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排序方式: 共有234条查询结果,搜索用时 31 毫秒
81.
Berthet J Micheau JC Lokshin V Vales M Vermeersch G Delbaere S 《Organic letters》2008,10(17):3773-3776
The photochemical reactivity of the quinolinone 3 was investigated using NMR by monitoring its reactions under appropriate irradiation wavelengths. Besides the irreversible formation of degradation products which were structurally identified, the reversible formation of the enol 4 and cyclobutenol 5 was also observed. The enol and cyclobutenol can be switched or reversed back to the quinolinone 3, resulting in a photochromic three-state system in which the relative ratio of the three components largely depends on the irradiation wavelength used. 相似文献
82.
Carmen Villegas Aurel Diacon Thérèse Gorisse Lionel Derue Ingrid Freuze Magali Allain Hussein Awada Olivier Dautel Guillaume Wantz Piétrick Hudhomme 《Helvetica chimica acta》2023,106(6):e202300031
This study presents the synthesis and characterization of novel azido molecules with demonstrated crosslinking ability when used as additives in polymer/fullerene organic solar cells. These compounds derived from fullerenes C60 and C70, or dyes from perylenediimide, perylene and tetraphenylethylene frameworks, bearing a different number of azido groups, are of particular interest to stabilize and increase the thermal stability of the device morphology. In particular, the electro and photoactive dye derivatives allow the introduction of additional functionality with the possibility of extending the absorption domain of the photoactive layer. In addition, and more broadly, such azido crosslinkers could find applications in the field of optoelectronic devices as a simple and cheap strategy to improve the performance and long-term stability of organic solar cells, perovskites solar cells, or organic light-emitting diodes. 相似文献
83.
Synthesis and metal cation complexing properties of crown-annelated terthiophenes containing 3,4-ethylenedioxythiophene 总被引:1,自引:0,他引:1
Demeter D Blanchard P Allain M Grosu I Roncali J 《The Journal of organic chemistry》2007,72(14):5285-5290
Macrocyclic systems derived from crown-annelated terthiophene involving a median EDOT unit have been synthesized by coupling diiodooligooxyethylene chains and bis(2-cyanoethylsulfanyl)terthiophene under high dilution conditions. The metal cation complexing properties of the compounds have been analyzed using 1H NMR, UV-vis spectroscopy, and cyclic voltammetry. These various experiments provide consistent results showing that one of the compounds exhibits interesting complexing properties for Pb2+. 相似文献
84.
Magali Bardet Islam Boussaada A. Raouf Chouikha Jean-Marie Strelcyn 《Bulletin des Sciences Mathématiques》2011,(2):230-249
We study the isochronicity of centers at O∈R2 for systems where A,B∈R[x,y], which can be reduced to the Liénard type equation. When deg(A)?4 and deg(B)?4, using the so-called C-algorithm we found 36 new multiparameter families of isochronous centers. For a large class of isochronous centers we provide an explicit general formula for linearization. This paper is a direct continuation of a previous one with the same title [Islam Boussaada, A. Raouf Chouikha, Jean-Marie Strelcyn, Isochronicity conditions for some planar polynomial systems, Bull. Sci. Math. 135 (1) (2011) 89–112], but it can be read independently. 相似文献
85.
3-Alkoxy-4-cyanothiophenes are efficiently synthesized in two steps from the readily available 4-cyano-3-oxotetrahydrothiophene. Regioisomers of bithiophene derivatives are easily synthesized by playing on the strong electronic dissymmetry of the thiophene ring induced by the alkoxy and cyano groups. 相似文献
86.
Pezzini J Joucla G Gantier R Toueille M Lomenech AM Le Sénéchal C Garbay B Santarelli X Cabanne C 《Journal of chromatography. A》2011,1218(45):8197-8208
We evaluated mixed mode chromatography for the capture of recombinant antibodies from CHO cell culture supernatants. We studied PPA HyperCel, HEA HyperCel, MEP HyperCel and Capto adhere resins, which all contain hydrophobic and cationic groups. A microplate approach combined with DoE modeling allowed the exploration of the complex behaviors of these mixed mode resins. Optimal conditions for antibody purification and host cell proteins (HCPs) elimination were determined and then directly up-scaled to laboratory columns. Then we used mass spectrometry to identify the major HCPs potentially coeluted with the antibody. Differences between the four resins in terms of amount, complexity and identity of the HCPs present in the elution fractions were investigated. 相似文献
87.
Schulz J Vimont D Bordenave T James D Escudier JM Allard M Szlosek-Pinaud M Fouquet E 《Chemistry (Weinheim an der Bergstrasse, Germany)》2011,17(11):3096-3100
Take it eaSi! Nucleosides, dinucleotides, and one oligonucleotide, all modified by click chemistry, have for the first time been directly and very efficiently labeled with (18)F by using a silicon-based, one-step approach that opens the way for the development of a new class of positron emission tomography (PET) tracers (see graphic). 相似文献
88.
Claudia Virués Zaira Domínguez Magali Salas Rosa Elena Navarro Enrique F. Velázquez Samuel Cruz Javier Hernández Motomichi Inoue 《Journal of inclusion phenomena and macrocyclic chemistry》2012,74(1-4):407-413
Host?guest complexation has been studied by 1H NMR on the benzyl and phenethyl amides of ferulic and caffeic acids as the guests in chloroform and acetonitrile; the counter host is a cyclophane which integrates four phenylene rings, amino and amide groups in the macrocyclic framework and bears four pendant methyl acetate ester arms. CAPE, one of the best known natural antioxidants, also has been studied for comparison. Among the guests studied, ferulic acid benzyl amide shows NMR shifts due to the formation of a host?guest complex in chloroform. The complexation occurs in two steps with the formation constants K 1?=?[HG]/[H][G]?=?6?M?1 and β 2?=?[HG2]/[H][G]2?=?87?M?2. Two guest molecules are bound on the surface of the macrocyclic framework of a host molecule by two hydrogen bonds, NH(host amide)···O=C(guest amide) and C=O(host ester)···HO(guest phenol). The latter hydrogen bond may protect the bioactive site, i.e., phenol OH, of guest molecules captured in the complex against undesirable oxidation. This feature is observed only for ferulic acid benzyl amide in chloroform; the cyclophane ester interacts with this amide, distinctively from the other hydroxycinnamic acid derivatives. 相似文献
89.
Preparation of inorganic nanoparticles in oil-in-water microemulsions: A soft and versatile approach
Margarita Sanchez-Dominguez Kelly Pemartin Magali Boutonnet 《Current Opinion in Colloid & Interface Science》2012,17(5):297-305
In this review, the synthesis of inorganic nanoparticles using oil-in-water (O/W) microemulsions as confined reaction media is discussed. Synthesis using (O/W) microemulsions has been demonstrated for a great variety of inorganic nanoparticles: metallic (Pt, Pd, Rh, Ag), single metal oxides (CeO2, ZrO2, TiO2, Fe2O3), mixed and doped metal oxides (Ce0.5Zr0.5O2, Ce0.99Eu0.01O2, Zr0.99Eu0.01O2, and Fe2Mn0.5Zn0.5O4), semiconductors (PbS, CdS, Ag2S, ZnS, CdSe, PbSe, Ag2Se), fluorides (CaF2, YF3, NdF3, PrF3), phosphates (CePO4, HoPO4), and chromates (BaCrO4 and PbCrO4). There are two synthetic strategies: 1) the use of oil-in water (O/W) microemulsions, in which the precursor is an ionic salt which is dissolved in the continuous aqueous phase; and 2) use of O/W microemulsions, in which the precursor is an organometallic salt dissolved in the oil droplets of the microemulsion. The latter approach keeps more resemblance to the typical W/O microemulsion reaction method, as it has the greatest level of precursor confinement. 相似文献
90.
Alteration of enzyme activity and enantioselectivity by biomimetic encapsulation in silica particles
Emond S Guieysse D Lechevallier S Dexpert-Ghys J Monsan P Remaud-Siméon M 《Chemical communications (Cambridge, England)》2012,48(9):1314-1316
Direct encapsulation of esterase or lipase fused with the silica-precipitating R5 peptide from Cylindrotheca fusiformis in silica particles afforded high yields of active entrapped protein. The hydrolytic activity of both enzymes against p-nitrophenyl butyrate was similarly affected by encapsulation and the enantioselectivity of the esterase was both improved and inverted. 相似文献