- Hexaphenylbenzene based push-pull fluorophores displaying intriguing polarity-dependent fluorescence behavior, AIE(E) characteristics and mega-large Stokes shifts
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In general, most donor-acceptor type fluorophores are known to exhibit solvatochromic behavior and obey the energy gap law simultaneously, showing decreased emission with increasing solvent polarity. In this work, four push-pull hexaphenylbenzene (HPB) derivatives 1–4 have been designed and synthesized by introducing methoxy and dicyanovinyl groups at the tip of aromatic blades, which behave exceptionally polarity-dependent emission properties. In the low to medium solvent polarity region, the four dipole fluorophores display gradually enhanced fluorescence, whereas a reverse trend is observed with the further increase of solvent polarity. Meanwhile, 1–4 are found to exhibit the strongest emission at the same wavelength remarkably, which appears to be somewhat relevant to the intrinsic characteristics of dicyanovinyl-phenyl acceptor. A mechanistic scheme containing a conical intersection (CI) has been proposed to explain the up-down emission of 1–4 with increasing solvent polarity. Large Stokes shifts (up to 254 nm) and AIE(E) characteristics have also been achieved in these four HPB fluorophores. Besides, fluorophores 1–4 exhibit obvious freezing-solution induced chromism (FSIC), demonstrating an enhancement of the local matrix polarity upon freezing solutions.
- Cao, Xiaohui,Li, Si,Li, Yan,Xu, Bo,Yang, Qiusheng,Yin, Guohui,Zhang, Yuecheng,Zhao, Jiquan
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- Investigating the change in the photophysical properties of a trio of tetraphenylcyclopentadienone derivatives with varied groups on the aromatic rings in the 3- and 4-positions
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Organic compounds with electronic properties, such as a small band gap, are useful in areas ranging from organic field effect transistors to solar cells. Such organic compounds can possess conjugation and/or aromatic systems, with one example being tetrap
- Orozco, Arnoldo J.,Joachim, Kole,Ruiz, Henry D.,Fronczek, Frank R.,Isovitsch, Ralph
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p. 247 - 255
(2020/09/16)
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- Application of silica-supported Shvo's catalysts for transfer hydrogenation of levulinic acid with formic acid
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Two triethoxysilylpropoxy-functionalized Shvo's catalyst precursors were synthesized and characterized by IR, NMR and HRMS. Both covalent anchoring and sol-gel methods were used for their immobilization. The homogeneous and immobilized catalysts were used for the transfer hydrogenation of levulinic acid with formic acid to form hydroxyvaleric acid, which was readily dehydrated to yield gamma-valerolactone. The immobilized catalysts prepared by the sol-gel method showed higher activity than the covalently grafted catalysts. Hot filtration tests showed no leaching of the immobilized Shvo's catalysts, opening the door to facile catalyst recycling.
- He, Dongmei,Horváth, István T.
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p. 263 - 269
(2017/09/12)
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- Polysiloxanes-based stationary phases containing methoxy-substituted tetraphenyl-phenyl groups for gas chromotographic separations
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3,4-Di(4-methoxy phenyl)-2,5-diphenyl phenyl grafted polysiloxane (MTP) and 3,4-di(3,4,5-trimethoxy phenyl)-2,5-diphenyl phenyl grafted polysiloxane (TMP) were synthesized and statically coated on fused silica capillary columns. The MTP and TMP columns have efficiencies of almost 3400 (k = 3.74, 0.25 mm i.d.) and 3600 (k = 3.96, 0.25 mm i.d.) plates per m, respectively, which are determined by naphthalene at 120 °C. Both columns exhibited moderate polarity based on the McReynolds constants. The separation of the polyethylene pyrolysis products shows that the maximum operating temperature of the two columns can reach up to 360 °C and 370 °C, respectively. In addition, the solvation parameter indicated that the dipole-induced dipole, H-bond alkaline, and dispersive interactions were the main interactions between the solutes and the stationary phases. The separation performance of the new columns was evaluated by gas chromatography separation of the Grob test mixtures. Several mixtures with π-conjugated structure were also well separated on the new columns. This work demonstrated the promising future of the new type of stationary phases in GC analysis.
- He, Xinxin,Han, Xue,Wang, Huan,Wang, Bing,Wu, Bo
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p. 76514 - 76523
(2016/08/30)
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- Microwave-assisted synthesis of functionalized Shvo-type complexes
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A simple and expeditious microwave-assisted procedure for the synthesis of a variety of Shvo-type ruthenium complexes has been developed by reacting Ru3(CO)12 with variously functionalized tetraarylcyclopentadienones under microwave irradiation in MeOH. Ligand precursors have also been prepared under microwave heating by a bis-aldol condensation of 1,3-diphenylacetone with variously functionalized aromatic diketones. All the reactions were very fast and clean, leading to good yields and purities.
- Cesari, Cristiana,Sambri, Letizia,Zacchini, Stefano,Zanotti, Valerio,Mazzoni, Rita
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p. 2814 - 2819
(2014/06/24)
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- Racemisation of 1-arylethylamines with Shvo-type organoruthenium catalysts
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Variation of the electronic nature of the tetraphenylcyclopentadienone ligand in organoruthenium complexes influences their utility for racemisation of model chiral amines. Our study highlights the need to balance reactivity and selectivity in the design of racemisation catalysts. Electron-poor Shvo-type catalysts are, at first sight, more effective for racemisation, but yield more by-product; electron-rich complexes are less proficient at racemisation, but lead to less by-product.
- Apps, James F. S.,Livingston, Andrew G.,Parrett, Mark R.,Pounder, Ryan J.,Taylor, Paul C.,Turner, Andrew R.
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p. 1391 - 1394
(2014/06/23)
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- Efficient synthesis of substituted polyarylphthalimides via cycloaddition of cyclopentadienones with 2-bromomaleimide
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Functionalized tetraarylphthalimides or diarylphthalimides fused with an acenaphthene moiety have been prepared in one step from 2-bromomaleimide and tetraarylcyclopentadienones (tetracyclones) or 7,9-diaryl-8H- cyclopentacenaphthylene-8-ones (acecyclones
- Vanel, Rémi,Berthiol, Florian,Bessières, Bernard,Einhorn, Cathy,Einhorn, Jacques
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supporting information; experimental part
p. 1293 - 1295
(2011/07/07)
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- Synthesis of some cyclopentenones and crystal structure of 4-hydroxy-3,4-bis(4-methoxyphenyl)-5,5-dimethyl-2-cyclopenten-1-one
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Sodium-hydroxide-catalyzed condensation of di-p-methyl- and di-p-methoxybenzil with acetone derivatives was investigated in methanol. Di- and trisubstituted products were obtained as cyclopentenones, while tetraaryl-substituted systems were isolated as cy
- Marjani, Katayoun,Mousavi, Mohsen,Arazi, Omid,Ashouri, Akram,Bourghani, Samira,Rajabi, Mohammad
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experimental part
p. 1331 - 1336
(2010/06/14)
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- Cycloaddition of benzo[b]thiophene-S,S-dioxide - A route to substituted dibenzothiophenes and dibenzothiophene S,S-dioxides
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Benzo[b]thiophene S,S-dioxide can be transformed by cycloaddition with tetraarylthiophene S-oxides to tetraaryldibenzothiophene S,S-dioxides. An analogous cycloaddition of benzo[b]thiophene S,S-dioxide, albeit at higher temperatures, leads directly to tet
- Iniesta, Jesus,Matsumoto, Taisuke,Thiemann, Thies
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experimental part
p. 109 - 114
(2009/08/07)
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- Hexaphenylphenylene dendronised pyrenylamines for efficient organic light-emitting diodes
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A series of blue-emitting triarylamines containing pyrene and hexaphenylbenzene dendrons were successfully synthesized by employing the Diels-Alder and palladium catalyzed C-N coupling reactions. They display high glass transition temperatures (>140°C) in
- Thomas, K.R. Justin,Velusamy,Lin, Jiann T.,Chuen,Tao, Yu-Tai
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p. 4453 - 4459
(2007/10/03)
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- Energy harvesting star-shaped molecules for electroluminescence applications
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Novel energy harvesting molecules featuring hexaarylbenzene based triarylamine donors and a dithienyl benzothiadiazole acceptor, and that emit red light in electroluminescent devices, have been prepared for the first time.
- Justin Thomas,Velusamy, Marappan,Lin, Jiann T.,Sun, Shih-Sheng,Tao, Yu-Tai,Chuen, Chang-Hao
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p. 2328 - 2329
(2007/10/03)
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