- A magnetic palladium nickel carbon nanocomposite as a heterogeneous catalyst for the synthesis of distyrylbenzene and biphenyl derivatives
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A magnetic palladium nickel carbon (Fe3O4@Pd@Ni/C) nanocomposite has been synthesized using a simple one-pot procedure via a hydrothermal approach. Ferric nitrate, palladium acetate, and nickel nitrate were dissolved in water together with glucose, and the mixture was heated in an autoclave. The Fe3O4@Pd@Ni/C nanocomposite was characterized via XRD, TEM, FE-SEM, VSM, EDS, and XPS studies. The catalytic abilities of the Fe3O4@Pd@Ni/C nanocomposite were investigated for the synthesis of distyrylbenzene and 9,10-distyrylanthracene derivatives. This method shows obvious advantages, such as the recyclability of the catalyst, simple experimental operation, and the obtaining of good to excellent yields.
- Shafie, Habiballah,Niknam, Khodabakhsh
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supporting information
p. 11697 - 11704
(2021/07/12)
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- Phenylenevinylene oligomers by Mizoroki-Heck cross coupling reaction. Structural and optoelectronic characterization
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In order to study the effect of the molecular structure on the optical properties of totally trans-trans phenylenevinylene oligomers (OPVs), sixteen 1,4-distyrylbenzene derivatives (1a-i and 2a-g) functionalized with different electron-donating (ED) and electron-withdrawing (EW) groups were synthesized by the Mizoroki-Heck cross coupling reaction in moderate to good yields (40–95%). The implemented methodology, with a small modification previously reported by our group, allows obtaining the desired vinyl configuration as well as one novel OPV compound (1h). After structural characterization by several techniques (e.g. FTIR, 1H, 13C and Solid-State NMR), particular emphasis was placed upon the investigation of their optical properties by UV–vis and fluorescence spectroscopies. The results showed that, with only one exception, the ED and EW groups at the ends of OPV systems lead to a bathochromic shift. This effect is intensified with the introduction of methoxy groups on the central ring. Consistent with these, the HOMO-LUMO gaps (ΔE) decreases as the strength of ED and EW substituents increases. The ED and EW substituents also lead to a decrease in the Φf values. This contribution in the area of organic electronics can be used as a reference to better select the most appropriate technological application for each OPV and this can be extrapolated to their respective structurally analogous segmented polymer.
- Estrada, Sandra E.,Ochoa-Puentes, Cristian,Sierra, Cesar A.
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p. 448 - 457
(2016/12/30)
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- Polyaniline-anchored palladium catalyst-mediated Mizoroki-Heck and Suzuki-Miyauraa reactions and one-pot Wittig-Heck and Wittig-Suzuki reactions
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A polyaniline-anchored palladium catalyst was prepared and screened for coupling reactions of aryl halides. The robust and recyclable catalyst was effective in Mizoroki-Heck and Suzuki-Miyaura reactions of aryl bromides and aryl iodides. The catalyst system was further employed for one-pot Wittig-Heck and Wittig-Suzuki combinations to build conjugated compounds in good conversions.
- Patel, Heta A.,Patel, Arun L.,Bedekar, Ashutosh V.
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- One-pot synthesis and study of spectroscopic properties of oligo(phenylenevinylene)s
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Two series of OPVs (oligo(phenylenevinylene)), that is, ((1E,1′E)-(2,5-dimethoxy-1,4-phenylene)bis(ethene-2,1-diyl))dibenzene derivatives and 4-((E)-4-((E)-styryl)styryl)pyridine derivatives with different functional groups of varying electronic properties have been synthesized by one-pot Wittig-Heck methodology. The synthesized derivatives have been studied for their optical properties. Amongst them the ((1E,1′E)-(2,5-dimethoxy-1,4-phenylene)bis(ethene-2,1-diyl))dibenzene derivatives with appropriate changes in the end group showed a significant impact on the UV absorption and emission spectra. Particularly NO2-OPV showed distinct solvatochromism in the wavelength range of 218 nm in different solvents. Whereas 4-((E)-4-((E)-styryl)styryl)pyridine derivatives showed clear acidochromism which can be detected visually as well as spectroscopically.
- Patel, Krupa N.,Bedekar, Ashutosh V.
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p. 6617 - 6621
(2015/11/09)
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- Understanding the unconventional effects of halogenation on the luminescent properties of oligo(phenylene vinylene) molecules
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It is commonly known that halogenation tends to decrease the luminescence quantum yield of an organic dye, owing to the high electronegativity and heavy-atom effect of the halogen atom. However, based on an investigation of the effects of halogenation on the luminescence of the oligo(phenylene vinylene) (OPV) framework, we demonstrate that halogenation can have positive impact on the solid-state fluorescence and electrochemiluminescence (ECL) properties of OPV derivatives. The chlorinated OPV exhibits a very high solid-state fluorescence quantum yield (91 %), whilst the brominated analogue gives the highest ECL emission intensity. Time-dependent density functional theory calculations, natural bond orbital analysis, and natural transition orbital analysis were performed to assist the understanding of the origin of these positive halogenation effects, which provide insight into the rational design of highly luminescent halogenated organic materials for solid-state devices and ECL applications. Copyright
- Sun, Chun-Lin,Li, Jun,Geng, Hong-Wei,Li, Hui,Ai, Yong,Wang, Qiang,Pan, Shan-Lin,Zhang, Hao-Li
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supporting information
p. 3091 - 3100
(2014/01/06)
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- One-pot synthesis of stilbenes by dehydrohalogenation-Heck olefination and multicomponent Wittig-Heck reaction
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A variant of olefination reaction involving in situ generation of styrene by either one-pot dehydrohalogenation-Heck or one-pot multicomponent Wittig-Heck reaction is developed.
- Saiyed, Akeel S.,Bedekar, Ashutosh V.
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experimental part
p. 6227 - 6231
(2011/01/04)
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- Alkoxylated p-phenylenevinylene oligomers: Synthesis and spectroscopic and electrochemical properties
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Twenty-one n-alkoxy substituted phenylenevinylene oligomers were synthesized, varying in size, number and position of the OR groups. IR,MS and solubility data are presented. NMR measurements provided the molecular structure as well as information about conformations and molecular dynamics. UV and of cyclic voltammetric data give correlations of chemical structure (number and position of OR substituents) with separate HOMO and LUMO energies.
- Ndayikengurukiye, Henri,Jacobs, Sven,Tachelet, Wim,Van Der Looy, Johan,Pollaris, Anne,Geise, Herman J.,Claeys, Magda,Kauffmann, Jean M.,Janietz, Silvia
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p. 13811 - 13828
(2007/10/03)
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- Solid state behaviour of vinyl quinones
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2,5-Bisvinyl-1,4-benzoquinones 1 and 2-vinyl-1,4-benzoquinones 2 substituted with aryl or ester end groups have been synthesized. The 2,5-bisstyryl-1,4-benzoquinones 1 (R=phenyl, p-tolyl, o-tolyl) crystallize with a 7 angstrom-stacking axis. But only for the o-tolyl derivative the contacts between the vinyl groups are close enough to allow a four-center type photopolymerization. The ester derivative 1 (R=COOEt) has a layer structure and can be photooligomerized in the crystal. The generated cyclobutane subgroups have twofold symmetry. The vinylquinones 2 (R=aryl) may be dimerized photochemically in the crystal at the vinyl groups to centrosymmetric cyclobutanes. Crystals with 4 angstrom stacking axis are also photoreactive.
- Irngartinger,Lichtenthaeler,Herpich,Stadler
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p. 349 - 360
(2007/10/03)
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- Syntheses and Crystal Structures of 2,5-Bis(2-arylvinyl)-1,4-benzoquinones and their Photochemical Reactivity in the Crystalline State
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The 2,5-bis(2-arylvinyl)-1,4-benzoquinones 1a-1e are formed from hydrolysis of their corresponding ketals 5 which are generated by anodic oxidation of the corresponding 1,4-dimethoxybenzene derivatives 4.The crystal structures of the quinone compounds 1a,
- Irngartinger, Hermann,Lichtenthaeler, Jochen,Fenske, Dieter,Baum, Gerhard
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p. 1411 - 1418
(2007/10/02)
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