism has taken place through self-organization. Chemistry has a major role to play in understanding these processes leading to the generation of complex matter. Chemistry has developed a highly powerful molecularsyntheticchemistry, mastering the combination and recombination of atoms into increasingly complex molecules through selective chemical reactions. Supramolecular chemistry is harnessing intermolecular forces for the generation of informed supramolecular systems and processes through supramolecularsyntheticchemistry implementing molecular information carried by electromagnetic interactions. Supramolecular chemistry has been actively exploring systems undergoing self-organization, i.e., systems capable of spontaneously generating well-defined functional supramolecular architectures by self-assembly from their components, under the control of interactionalmolecularrecognition events, thus behaving as programmedchemicalsystems. Molecular chemistry may similarly take advantage of the selectivity of covalent reactions to assemble complex molecular architectures through self-organization processes implementing functionalmolecularrecognition. Supramolecular/non-covalent and molecular/covalent SELF-ORGANIZATION may thus be considered as the ULTIMATE SYNTHETIC CHEMISTRY, whereby chemical objects at both levels are generated on the basis of recognition processes involving either interactional or reactional features. Illustrations from the supramolecular domain will serve as illustrations. Supramolecular entities as well as molecules containing reversible bonds are able to undergo a continuous change in constitution by reorganization and exchange of building blocks. This capability defines a Constitutional Dynamic Chemistry (CDC) on both the molecular and supramolecular levels. CDC introduces a paradigm shift with respect to constitutionally static chemistry. It takes advantage of dynamic constitutional diversity to allow variation and selection and thus leads towards the emergence of adaptive and evolutive chemistry. 相似文献
The X‐ray crystal structures of the polyfluorinated complexes [5,5′‐bis(HCF2CF2CF2CF2CH2OCH2)‐2,2′‐bpy]MI2 ( 55‐8F‐PtI 2 and 55‐8F‐PdI 2 where M = Pt and Pd, respectively) were obtained. These two structures are found to show not only two different types of intramolecular, six‐membered cyclic C–H···F–C interactions (F2C–H···F–C and HC–H···F–C) as important structural features but also alternating fluorinated and non‐fluorinated layers. The F2C–H···F–C interactions, which are close to the metal core, are much better structurally characterized in this type of complexes with fluorous ponytails at the 5,5′ positions than those previously reported at the 4,4′ positions. The molecular planes of (bpy)MI2 are extended by self‐matching, using two C–H···I hydrogen bonds and one C–H···F–C blue‐shifting hydrogen bond. The F2C–H···F–C hydrogen bonds interact at the supramolecular level such that one polyfluorinated ponytail of the title compounds is transoid without an intramolecular C–H···F–C interaction, while the other polyfluorinated ponytail is cisoid with an intramolecular C–H···F–C interaction. Why one ponytail is cisoidal while the other is transoidal will be explained. Furthermore, the second type of C–H···F–C interactions involving the methylene H atom has been identified for the first time. In addition, these two metal structures are studied by density functional theory (DFT). 相似文献
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
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.
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
The general species (2,2′‐bpy)MX2 (M = Pd, Pt; X = Br, I) in a crystallization process results in an isomorphous convergence in P21/c. Yet, with polyfluorinated side chains, the general [5,5′‐(HCF2CF2CH2OCH2)2‐2,2′‐bpy]MX2 species proceeds to crystallize the isomorphous structures of 5 (M = Pt; X = I) and 6 (M = Pd; X = I) in P21/c only; structure 7 (M = Pt; X = Br) crystallizes in P21/c but is not isomorphous with 5 and 6 , and structure 8 (M = Pd; X = Br) forms differently in P–1. The causes making the system nonlinear are (1) the intramolecular CF2─H…X(─M) hydrogen bonds found in 5–7 but not in 8, and (2) in response to the transition from I to Br, bifurcated [C─H…]2F ─C hydrogen bonds that are formed in 5 and 6 and bifurcated C─ H […F─C]2 hydrogen bonds in 7 . Additionally, the intramolecular CF2─H…X(─M) hydrogen bonding from compounds 5–7 could be affirmed by the IR studies. 相似文献
Allosteric synthetic receptors are difficult to access by design. Herein we report a dynamic combinatorial strategy towards such systems based on the simultaneous use of two different templates. Through a process of simultaneous casting (the assembly of a library member around a template) and molding (the assembly of a library member inside the binding pocket of a template), a Russian‐doll‐like termolecular complex was obtained with remarkable selectivity. Analysis of the stepwise formation of the complex indicates that binding of the two partners by the central macrocycle exhibits significant positive cooperativity. Such allosteric systems represent hubs that may have considerable potential in systems chemistry. 相似文献