19221-08-0Relevant academic research and scientific papers
Novel fluorescent liquid crystal containing azobenzene and stilbene moieties-synthesis, mesogenic and spectroscopic studies
Korbecka, Izabela,Jaworska, Joanna,Galewski, Zbigniew
, p. 166 - 168 (2017)
This paper presents synthesis and characterization of new rigid core dye composed of two chromophore moieties such as azobenzene and stilbene parts. During this study liquid-crystalline properties was investigated and found as expected. An additional and
Searching for new tools to counteract the helicobacter pylori resistance: The positive action of resveratrol derivatives
Di Fermo, Paola,Di Lodovico, Silvia,Amoroso, Rosa,De Filippis, Barbara,D’ercole, Simonetta,Di Campli, Emanuela,Cellini, Luigina,Di Giulio, Mara
, p. 1 - 16 (2020)
The drug-resistance phenomenon in Helicobacter pylori underlines the need of novel strategies to improve the eradication rate including alternative treatments combining antibiotic and non-antibiotic compounds with synergistic action. In this study, the antibacterial (MIC/MBC) and anti-virulence effects (biofilm reduction and swarming motility inhibition) of resveratrol-RSV and new synthetized RSV-phenol derivatives, with a higher bioavailability, alone and combined with levofloxacin-LVX were evaluated against resistant H. pylori clinical strains. The experiments were confirmed in vivo using the Galleria mellonella model. Among the studied RSV derivatives, RSV-3 and RSV-4 possessed higher antibacterial activity with respect to RSV (MICs from 6.25 to 200 μg/mL and from 3.12 to 200 μg/mL, respectively). RSV, RSV-3, and RSV-4 were able to synergize with LVX restoring its effect in two out of seven clinical resistant strains tested for the study. RSV, RSV-3, and RSV-4, alone and with LVX at sub-MIC and sub-synergistic concentrations, significantly reduced the biofilm formation. Moreover, RSV-3 and RSV-4 reduced the H. pylori swarming motility on soft agar. RSV, RSV-3, and RSV-4 were non-toxic for G. mellonella larvae and displayed a protective effect against H. pylori infection. Overall, RSV–phenol derivatives should be considered interesting candidates for innovative therapeutic schemes to tackle the H. pylori antibiotic resistance.
On the photophysical properties of a liquid crystal dimer based on 4-nitrostilbene: A combined experimental and theoretical study
Gak Simi?, Kristina,?or?evi?, Ivana,Janji?, Goran,Datz, Dániel,Tóth-Katona, Tibor,Tri?ovi?, Nemanja
, (2021)
A new liquid crystal dimer, 1,12-bis(4-(2-(4-nitrophenyl)ethenyl)phenoxy)dodecane, was synthesized and structurally characterized. The compound exhibited enantiotropic nematic phase. The spectroscopic properties were analysed by UV–Vis and fluorescence te
Styryl phenols, derivatives and their use in methods of analyte detection
-
, (2020/06/27)
Styryl compounds useful for preparing biological detections probes, and the use of the Styryl compounds for the detection, discrimination and quantification of biological targets.
Stilbene-benzophenone dyads for free radical initiating polymerization of methyl methacrylate under visible light irradiation
Qin, Xiaozhuan,Ding, Ge,Gong, Yulong,Jing, Chuan,Peng, Guangyue,Liu, Shihong,Niu, Lanying,Zhang, Shengtao,Luo, Ziping,Li, Hongru,Gao, Fang
, p. 27 - 40 (2016/05/09)
The AB and AB2 trans-stilbene-benzophenone dyads were synthesized through multi-step pathway. The target dyads showed remarkable absorption in visible light region. Visible light photoinitiating polymerization of methyl methacrylate by the new dyads was studied by photo-differential scanning calorimetry. The results suggested that the AB2 dyad showed more efficient photoinitiating polymerization of methyl methacrylate than the AB one under visible light irradiation. Furthermore, the new dyads yielded the greater visible light photoinitiaing polymerization effect than the intermolecular photoinitiating systems and the commercial photoinitiator titanocene respectively. The molecular weights of visible light photopolymers produced by the new dyads were determined by gel permeation chromatography. The visible light photoinitiating mechanism of the new dyads was analyzed by the static and transient absorption and emission spectra, electron spin resonance spectra and cyclic voltammograms. The thermal stabilities of the new dyads were further studied by differential scanning calorimetry and thermograving.
A simple protocol for the visual discrimination of natural cyclodextrins in aqueous solution using perichromic probes
Nandi, Leandro G.,Nicoleti, Celso R.,Stock, Rafaela I.,Barboza, Tainá A.,Andreaus, Jürgen,Machado, Vanderlei G.
, p. 1600 - 1606 (2015/02/19)
(Graph Presented) Three synthesized compounds, 4-(4-nitrostyryl)phenol, 2,6-dibromo-4-(2,4-dinitrobenzylideneamino) phenol and 2,6-dichloro-4-(2,4-dinitrobenzylideneamino)phenol, were deprotonated to generate the perichromic dyes 2b, 3b and 4b, respectively. These dyes were used as probes to investigate the micropolarity of natural cyclodextrins (CyDs) and it was observed that they interact differently with the CyDs according to the molecular structure of the dye and the diameter of the CyD. The solvatochromic bands of the dyes that interacted with the CyDs were bathochromically shifted, suggesting that the probes were transferred to the hydrophobic interior of the CyD in aqueous solution. Dyes 2b and 4b were found to be very selective for α-CyD and γ-CyD, respectively, while β- and γ-CyD changed the color of the solution of compound 3b. These dyes were then successfully used in a simple assay that allows the naked-eye discrimination of natural CyDs in aqueous solution, without the need for expensive techniques.
METHOD FOR PRODUCING A CROSS-COUPLING PRODUCT OF A BENZENOID DIAZONIUM SALT
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Paragraph 0045; 0046; 0047; 0048, (2013/03/26)
The invention relates to a method for producing a cross-coupling product of a benzenoid dizonium salt according to the general formula (I), wherein the groups R1, R2, R3, R4, and R5 represent hydrogen, halogen, an alkyl, alkenyl, aryl, alkoxy, aryloxy, nitro, cyano, hydroxy, acetyl, and/or diazo groups independently of each, and X represents BF4, Cl, F, SO3CH3, CO2CH3, PF6, ClO2CH3, or CIO4, comprising the following steps: (a) providing a benzenoid amide, which with the exception of the diazo function has the same substituents R1, R2, R3, R4, and R5 as the benzenoid diazonium salt of the general formula (I), and hydrolytically cleaving the amide to form an amine or providing a corresponding amine, (b) diazotizing the amine thus obtained or provided with a nitrite, and (c) subsequently reacting the benzenoid diazonium salt with a coupling partner in the presence of a catalyst to form a cross-coupling product, wherein the coupling parter is represented by the general formula (II), R6, R7, and R8 are the same or different and represent hydrogen, carboxyalkyl groups, carboxyaryl groups, alkyl groups, aryl groups, alkoxy groups, aryloxy groups, wherein the groups can each contain Si, N, S, O, and or halogen atoms, or R6 and R7 with the double bound form an aromatic ring, which can be provided with R8 and one to four further substituents, independently of each other, selected from the group comprising a straight-chain or branched (C1-C6) alkyl group, a (C3-C7) cycloalkyl group, a straight-chain or branched (C1-C6) alkenyl group, a straight-chain or branched (C1-C6) alkyoxy group, halogen, the hydroxy group, an amino, di(C1-C6) alkylamino, nitro, acetyl, cyan, benzyl, 4-methoxybenzyl, 4-nitrobenzyl, phenyl, and 4-methoxyphenyl group and represents Y=H, —B(OR)2, —SnR3, —ZnR, —SiR3, or Mg (halogen), and wherein at least the steps (b) and (c) are performed without intermediate isolation of an intermediate product. According to said method, cross-couplings can be performed more simply and with improved yield without the hydroxyl group in aromatic reactants containing hydroxyl groups having to be provided with a protective group.
Bromine-substituted p-nitrostilbene derivatives: Synthesis, crystal structural studies, photoluminescence and the heavy atom effect on the singlet oxygen generation by two-photon absorption
Gao, Fang,Wang, Xinchao,Wang, Suna,Liu, Meng,Liu, Xiaojiao,Ye, Xiaojuan,Li, Hongru
, p. 2720 - 2732 (2013/03/28)
A variety of linear and side-chained p-nitrostilbene derivatives with various numbers of bromine atoms were prepared to survey the crystal structural properties, the photoluminescence, and heavy atom effect on the singlet oxygen generation by two-photo ab
Study of the absorption and emission spectroscopy of "A-B" type photosensitive compounds including two-photon chromophore and benzophenone moiety
Gao, Fang,Hu, Nvdan,Xie, Ting,Cheng, Zhibin,Yang, Long,Liu, Xiaojiao,Li, Zedong,Wang, Xinfu,Li, Hongru,Li, Xueming
experimental part, p. 1006 - 1012 (2009/02/02)
"A-B" type photosensitive compounds including two-photon chromophore and benzophenone moiety have been designed, synthesized and characterized. The UV-vis absorption and fluorescence emission of the compounds have been extensively studied in various solvents. The results show that the absorption of "A-B" type compounds displays obvious double absorption bands, one of which at short-wavelength is related to the benzophenone moiety, the other at long-wavelength is mainly contributed by chromophore. The emission of "A-B" type compounds at 500-700 nm shows an "unexpected" blue-shift comparing with that of the sole chromophore. The photosensitive compounds with amino group display strong emission in apolar solvents and have a low fluorescence quantum yields in polar solvents. In contrast, the compounds without amino group exhibit strong fluorescence emission in polar solvents, and low fluorescence quantum yields in apolar solvents. The fluorescence quantum yields of "A-B" type compounds are higher than those of the sole chromophore. The discoveries suggest that charge redistribution induced by the introduction of benzophenone moiety plays a key role on the absorption and emission spectroscopy.
Synthesis and Characterisation of Liquid Crystalline Polymers for Nonlinear Optical Applications
McCulloch, I. A.,Bailey, R. T.
, p. 157 - 166 (2007/10/02)
A series of side chain liquid crystalline polymers based on a polystyrene backbone has been synthesized and characterized for non-linear optical applications.Keywords: liquid crystal polymers, non-linear, optical, polystyrene
