50 results on '"Hexaphenylbenzene"'
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2. Tetraphenylethylene-functionalized hexaphenylbenzene with unique conformation-driven selectivity for gas chromatographic separations
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Yinhui Yang, Meiling Qi, and Jinliang Wang
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chemistry.chemical_classification ,Chromatography ,General Chemistry ,Tetraphenylethylene ,Catalysis ,chemistry.chemical_compound ,chemistry ,Capillary column ,Impurity ,Stationary phase ,Materials Chemistry ,Selectivity ,Aromatic hydrocarbon ,Hexaphenylbenzene - Abstract
Here we report a novel hexaphenylbenzene (HPB)-based material functionalized with six tetraphenylethylene units (BPT) with unique conformation-driven selectivity for gas chromatographic (GC) separations. It is composed of a neat aromatic hydrocarbon with a rigid propeller-like conformation. As a result, the BPT capillary column exhibited high column efficiency of 5340 plates per m and high-resolution capability for aromatic to aliphatic isomers with excellent intra-day and inter-day repeatability and between-column reproducibility. The results demonstrate the unique conformation-driven selectivity of the HPB-based stationary phase, which is rarely reported for chromatography. Moreover, its application in the determination of isomer impurities in commercial products proved its good potential for practical GC analysis. This work presents a new perspective for developing selective stationary phases by engineering their structures. more...
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- 2020
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Catalog
3. Simultaneous realization of high-efficiency, low-drive voltage, and long lifetime TADF OLEDs by multifunctional hole-transporters
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Yoshihito Sukegawa, Takahiro Kamata, Junji Kido, Hisahiro Sasabe, Takayuki Chiba, Nozomi Ito, Ayato Arai, and Daisuke Yokoyama
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chemistry.chemical_compound ,Materials science ,chemistry ,business.industry ,Materials Chemistry ,OLED ,Optoelectronics ,Quantum efficiency ,General Chemistry ,business ,Hexaphenylbenzene ,Realization (systems) ,Voltage - Abstract
Although organic light emitting devices (OLEDs) based on thermally activated delayed fluorescence (TADF) have already achieved impressively high external quantum efficiency (ηext) of over 35%, their operation lifetime still needs to be improved for practical applications. In this study, we developed a molecular design for fabricating high triplet energy (ET = 2.7 eV) multifunctional hole-transport layers (HTLs) based on a hexaphenylbenzene skeleton to realize record-breaking efficient and stable TADF OLEDs. By using a dibenzofuran-end-capped HTL named 4DBFHPB, we could successfully develop a highly efficient, low-drive voltage, and stable green TADF OLED exhibiting an ηext of 19.2% and operation lifetime (LT50) of ∼24 000 h at an initial luminance of 1000 cd m−2. The drive voltage at 1000 cd m−2 was recorded to be 4.07 V. We also developed a sky-blue TADF OLED exhibiting an ηext of 21.5% and LT50 of ∼1700 h at an initial luminance of 500 cd m−2. The developed designs demonstrate record-breaking performances among the existing TADF OLEDs. more...
- Published
- 2020
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4. One-pot synthesis of conjugated microporous polymers based on extended molecular graphenes for hydrogen storage
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Qin Minglin, Wusong Jin, Yue Zhang, Dengqing Zhang, Xuebo Zhao, Xianying Li, and Wang Zeng
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Polymers and Plastics ,Chemistry ,Organic Chemistry ,One-pot synthesis ,02 engineering and technology ,Microporous material ,010402 general chemistry ,021001 nanoscience & nanotechnology ,01 natural sciences ,0104 chemical sciences ,Conjugated microporous polymer ,Hydrogen storage ,chemistry.chemical_compound ,Adsorption ,Chemical engineering ,Polymerization ,Materials Chemistry ,Molecule ,0210 nano-technology ,Hexaphenylbenzene - Abstract
Incorporation of highly extended π-conjugated molecules into conjugated microporous polymers (CMPs) is one of the important aspects in material science. Herein we synthesize conjugated microporous polymers (CMP-Gs) with covalently linked molecular graphenes by an efficient tandem oxidative reaction in one-pot, which comprising Scholl-type cyclodehydrogenation and oxidative polymerization. Oxidation of m- or p-thienyl decorated hexaphenylbenzene derivatives with excess of FeCl3 allowing in situ generation of size-controlled graphitic segments form CMP-G1 and CMP-G2 in high yields, respectively. CMP-Gs possess large surface areas and micropore size from 0.5 to 1.5 nm. Gravimetric hydrogen adsorption isotherms show that the adsorption capacity for hydrogen is up to 2.69 wt% for CMP-G1 and 2.14 wt% for CMP-G2 at 20 bar and 77 K, respectively. more...
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- 2019
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5. Optically active triptycenes containing hexa-peri-hexabenzocoronene units
- Author
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Tomoyuki Ikai, Ken-ichi Shinohara, and Yuya Wada
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Materials science ,010405 organic chemistry ,Metals and Alloys ,General Chemistry ,010402 general chemistry ,01 natural sciences ,Catalysis ,0104 chemical sciences ,Surfaces, Coatings and Films ,Electronic, Optical and Magnetic Materials ,law.invention ,Crystallography ,chemistry.chemical_compound ,Hexabenzocoronene ,chemistry ,law ,Triptycene ,Materials Chemistry ,Ceramics and Composites ,Molecule ,Crystallization ,Luminescence ,Hexaphenylbenzene ,Circular polarization ,Derivative (chemistry) - Abstract
A pair of novel optically active triptycene-based molecules ((R,R)-1 and (S,S)-1) containing two hexabenzocoronene moieties were synthesized and their optical and chiroptical properties were investigated. Optically active 1 emitted preferred-handed circularly polarized light upon UV irradiation, with the luminescence dissymmetry factors found to be approximately 1.0 × 10-3. Based on a comparative study using the analogous triptycene derivative with two hexaphenylbenzene units (2), which was the key precursor of 1, the ladder-type rigid structure with an asymmetrically bent geometry was important for optically active 1 to exhibit circularly polarized luminescence (CPL). We also showed that rac-1 undergoes conglomerate crystallization, which allowed CPL to be produced by a random selection of crystals prepared from rac-1. more...
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- 2019
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6. A propeller-shaped perylene diimide hexamer as a nonfullerene acceptor for organic solar cells
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Zhishan Bo, Cuihong Li, Juncheng Liu, Miao Li, Xinjun Xu, Xuebo Chen, Sufei Xie, Liangliang Wu, and Shiyu Feng
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Materials science ,Organic solar cell ,02 engineering and technology ,General Chemistry ,Random hexamer ,010402 general chemistry ,021001 nanoscience & nanotechnology ,Photochemistry ,01 natural sciences ,Acceptor ,0104 chemical sciences ,Active layer ,chemistry.chemical_compound ,chemistry ,Diimide ,Materials Chemistry ,Molecule ,0210 nano-technology ,Hexaphenylbenzene ,Perylene - Abstract
A novel propeller-shaped molecule (HPB-PDI6) with a hexaphenylbenzene (HPB) core and six peripheral PDI units was synthesized via Co2(CO)8-catalyzed cyclotrimerization and used as an acceptor for organic solar cells (OSCs). The intriguing geometry of the HPB core and the spatial repulsion of the PDI rings created a twisted three-dimensional propeller-shaped conformation for HPB-PDI6. The propeller-shaped conformation could prevent the acceptor molecules from forming large aggregates in the active layer. As expected, the PTB7-Th:HPB-PDI6 blend films show a favorable morphology as well as high and balanced charge carrier mobility. Devices based on PTB7-Th:HPB-PDI6 achieved a PCE of 6.63% with a Voc of 0.92 V, a Jsc of 15.11 mA cm−2, and an FF of 48.0%. Our results have demonstrated that the easily prepared propeller-shaped HPB-PDI6 could be a promising acceptor for high efficiency organic solar cells. more...
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- 2018
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7. Hexaphenylbenzene appended AIEE active FRET based fluorescent probe for selective imaging of Hg2+ ions in MCF-7 cell lines
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Shahi Imam Reja, Pardeep Kaur, Manoj Kumar, Vandana Bhalla, Saroj Arora, Gurpreet Singh, and Davinder Kaur
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010405 organic chemistry ,Metal ions in aqueous solution ,Metals and Alloys ,Analytical chemistry ,chemistry.chemical_element ,010402 general chemistry ,Condensed Matter Physics ,Photochemistry ,01 natural sciences ,Fluorescence ,0104 chemical sciences ,Surfaces, Coatings and Films ,Electronic, Optical and Magnetic Materials ,Ion ,Mercury (element) ,chemistry.chemical_compound ,Förster resonance energy transfer ,chemistry ,MCF-7 ,Cell culture ,Materials Chemistry ,Electrical and Electronic Engineering ,Instrumentation ,Hexaphenylbenzene - Abstract
Hexaphenylbenzene (HPB) appended rhodamine derivative 4 has been synthesized which exhibits aggregation-induced emission enhancement (AIEE) characteristics and forms fluorescent aggregates in mixed aqueous media. These aggregates show remarkable fluorescence resonance energy transfer (FRET) in the presence of Hg 2+ ions among various metal ions tested. Further these aggregates were also utilized for the ratiometric imaging of Hg 2+ ions in MCF-7 cell lines. more...
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- 2017
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8. Hexaphenylbenzene-based fluorescent aggregates for detection of zinc and pyrophosphate ions in aqueous media: tunable self-assembly behaviour and construction of a logic device
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Manoj Kumar, Vandana Bhalla, and Subhamay Pramanik
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In situ ,010405 organic chemistry ,Inorganic chemistry ,chemistry.chemical_element ,General Chemistry ,Zinc ,010402 general chemistry ,Photochemistry ,01 natural sciences ,Pyrophosphate ,Fluorescence ,Catalysis ,0104 chemical sciences ,Ion ,chemistry.chemical_compound ,chemistry ,Materials Chemistry ,Self-assembly ,Hexaphenylbenzene ,Derivative (chemistry) - Abstract
Hexaphenylbenzene based derivative 7 has been synthesized which formed spherical aggregates in mixed aqueous media. These aggregates exhibited an “on–on” response towards Zn2+ ions in aqueous media. Further, this sensing event was accompanied by the modulation of the self-assembly of aggregates from spherical structures to microrods in aqueous media. This in situ prepared 7-Zn2+ ensemble was utilized as a “not quenched” probe for the selective and sensitive detection of PPi ions in aqueous media. In addition, based upon the fluorescent signals of derivative 7 as outputs (λem = 450 and 370 nm) in the presence of chemical inputs (Zn2+ and PPi), we developed a combinatorial logic circuit with INHIBIT and AND gates. more...
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- 2017
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9. New comb-shaped ionomers based on hydrophobic poly(aryl ether ketone) backbone bearing hydrophilic high concentration sulfonated micro-cluster
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Liming Lin, Sinan Feng, Zhenhua Jiang, Zheng Chen, Zhenpeng Zhang, Bei Liu, Haibo Zhang, and Jinhui Pang
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chemistry.chemical_classification ,Condensation polymer ,Materials science ,Ketone ,Polymers and Plastics ,Aryl ,Organic Chemistry ,Ether ,02 engineering and technology ,010402 general chemistry ,021001 nanoscience & nanotechnology ,01 natural sciences ,0104 chemical sciences ,chemistry.chemical_compound ,Membrane ,Monomer ,chemistry ,Nafion ,Polymer chemistry ,Materials Chemistry ,0210 nano-technology ,Hexaphenylbenzene - Abstract
A new difluoride monomer containing an aliphatic bridge between 2,6-difluoropheyl and hexaphenylbenzene is designed and synthesized. Then, a series of novel hexa-sulfonated poly(aryl ether ketone)s (HS-PAEK-x) containing an aliphatic spacer between hydrophobic poly(aryl ether ketone)s main chain and hydrophilic sulfonated hexaphenylbenzene are prepared from the new difluoride monomer with 4,4′-(hexafluoroisopropylidene) diphenol and 4,4′-difluorobenzophenone by nucleophilic polycondensation, and subsequent postsulfonation using chlorosulfonic acid. All the polymers give tough, flexible, and transparent membranes by solvent casting. The membranes with comparatively low ion exchange capacity (IEC) values ranging from 0.87 to 1.42 meq g−1, achieve good mechanical properties, suitable proton conductivity (111 mS cm−1) compared with Nafion 117 at 80 °C, and excellent dimensional stability (the highest swelling ratio of length is 9.2% at 80 °C). Furthermore, compared with the previous reported polymers with similar main chain, such as the polymer with pendant sulfoalkyl groups and hollow aromatic hexa-sulfonated polymer, the HS-PAEK-x exhibit higher proton conductivities at similar IEC level, which attributes to the specific molecular structure and improving morphology. Overall, all of the above-mentioned results indicate that the HS-PAEK-x membranes are good candidate materials for proton exchange membranes (PEMs). more...
- Published
- 2016
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10. Strong Physical Hydrogels from Fibrillar Supramolecular Assemblies of Poly(ethylene glycol) Functionalized Hexaphenylbenzenes
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George Fytas, Dimitris Vlassopoulos, Katrin Wunderlich, Markus Klapper, Klaus Müllen, and John Marakis
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Polymers and Plastics ,Organic Chemistry ,technology, industry, and agriculture ,Supramolecular chemistry ,macromolecular substances ,02 engineering and technology ,010402 general chemistry ,021001 nanoscience & nanotechnology ,01 natural sciences ,Micelle ,0104 chemical sciences ,Inorganic Chemistry ,Hydrophobic effect ,chemistry.chemical_compound ,chemistry ,Amphiphile ,Self-healing hydrogels ,Polymer chemistry ,Materials Chemistry ,0210 nano-technology ,Ethylene glycol ,Hexaphenylbenzene ,Macromolecule - Abstract
Gel formation without chemical cross-links requires strong physical bonds, as observed in diverse molecular and macromolecular systems or supramolecular assemblies above a critical concentration. Here, we present a new molecular amphiphile of propeller-like hexaphenylbenzene derivative bearing two short poly(ethylene glycol) (PEG) chains which forms reversible physical gels comprising long (∼2.2 μm) bundles of hydrogel fibrils in coexistence with spherical micelles. Combination of topological (entanglement-like) interactions between the fibers and specific hydrophobic interactions due to the helicity of the PEG chains is proposed to account for the hydrogelation in the semidilute regime. The present supramolecular hydrogels, which are based on small molecules, exhibit extraordinary properties with an exceptionally strong dependence of the shear modulus on concentration, akin to the behavior of ultrahigh molecular weight cellulose-based fibers. more...
- Published
- 2016
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11. Sharp difference in the change in molar volumes and enthalpy of dissolution of 2D and 3D molecules in solvents illustrated by the Diels-Alder reaction
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Vladimir D. Kiselev, Dmitry A. Kornilov, and Anastasia O. Kolesnikova
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Enthalpy ,02 engineering and technology ,010402 general chemistry ,021001 nanoscience & nanotechnology ,Condensed Matter Physics ,01 natural sciences ,Atomic and Molecular Physics, and Optics ,0104 chemical sciences ,Electronic, Optical and Magnetic Materials ,Adduct ,Enthalpy change of solution ,Solvent ,chemistry.chemical_compound ,Molar volume ,chemistry ,Phase (matter) ,Materials Chemistry ,Physical chemistry ,Physical and Theoretical Chemistry ,0210 nano-technology ,Dissolution ,Hexaphenylbenzene ,Spectroscopy - Abstract
A sharp difference in the change in the molar volume during the transition from the solid phase to the solution for a number of 2D molecules of reagents compared with 3D molecules of the Diels-Alder reaction adducts was observed. The dissolution of 2D crystal molecules is accompanied by a significant increase in volume (10–15%) with a dissolution enthalpy close in magnitude to the fusion enthalpy. A similar transition for 3D crystal molecules is often accompanied by an unexpected decrease in volume and even negative enthalpy of dissolution in inert solvents. The similar change in these parameters is also considered for a number of 3D molecules: 1,3,5-triphenylbenzene, hexaphenylbenzene, 9,10-diphenylanthracene, congressane, and C-60 fullerene. This can be explained by the fact that the surface of large 3D molecules in a solution can be much more thoroughly surrounded by solvent molecules than in its own environment. These results indicate that the values of activation and reaction volumes and their ratio (ΔV≠S/ΔVr-n, S) may be weakly related to the mechanism of non-polar cycloaddition reactions. more...
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- 2020
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12. Carbon-rich 'Click' 1,2,3-triazoles: hexaphenylbenzene and hexa-peri-hexabenzocoronene-based ligands for Suzuki–Miyaura catalysts
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James D. Crowley, Nigel T. Lucas, and James R. Wright
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chemistry.chemical_classification ,010405 organic chemistry ,Chemistry ,Metals and Alloys ,Hexa-peri-hexabenzocoronene ,chemistry.chemical_element ,General Chemistry ,010402 general chemistry ,01 natural sciences ,Copper ,Catalysis ,Cycloaddition ,0104 chemical sciences ,Surfaces, Coatings and Films ,Electronic, Optical and Magnetic Materials ,Coordination complex ,chemistry.chemical_compound ,Materials Chemistry ,Ceramics and Composites ,Organic chemistry ,Hexaphenylbenzene ,Carbon ,Palladium - Abstract
Hexaphenylbenzene (HPB) and hexa-peri-hexabenzocoronene-(HBC) functionalised 1,2,3-triazoles have been synthesised using an optimised copper(i)-catalysed azide-alkyne cycloaddition (CuAAC) reaction. The coordination chemistry of these ligands was explored through the synthesis of the respective palladium(ii) complexes and their activity as catalysts in the Suzuki-Miyaura reaction assessed. more...
- Published
- 2016
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13. Synthesis and properties of organic microporous polymers from the monomer of hexaphenylbenzene based triptycene
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Peng-Cheng Zhu, Liu-Ning Luo, Chun Zhang, San-Yuan Ding, Jun-Min Liu, Ying Liu, Bien Tan, Huibi Xu, Liangxiao Tan, and Xiangliang Yang
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chemistry.chemical_classification ,Materials science ,Polymers and Plastics ,Organic Chemistry ,Sorption ,02 engineering and technology ,Microporous material ,Polymer ,Carbon-13 NMR ,010402 general chemistry ,021001 nanoscience & nanotechnology ,01 natural sciences ,0104 chemical sciences ,chemistry.chemical_compound ,Monomer ,chemistry ,Triptycene ,Polymer chemistry ,Materials Chemistry ,Absorption (chemistry) ,0210 nano-technology ,Hexaphenylbenzene - Abstract
An expanded triptycene (hexaphenylbenzene based triptycene) monomer was synthesized from triiodotriptycene. Using this monomer, two kinds of organic microporous polymers HTPs (HTP-A and HTP-B) were prepared by Friedel–Crafts and Scholl reactions. Their structure and properties were characterized by FT-IR, solid 13C NMR, powder XRD, SEM, TEM and gas absorption. Nitrogen sorption analysis displayed that the BET surface areas are 569 and 914 m2 g−1 for HTP-A and HTP-B, respectively. For HTP-B, they can reversibly absorb 1.09 wt % H2 (1.0 bar and 77 K) and 10.3 wt% CO2 (1.0 bar and 273 K), respectively. more...
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- 2016
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14. Development of a supramolecular ensemble of an AIEE active hexaphenylbenzene derivative and Ag@Cu2O core–shell NPs: an efficient photocatalytic system for C–H activation
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Radhika Chopra, Manoj Kumar, and Vandana Bhalla
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Benzimidazole ,010405 organic chemistry ,Metals and Alloys ,Supramolecular chemistry ,Nanoparticle ,Nanotechnology ,General Chemistry ,010402 general chemistry ,Photochemistry ,01 natural sciences ,Catalysis ,0104 chemical sciences ,Surfaces, Coatings and Films ,Electronic, Optical and Magnetic Materials ,Core shell ,chemistry.chemical_compound ,chemistry ,Materials Chemistry ,Ceramics and Composites ,Photocatalysis ,Imidazole ,Hexaphenylbenzene - Abstract
A supramolecular ensemble having Ag@Cu2O core-shell nanoparticles stabilized by aggregates of a hexaphenylbenzene derivative has been developed which exhibits excellent photocatalytic efficiency in reactions involving preparation of imidazole and benzimidazole derivatives via C-H activation. more...
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- 2016
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15. A hexaphenylbenzene based AIEE active two photon probe for the detection of hydrogen sulfide with tunable self-assembly in aqueous media and application in live cell imaging
- Author
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Subhamay Pramanik, Vandana Bhalla, Manoj Kumar, Hwan Myung Kim, Hyo Won Lee, and Hardev Singh
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Supramolecular chemistry ,Nanotechnology ,Photochemistry ,Catalysis ,chemistry.chemical_compound ,Two-photon excitation microscopy ,Live cell imaging ,Microscopy ,Benzene Derivatives ,Materials Chemistry ,Humans ,Hydrogen Sulfide ,Hexaphenylbenzene ,Fluorescent Dyes ,Photons ,Chemistry ,Metals and Alloys ,Water ,General Chemistry ,equipment and supplies ,Fluorescence ,Surfaces, Coatings and Films ,Electronic, Optical and Magnetic Materials ,Microscopy, Fluorescence, Multiphoton ,Ceramics and Composites ,Self-assembly ,Derivative (chemistry) ,HeLa Cells - Abstract
Supramolecular aggregates of hexaphenylbenzene derivative 2 exhibit aggregation induced emission enhancement and modulation of self-assembled architecture from spherical to flower-like assembly in the presence of H2S. Furthermore, probe 2 displays higher photostability, low toxicity and bright green fluorescence in two-photon microscopy (TPM) imaging for the detection of H2S in live HeLa cells. more...
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- 2015
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16. Synthesis and properties of polyimides having a hexaphenylbenzene unit
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Atsushi Morikawa and Syuta Nabeshima
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chemistry.chemical_classification ,Materials science ,Polymers and Plastics ,Organic Chemistry ,Polymer ,Dynamic mechanical analysis ,Thermogravimetry ,chemistry.chemical_compound ,Differential scanning calorimetry ,chemistry ,Polymerization ,Polymer chemistry ,Materials Chemistry ,Imide ,Glass transition ,Hexaphenylbenzene - Abstract
Aromatic polyimides (PIs) with a hexaphenylbenzene unit were synthesized from 1,4-bis[4-(4-aminophenoxy)phenyl]-2,3,5,6-tetraphenylbenzene (1) and various tetracarboxylic dianhydrides by a conventional two-step procedure that included ring-opening polymerization in N-methyl-2-pyrrolidone and subsequent thermal cyclic dehydration. The PIs were characterized by X-ray diffraction, differential scanning calorimetry, thermogravimetry, and dynamic mechanical analysis. The PIs had glass transition temperatures in the range of 289–352°C, and all the polymers were amorphous. The structure–property relationships of these PIs were examined and compared with those of the previously prepared analogous PIs from 4,4′-bis(4-aminophenoxy)biphenyl (2) and 4,4′-bis(4-amino-2-phenylphenoxy)biphenyl (3). Water absorption and dielectric constants of the PIs were also compared and discussed on the basis of imide content per repeating unit. more...
- Published
- 2014
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17. Substituent Effects on the Gas Sorption and Selectivity Properties of Hexaphenylbenzene and Hexabenzocoronene Based Porous Polymers
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Sumudu N. Wijenayake, Atef Kokash, Mohammad Jahangiri, Zachary Tran, Christina M. Thompson, Ronald A. Smaldone, Obada Alfarawati, and Gregory T. McCandless
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chemistry.chemical_classification ,Polymers and Plastics ,Organic Chemistry ,Substituent ,Sonogashira coupling ,Sorption ,Polymer ,Inorganic Chemistry ,chemistry.chemical_compound ,Hexabenzocoronene ,Monomer ,chemistry ,Chemical engineering ,Materials Chemistry ,Organic chemistry ,Selectivity ,Hexaphenylbenzene - Abstract
Herein we report a series of porous organic polymers (POPs) synthesized through a Sonogashira cross-coupling reaction containing hexaphenylbenzene (HEX) and hexabenzocoronene (HBC) with varying peripheral substitution. We observed vastly different gas sorption properties depending on substituent size and the extent of conjugation in the monomer core structure with BET surface areas ranging from 320 m2/g for HBC-POP-4 to 1140 m2/g for HEX-POP-3. In order to more clearly understand the effects of functional group substitution on the properties of these materials, we have characterized these POPs using N2, CO2, and H2 sorption measurements, powder X-ray diffraction, FT-IR spectroscopy, TGA, and EDX. more...
- Published
- 2014
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18. Gas Permeability of Hexaphenylbenzene Based Polymers of Intrinsic Microporosity
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Gabriele Clarizia, Johannes C. Jansen, Mariolino Carta, Neil B. McKeown, and Paola Bernardo
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chemistry.chemical_classification ,Materials science ,Polymers and Plastics ,Diffusion ,Organic Chemistry ,hexaphenylbenzene ,Sorption ,Polymer ,Inorganic Chemistry ,Solvent ,chemistry.chemical_compound ,chemistry ,Chemical engineering ,Permeability (electromagnetism) ,Polymer of Intrinsic Microporosity ,Materials Chemistry ,Organic chemistry ,Gaseous diffusion ,Solubility ,gas separation ,membrane ,Hexaphenylbenzene - Abstract
The synthesis and characterization of a series of novel hexaphenylbenzene (HPB) based polymers of intrinsic microporosity (PIM-HPBs) containing methyl, bromine, and nitrile substituents are reported. The successful formation of thin films from these polymers allowed the evaluation of the influence of the substituents on intrinsic microporosity and gas permeability. Analysis by the time-lag method also yielded information about gas diffusion coefficients and, indirectly, the gas solubility. The gas permeability varies as a function of the polarity of the substituents and shows a significant increase after treatment of the samples with methanol, especially for films cast from THF as the solvent. This enhancement, which is mostly due to an increase in the diffusion coefficient, is only partially lost upon aging of the membranes for 5 months. Measurements at different feed pressures confirm the typical dual mode sorption behavior, with increasing diffusivity and decreasing permeability and solubility as a function of the feed pressure. more...
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- 2014
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19. Highly Efficient and Reversible Iodine Capture in Hexaphenylbenzene-Based Conjugated Microporous Polymers
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Zihao Ren, Charl F. J. Faul, Jens Weber, Benjamin M. Mills, and Yaozu Liao
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Polymers and Plastics ,conjugated microporous polymers ,02 engineering and technology ,010402 general chemistry ,7. Clean energy ,01 natural sciences ,Conjugated microporous polymer ,Inorganic Chemistry ,chemistry.chemical_compound ,reversibility ,recyclability ,Oxidation state ,Diamine ,Materials Chemistry ,Organic chemistry ,Porosity ,Benzene ,Hexaphenylbenzene ,Aryl ,Organic Chemistry ,021001 nanoscience & nanotechnology ,0104 chemical sciences ,chemistry ,Chemical engineering ,Amine gas treating ,0210 nano-technology ,iodine capture - Abstract
The effective and safe capture and storage of radioactive iodine (129I or 131I) is of significant importance during nuclear waste storage and nuclear energy generation. Here we present detailed evidence of highly efficient and reversible iodine capture in hexaphenylbenzene-based conjugated microporous polymers (HCMPs), synthesized via Buchwald–Hartwig (BH) cross-coupling of a hexakis(4-bromophenyl)benzene (HBB) core and aryl diamine linkers. The HCMPs present moderate surface areas up to 430 m2 g−1, with narrow pore size distribution and uniform ultra-micropore sizes of less than 1 nm. Porous properties are controlled by the strut lengths and rigidities of linkers, whilst porosity and uptake properties can be tuned by changing the oxidation state of the HCMPs. The presence of a high number of amine functional groups combined with microporosity provides the HCMPs with extremely high iodine affinity with uptake capacities up to 316 wt%, which is, to the best of our knowledge, the highest reported to date. Two ways to release the adsorbed iodine were explored: either slow release into ethanol or quick release upon heating (with a high degree of control). Spectral studies indicate that the combination of microporosity, amine functionality and abundant π-electrons ensured well-defined host−guest interactions and controlled uptake of iodine. In addition, the HCMPs could be recycled whilst maintaining 90% iodine uptake capacity (up to 295%). We envisage wider application of these materials in the facile uptake and removal of unwanted oxidants from the environment. more...
- Published
- 2016
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20. Porous Organic Polymers Based on Propeller-Like Hexaphenylbenzene Building Units
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Jin-Xiang Wang, Min Luo, Chao-Guo Yan, Ding Zhou, Bao-Hang Han, Tao Wang, Ying Han, Chang-Shan Zhang, and Qi Chen
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chemistry.chemical_classification ,Materials science ,Polymers and Plastics ,Hydrogen ,Organic Chemistry ,chemistry.chemical_element ,Polymer ,Inorganic Chemistry ,chemistry.chemical_compound ,Adsorption ,chemistry ,Physisorption ,Chemical engineering ,Polymerization ,Specific surface area ,Polymer chemistry ,Materials Chemistry ,Gravimetric analysis ,Hexaphenylbenzene - Abstract
Hexaphenylbenzene-based porous organic polymers are prepared smoothly through palladium-catalyzed C–C coupling polymerization. According to the obtained nitrogen physisorption isotherms, the Brunauer–Emmett–Teller specific surface area for these polymers varies between 742 and 1148 m2 g–1. Gravimetric hydrogen adsorption isotherms show that the adsorption capacity for hydrogen is up to 1.5 wt % at 1.13 bar and 77 K. Thanks to the propeller-like structure, unique electronic feature, and efficient preparation, hexaphenylbenzene can be taken as a promising building block for designing porous polymers with special properties. more...
- Published
- 2011
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21. Crystalline Hybrid Polyphenylene Macromolecules from Octaalkynylsilsesquioxanes, Crystal Structures, and a Potential Route to 3-D Graphenes
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Mark F. Roll, Richard M. Laine, and Jeffrey W. Kampf
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Polymers and Plastics ,biology ,Organic Chemistry ,Crystal structure ,Triclinic crystal system ,biology.organism_classification ,Silsesquioxane ,Scholl reaction ,Inorganic Chemistry ,chemistry.chemical_compound ,chemistry ,Tetraphenylcyclopentadienone ,Polymer chemistry ,Materials Chemistry ,Tetra ,Diphenylacetylene ,Hexaphenylbenzene - Abstract
We report here the Diels−Alder reaction of octa(diphenylacetylene)silsesquioxane [DPA8OS] with tetraphenylcyclopentadienone or tetra(p-tolyl)cyclopentadienone to form octa(hexaphenylbenzene)octasilsesquioxane, (Ph6C6)8OS, or octa(tetratolyldiphenylbenzene)octasilsesquioxane, (p-Tolyl4Ph2C6)8OS. Likewise, tetra(p-tolyl)cyclopentadienone reacts with octa(p-tolylethynylphenyl)OS to form octa(pentatolylphenylbenzene)octasilsesquioxane (p-Tolyl5PhC6)8OS. These compounds, with molecular weights of 4685−5245 Da, were isolated and characterized using a variety of analytical methods. The crystal structure of DPA8OS offers a 3 nm3 unit cell with Z = 1. The crystal structure of (Ph6C6)8OS was determined to have a triclinic unit cell of 11 nm3 with Z = 1. The latter structure is believed to be the largest discrete molecular structure reported with 330 carbons. Efforts to dehydrogenatively cyclize (Scholl reaction) the hexaarylbenzene groups to form 3-D octgraphene compounds are described. more...
- Published
- 2011
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22. Model Compounds Based on Cyclotriphosphazene and Hexaphenylbenzene with Tethered Li+-Solvents and Their Ion-Conducting Properties
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Wolfgang H. Meyer, Katharina Landfester, and Jörg Thielen
- Subjects
Materials science ,General Chemical Engineering ,Inorganic chemistry ,Ionic bonding ,chemistry.chemical_element ,General Chemistry ,Electrolyte ,Ion ,Solvent ,chemistry.chemical_compound ,chemistry ,Materials Chemistry ,Lithium ,Glass transition ,Hexaphenylbenzene ,Ethylene carbonate - Abstract
To improve the lithium ion conductivities of currently used electrolytes, it is critical to understand how the transport of the lithium ions within the matrix is influenced by their interactions with solvating moieties. Therefore, well-defined model compounds based on cyclotriphosphazene (CTP) and hexaphenylbenzene (HPB) cores were prepared, bearing side groups containing the structural element of ethylene carbonate, which is the common solvent for lithium salts used as electrolytes in Li-ion batteries. All model compounds were highly pure and thermally stable up to at least 250 °C, covering a broad range of glass transition temperatures from −79 °C up to +3.5 °C. The temperature-dependent ionic conductivities of the blends follow a William−Landel−Ferry (WLF) type behavior with the corresponding glass transition temperatures as reference. Though the glass transition temperatures of the blends are low, their conductivities are only in the range of typical polymer electrolytes, implying that the coordinatio... more...
- Published
- 2011
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23. New Hyperbranched Conjugated Polymers Containing Hexaphenylbenzene and Oxadiazole Units: Convenient Synthesis and Efficient Deep Blue Emitters for PLEDs Application
- Author
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Gu Yu, Shanghui Ye, Yunqi Liu, Wenbo Wu, Zhen Li, Zhong'an Li, and Jingui Qin
- Subjects
chemistry.chemical_classification ,Materials science ,Oxadiazole ,Polymer ,Conjugated system ,Surfaces, Coatings and Films ,chemistry.chemical_compound ,chemistry ,Polymerization ,Polymer chemistry ,Materials Chemistry ,Copolymer ,Thermal stability ,Light emission ,Physical and Theoretical Chemistry ,Hexaphenylbenzene - Abstract
In this article, four "A(3)+B(2)+C(2)"-type hyperbranched conjugated polymers (P1-P4) containing hexaphenylbenzene as the core were synthesized successfully for the first time with high yields through one-pot Suzuki polymerization reaction. The copolymerization percent of 1,3,4-oxadiazole units was adjusted to investigate the effect of polymer composition on the physical, optical, and EL properties. All polymers were well-characterized and exhibited good solubility, film-forming ability, and thermal stability. Both the solution and the films of these hyperbranched polymers emitted pure and stable deep-blue light emission, and their PL spectra did not change after annealing at 150 degrees C for 0.5 h in air, indicating that the hyperbranched structure, coupled to the introduced hexaphenylbenzene moieties, effectively suppressed the formation of aggregation excimer and keto defects. Two-layer PLED devices were fabricated to investigate the electroluminescence properties of these hyperbranched polymers, and P3 demonstrated a maximum luminance efficiency of 0.72 cd/A and a maximum brightness of 549 cd/m(2) at 16.5 V. more...
- Published
- 2010
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24. A Core-First Preparation of Poly(3-alkylthiophene) Stars
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Roman Tkachov, Nikolai Severin, Volodymyr Senkovskyy, Manfred Stamm, Anton Kiriy, Vera Bocharova, Albena Lederer, Hartmut Komber, Jürgen P. Rabe, and Tetyana Beryozkina
- Subjects
Materials science ,Condensation polymer ,Polymers and Plastics ,Atomic force microscopy ,Aryl ,Organic Chemistry ,Core (manufacturing) ,Condensed Matter Physics ,Catalysis ,chemistry.chemical_compound ,Star polymer ,chemistry ,Polymer chemistry ,Materials Chemistry ,Hexaphenylbenzene - Abstract
A new and facile method for the preparation of mono- and hexa-functional Ni-bipyridyl-based initiators that mediate Kumada polycondensation of 2 -bromo- 5 -chloromagnesio- 3 -hexylthiophene into head-to-tail regioregular poly(3-hexylthiophene), P 3 HT, has been developed. An important advantage of the catalytic system presented herein is the ease of the preparation of a number of Ar-Nibipy-Br initiators from readily available aryl halides. As an example, the "core-first" synthesis of 6-arm star-like P 3 HT having a hexaphenylbenzene core is demonstrated. more...
- Published
- 2010
- Full Text
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25. Ionomers for proton exchange membrane fuel cells by sulfonation of novel dendritic multiblock copoly(ether-sulfone)s
- Author
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Julie Gaudet, Daniel Guay, Allan S. Hay, Mohammed A. K. Al-Souz, Antisar R. Hlil, and Sumiko Matsumura
- Subjects
chemistry.chemical_classification ,Condensation polymer ,Polymers and Plastics ,Organic Chemistry ,Ether ,Sulfonic acid ,Sulfone ,chemistry.chemical_compound ,Membrane ,chemistry ,Nafion ,Polymer chemistry ,Materials Chemistry ,Sulfolane ,Hexaphenylbenzene - Abstract
The synthesis and properties of the first examples of dendritic multiblock coPESs, bearing sulfonated dendritic clusters, that form strong membranes are described. End-capped dendritic multiblock coPESs with various average block lengths (n = 50―80) were synthesized by two-step reactions. The synthesis of dendritic blocks consisting of difunctional dendritic block and monofunctional dendritic end-group was accomplished by an aromatic nucleophilic substitution reaction of hexakis(4-(4-fluorophenylsulfonyl)phenyl)benzene with varying amounts of 1-(4-hydroxyphenyl)-2,3,4,5,6-pentaphenylbenzene, which provides a number of pendant phenyl rings as postsulfonation sites. Polycondensation of a controlled molar ratio between 4,4'-dihydroxybenzophenone and bis(4-fluorophenyl)sulfone monomers was carried out in the presence of the difunctional and monofunctional dendritic blocks in sulfolane at 215 °C for 3.5 h. Essentially six sulfonic acid groups were introduced into each hexaphenylbenzene moiety on the dendritic blocks by reaction with a large excess of chlorosulfonic acid, followed by hydrolysis with KOH aqueous solution. The introduction of longer average blocks (n = 60―80) into the dendritic PESs improved the mechanical properties of the resulting sulfonated dendritic PES membranes. At a level of IEC (0.92―1.26 meq/g) similar to Nafion (0.91 meq/g), PES membranes showed proton conductivities (58―67 mS/cm) comparable with that of Nafion (99 mS/ cm). more...
- Published
- 2009
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26. Multiantenna Artificial Photosynthetic Reaction Center Complex
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Ana L. Moore, Gerdenis Kodis, Paul A. Liddell, Yuichi Terazono, Thomas A. Moore, Devens Gust, and Vikas Garg
- Subjects
Models, Molecular ,Photosynthetic reaction centre ,Time Factors ,Light ,Metalloporphyrins ,Porphobilinogen ,Photosynthetic Reaction Center Complex Proteins ,Molecular Conformation ,Quantum yield ,Electrons ,Photochemistry ,Absorption ,chemistry.chemical_compound ,Biomimetics ,Materials Chemistry ,Physical and Theoretical Chemistry ,Furans ,Hexaphenylbenzene ,Anthracenes ,chemistry.chemical_classification ,Physics::Biological Physics ,Spectrum Analysis ,Benzene ,Electron acceptor ,Chromophore ,Porphyrin ,Surfaces, Coatings and Films ,Energy Transfer ,chemistry ,Photoinduced charge separation ,Excited state ,Fullerenes - Abstract
In order to ensure efficient utilization of the solar spectrum, photosynthetic organisms use a variety of antenna chromophores to absorb light and transfer excitation to a reaction center, where photoinduced charge separation occurs. Reported here is a synthetic molecular heptad that features two bis(phenylethynyl)anthracene and two borondipyrromethene antennas linked to a hexaphenylbenzene core that also bears two zinc porphyrins. A fullerene electron acceptor self-assembles to both porhyrins via dative bonds. Excitation energy is transferred very efficiently from all four antennas to the porphyrins. Singlet-singlet energy transfer occurs both directly and by a stepwise funnel-like pathway wherein excitation moves down a thermodynamic gradient. The porphyrin excited states donate an electron to the fullerene with a time constant of 3 ps to generate a charge-separated state with a lifetime of 230 ps. The overall quantum yield is close to unity. In the absence of the fullerene, the porphyrin excited singlet state donates an electron to a borondipyrromethene on a slower time scale. This molecule demonstrates that by incorporating antennas, it is possible for a molecular system to harvest efficiently light throughout the visible from ultraviolet wavelengths out to approximately 650 nm. more...
- Published
- 2009
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27. Conformational dependence of tag induced intramolecular STM contrast in hexaphenylbenzene molecules
- Author
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André Gourdon, We-Hyo Soe, Christian Joachim, Abir De Sarkar, N. Chandrasekhar, and Carlos Manzano
- Subjects
Surfaces and Interfaces ,Condensed Matter Physics ,Quantum chemistry ,Surfaces, Coatings and Films ,law.invention ,chemistry.chemical_compound ,Crystallography ,Adsorption ,Physisorption ,chemistry ,Computational chemistry ,law ,Intramolecular force ,Materials Chemistry ,Molecule ,Self-assembly ,Scanning tunneling microscope ,Hexaphenylbenzene - Abstract
Chemically tagged hexaphenylbenzene molecules physisorbed on Au(1 1 1) surface display their tag differently under STM as compared to their physisorption on a Cu(1 1 1) surface. Our STM findings complemented by First Principles and Quantum Chemistry calculations have attributed this difference to two different conformations adopted by these molecules on Au(1 1 1) in comparison to its one conformation on Cu(1 1 1). The demonstration of the sensitivity of the tag to its electronic or chemical environment would have important implications in designing single molecule machinery where the motion of the molecule is to be discerned by tracking its tag induced intramolecular STM contrast. more...
- Published
- 2009
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28. The crystal structure of [Mo(NCS)(CO)2(η3-C3H5)(NCMe)2]·MeCN and the reactions of {Mo(CO)2(η3-C3H5)+} containing species with symmetric alkynes
- Author
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Brian J. Brisdon, Jonathan W Goodyear, Matthew R. Wiseman, Ross W. Harrington, and Clive W Hemingway
- Subjects
Thiocyanate ,Stereochemistry ,Ligand ,Organic Chemistry ,chemistry.chemical_element ,Crystal structure ,Biochemistry ,Medicinal chemistry ,Inorganic Chemistry ,Solvent ,chemistry.chemical_compound ,chemistry ,Molybdenum ,Materials Chemistry ,Methanol ,Physical and Theoretical Chemistry ,Acetonitrile ,Hexaphenylbenzene - Abstract
In the solid-state [Mo(NCS)(CO)2(η3-C3H5)(NCMe)2] · MeCN (1) contains a pseudo-octahedral arrangement of ligands about molybdenum, with carbonyls and nitriles in the equatorial plane and an N-bonded thiocyanate group trans to the allyl ligand. In refluxing methanol or acetonitrile both 1, and the analogous chloro-complex [MoCl(CO)2(η3-C3H5)(NCMe)2] (2) catalytically convert PhCCPh to a mixture of hexaphenylbenzene and E,E-1,2,3,4-tetraphenylbutadiene. By contrast MeO2CCCCO2Me is not oligomerised. In methanol, complex 2 dimerises 1,4-diphenylbutadiyne to Z,E-1,4,5,8-tetraphenyl-1,7-octa-3,5-diene-1,7-diyne, whereas in the presence of base both the complex and the diyne, react preferentially with the solvent to generate the [Mo2(CO)4(η3-C3H5)2(OMe)3]− anion and Z-1,4-diphenyl-3-methoxy-but-3-ene-1-yne, respectively. more...
- Published
- 2002
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29. A hexaphenylbenzene based AIEE active probe for the preparation of ferromagnetic α-Fe2O3 nanoparticles: facile synthesis and catalytic applications
- Author
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Manoj Kumar, Subhamay Pramanik, and Vandana Bhalla
- Subjects
Materials science ,chemistry.chemical_element ,Sonogashira coupling ,Nanoparticle ,Photochemistry ,Ferric Compounds ,Coupling reaction ,Catalysis ,chemistry.chemical_compound ,Materials Chemistry ,Rhodamine B ,Amines ,Magnetite Nanoparticles ,Hexaphenylbenzene ,Photolysis ,Rhodamines ,Metals and Alloys ,Temperature ,General Chemistry ,Surfaces, Coatings and Films ,Electronic, Optical and Magnetic Materials ,chemistry ,Ceramics and Composites ,Amine gas treating ,Copper ,Palladium - Abstract
Fluorescent aggregates formed by self-assembly of a hexaphenylbenzene based derivative 3 serve as a reactor and a stabilizer for the formation of ferromagnetic iron oxide (α-Fe2O3) nanoparticles in aqueous medium at room temperature. These α-Fe2O3 nanoparticles showed excellent catalytic activity in palladium, copper and amine free Sonogashira cross coupling reactions and also in photocatalytic degradation of rhodamine B dye. more...
- Published
- 2014
30. Starlike substituted hexaarylbenzenes: synthesis and mesomorphic properties
- Author
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Yanhou Geng, Klaus Müllen, and Andreas Fechtenkötter
- Subjects
Polarized light microscopy ,Stereochemistry ,Aryl ,Mesophase ,General Chemistry ,chemistry.chemical_compound ,Crystallography ,Differential scanning calorimetry ,chemistry ,Liquid crystal ,Materials Chemistry ,Side chain ,Thiophene ,Hexaphenylbenzene - Abstract
A series of hexaarylbenzenes (1–6) with a variety of different aryl arms (i.e. phenyl, biphenylyl, mono-, bi-, and terthienylyl) around a benzene core, decorated with flexible dodecyl chains on the terminal positions, were synthesized. Their mesomorphic behaviors were studied by differential scanning calorimetry (DSC), polarizing optical microscopy (POM) and X-ray diffraction (XD) techniques. Compounds 1–3, which have a hexaphenylbenzene core, form columnar mesophases. In particular 3, in which the core is composed of hexaphenylbenzene surrounded by thiophene rings, shows a stable columnar mesophase (d-Dh) over a large temperature range compared to its phenyl analogs, hexakis(4-dodecylphenyl-4-yl)benzene (1) and hexakis(4′-dodecylbiphenylyl)benzene (2). Compounds 4–6, hexa(oligo-α-thienylyl)benzenes, tend to form less ordered mesophases after annealing for a longer time. Compounds 4 and 5 form discotic nematic mesophases (Nd) at temperatures well below the decomposition temperature. more...
- Published
- 2001
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31. Synthesis and properties of copolymers from diphenylacetylene having a hexaphenylbenzene moiety
- Author
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Andreas Fechtenkötter, Masahiro Teraguchi, Klaus Müllen, and Toshio Masuda
- Subjects
Steric effects ,Polymers and Plastics ,Trimethylsilyl ,General Chemistry ,Condensed Matter Physics ,Toluene ,chemistry.chemical_compound ,chemistry ,Acetylene ,Polymer chemistry ,Materials Chemistry ,Copolymer ,Moiety ,Hexaphenylbenzene ,Diphenylacetylene - Abstract
Copolymerization of diphenylacetylene having a hexaphenylbenzene group, 1-[p-(pentaphenyl)phenyl]-2-phenylacetylene (1), with a few other diphenylacetylene derivatives (i.e., diphenylacetylene, 1-phenyl-2-[(trimethylsilyl)phenyl]acetylene, 1-phenyl-2-[p-n-octylphenyl]acetylene, (2a-c, respectively) and properties of the formed copolymers were investigated. No polymer was obtained in homopolymerization of 1 with TaCl 5 -n-Bu 4 Sn catalyst owing to steric hindrance. On the other hand, copolymerization with 2a-c proceeded at various feed ratios to give copolymers in moderate yields. Copoly(1/2a) (feed ratio 25/75) was soluble in toluene and CHCl 3 and its weight-average molecular weight (M w ) was ca. 31x10 4 and relatively high. Copoly(1/2b) and copoly(1/2c) (both feed ratios 5/95) were soluble in common organic solvents, and had a large M w up to ca. 1x10 6 . These copolymers were yellow to orange solids. Oxidative cyclodehydrogenation of hexaphenylbenzene groups in copoly(1/2a) was attempted in order to convert them into more conjugated groups. more...
- Published
- 2000
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32. Bis[(η8-cyclooctatetraene)titanium] complex with perpendicularly bridging bis(trimethylsilyl)acetylene
- Author
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Karel Mach, Jörg Hiller, Michal Horáček, Petr Štěpnička, and Ulf Thewalt
- Subjects
Trimethylsilyl ,Chemistry ,Organic Chemistry ,Crystal structure ,Photochemistry ,Biochemistry ,Inorganic Chemistry ,chemistry.chemical_compound ,Cyclooctatetraene ,Crystallography ,Acetylene ,Bis(trimethylsilyl)acetylene ,Materials Chemistry ,Thermal stability ,Physical and Theoretical Chemistry ,Diphenylacetylene ,Hexaphenylbenzene - Abstract
The reduction of [(η8-C8H8)Ti(THF)(μ-Cl)]2 by magnesium in the presence of bis(trimethylsilyl)acetylene (BTMSA) afforded the diamagnetic complex [(η8-C8H8)Ti]2[μ-η2:η2-Me3SiCCSiMe3] (1) in high yield. The crystal structure of 1 revealed that BTMSA is a four-electron ligand which binds two equivalent (η8-C8H8)Ti moieties under the angle of av. 69°. The average CC distance of 1.51 A in the acetylene ligand is close to that of sp3 carbon atoms, however, a high thermal stability and enormously large down-field chemical shift of the acetylenic carbon atoms (δ 292.8 ppm) points to an unusually high contribution of π-back-bonding to the Ti-acetylene bond. An analogous reduction in the presence of diphenylacetylene afforded a tetraphenylcyclobutadiene complex (η8-C8H8)Ti(η4-C4Ph4) and hexaphenylbenzene. more...
- Published
- 1998
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33. Poly(4‘-vinylhexaphenylbenzene)s: New Carbon-Rich Polymers
- Author
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Klaus Müllen, Shu-Ling Chen, and Christian Kübel
- Subjects
chemistry.chemical_classification ,integumentary system ,Polymers and Plastics ,Chemistry ,fungi ,Organic Chemistry ,Radical polymerization ,food and beverages ,chemistry.chemical_element ,Chemical modification ,Soluble polymer ,Polymer ,Inorganic Chemistry ,chemistry.chemical_compound ,Polymer chemistry ,Materials Chemistry ,Organic chemistry ,Carbon ,Hexaphenylbenzene - Abstract
Poly(4‘-vinylhexaphenylbenzene) is a new, readily soluble polymer with hexaphenylbenzene side groups. The hexaphenylbenzene moieties can be cyclodehydrogenated oxidatively with CuCl2/AlCl3 yielding... more...
- Published
- 1998
- Full Text
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34. Cyanide modulated fluorescent supramolecular assembly of a hexaphenylbenzene derivative for detection of trinitrotoluene at the attogram level
- Author
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Vandana Bhalla, Subhamay Pramanik, and Manoj Kumar
- Subjects
Detection limit ,Cyanide ,Metals and Alloys ,General Chemistry ,Photochemistry ,Fluorescence ,Catalysis ,Surfaces, Coatings and Films ,Electronic, Optical and Magnetic Materials ,Supramolecular assembly ,chemistry.chemical_compound ,chemistry ,Materials Chemistry ,Ceramics and Composites ,Trinitrotoluene ,Nanorod ,Hexaphenylbenzene ,Derivative (chemistry) - Abstract
Fluorescent nanorods formed by self-assembly of hexaphenylbenzene derivative in the presence of cyanide ions serve as a sensitive colorimetric and fluorogenic sensor for the detection of trinitrotoluene (TNT) at the attogram (10(-18) g) level with a detection limit of 10.21 ppq (parts per quadrillion). more...
- Published
- 2012
35. Hexaphenylbenzene-based polymers of intrinsic microporosity
- Author
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Neil B. McKeown, Mariolino Carta, C. Grazia Bezzu, Benson M. Kariuki, Rhys Short, and Detlev Fritsch
- Subjects
chemistry.chemical_classification ,Molar mass ,Metals and Alloys ,General Chemistry ,Polymer ,Microporous material ,Catalysis ,Surfaces, Coatings and Films ,Electronic, Optical and Magnetic Materials ,chemistry.chemical_compound ,Adsorption ,chemistry ,Permeability (electromagnetism) ,Polymer chemistry ,Materials Chemistry ,Ceramics and Composites ,Molecule ,Hexaphenylbenzene ,ddc:620.11 - Abstract
Microporous polymers derived from the 1,2- and 1,4-regioisomers of di(3′,4′-dihydroxyphenyl)tetraphenylbenzene have very different properties with the former being composed predominantly of cyclic oligomers whereas the latter is of high molar mass suitable for the formation of robust solvent-cast films of high gas permeability. more...
- Published
- 2011
- Full Text
- View/download PDF
36. Engineering molecular crystals with abnormally weak cohesion
- Author
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James D. Wuest, Kenneth E. Maly, and Eric Gagnon
- Subjects
Metals and Alloys ,Nanotechnology ,General Chemistry ,Catalysis ,Surfaces, Coatings and Films ,Electronic, Optical and Magnetic Materials ,chemistry.chemical_compound ,chemistry ,Chemical physics ,Materials Chemistry ,Ceramics and Composites ,Cohesion (chemistry) ,Sublimation (phase transition) ,Hexaphenylbenzene - Abstract
Adding astutely placed methyl groups to hexaphenylbenzene increases molecular weight but simultaneously weakens key C-H···π interactions, thereby leading to decreased enthalpies of sublimation and showing that materials with abnormally weak cohesion can be made by identifying and then obstructing interactions that help control association. more...
- Published
- 2011
37. C60-induced alkyne-alkyne coupling and alkyne scission reactions of a tungsten tris(diphenylacetylene) complex
- Author
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Wen-Yann Yeh
- Subjects
chemistry.chemical_classification ,Tris ,Nitrile ,Stereochemistry ,Metals and Alloys ,Alkyne ,chemistry.chemical_element ,General Chemistry ,Tungsten ,Medicinal chemistry ,Catalysis ,Surfaces, Coatings and Films ,Electronic, Optical and Magnetic Materials ,chemistry.chemical_compound ,chemistry ,Materials Chemistry ,Ceramics and Composites ,Diphenylacetylene ,Hexaphenylbenzene ,Bond cleavage - Abstract
Reaction of W(NCMe)(η(2)-PhC≡CPh)(3) with C(60) affords W(η(3)-NC(Me)C(60))(η(4),η(2)-C(6)Ph(6)) (2) and W(≡CPh)(NCMe)(η(2)-C(60)) (η(3),η(2)-C(5)Ph(5)) (3). The hexaphenylbenzene species of 2 shows an η(4)-butadiene + η(2)-olefin bonding mode and the nitrile carbon is inserted into one 6:5-ring junction of C(60). Compound 3 contains an η(3),η(2)-pentaphenylcyclopentadienyl and a benzylidyne group from 2 + 2 + 1 cyclization and scission reactions of the diphenylacetylene ligands. more...
- Published
- 2010
38. Preparation of a tetraphenylethylene-based emitter: synthesis, structure and optoelectronic properties of tetrakis(pentaphenylphenyl)ethylene
- Author
-
Vijay S. Vyas and Rajendra Rathore
- Subjects
Steric effects ,Ethylene ,Materials science ,Metals and Alloys ,General Chemistry ,Tetraphenylethylene ,Photochemistry ,Catalysis ,Surfaces, Coatings and Films ,Electronic, Optical and Magnetic Materials ,Turn (biochemistry) ,chemistry.chemical_compound ,chemistry ,Polymer chemistry ,Materials Chemistry ,Ceramics and Composites ,Hexaphenylbenzene ,Common emitter - Abstract
Soluble tetrakis(pentaphenylphenyl)ethylene (1), prepared in three steps, allows non-emissive tetraphenylethylene (TPE) to turn into an emitter (Phi(F) = 0.13) owing to the steric bulk of the four large hexaphenylbenzene propellers which hamper =C-Ph and C=C bond rotations in the TPE core. more...
- Published
- 2010
39. The fluxional behaviour of hexaphenylbenzene chromium tricarbonyl: A variable-temperature 13C NMR spectroscopic study
- Author
-
Brian G. Sayer, Bavani Mailvaganam, and Michael J. McGlinchey
- Subjects
Stereochemistry ,Organic Chemistry ,chemistry.chemical_element ,Activation energy ,Nuclear magnetic resonance spectroscopy ,Carbon-13 NMR ,Ring (chemistry) ,Biochemistry ,Inorganic Chemistry ,Metal ,Chromium ,Crystallography ,chemistry.chemical_compound ,chemistry ,visual_art ,Materials Chemistry ,visual_art.visual_art_medium ,Molecule ,Physical and Theoretical Chemistry ,Hexaphenylbenzene - Abstract
The 125 MHz 13C NMR spectrum of (C6Ph6)Cr(CO)3 reveals that the metal is π-bonded to a peripheral ring. At −80°C this chromium-bonded phenyl exhibits slowed rotation on the NMR time-scale and is effectively orthogonal to the central ring. The fluxional process is shown to involve rotation of the Cr(CO)3-complexed phenyl ring; the activation energy barrier is ≈ 12.2 kcal mol−1, a value much lower than those previously reported for non-complexed hexa-aryl benzenes bearing ortho or meta methyl or methoxy substituents. more...
- Published
- 1990
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40. HBC–porphyrin – close contact chromophores
- Author
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Jan M. Englert, Jenny Malig, Valeria Anna Zamolo, Andreas Hirsch, and Norbert Jux
- Subjects
Porphyrins ,010405 organic chemistry ,Chemistry ,Metals and Alloys ,General Chemistry ,Chromophore ,010402 general chemistry ,Photochemistry ,01 natural sciences ,Porphyrin ,Catalysis ,0104 chemical sciences ,3. Good health ,Surfaces, Coatings and Films ,Electronic, Optical and Magnetic Materials ,Connection (mathematics) ,chemistry.chemical_compound ,Materials Chemistry ,Ceramics and Composites ,Polycyclic Compounds ,Spectrophotometry, Ultraviolet ,Nuclear Magnetic Resonance, Biomolecular ,Close contact ,Hexaphenylbenzene ,Conjugate - Abstract
A photo/redoxactive hexa-peri-hexabenzocoronene-porphyrin conjugate with a direct connection between the two chromophores was synthesised using a formylated hexaphenylbenzene precursor.
- Published
- 2013
- Full Text
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41. Hexaphenylphenylene dendronised pyrenylamines for efficient organic light-emitting diodes
- Author
-
Jiann T. Lin, Chang-Hao Chuen, Yu-Tai Tao, K. R. Justin Thomas, and Marappan Velusamy
- Subjects
chemistry.chemical_element ,General Chemistry ,Electroluminescence ,Photochemistry ,chemistry.chemical_compound ,Differential scanning calorimetry ,chemistry ,Materials Chemistry ,OLED ,Cyclic voltammetry ,Thin film ,Layer (electronics) ,Hexaphenylbenzene ,Palladium - Abstract
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 differential scanning calorimetry and facile reversible oxidation couple in cyclic voltammetry. They are also thermally stable exhibiting decomposition temperature above 385 °C. Efficient blue-emitting electroluminescent devices were fabricated using these novel amines as the hole transporting layer and 1,3,5-tris(N-phenylbenzimidazol-2-yl)benzene (TPBI) as the electron transporting layer. Colour mixing or green emission was observed when tris(8-hydroxyquinoline)aluminium (Alq3) was used as the electron transporting layer. However insertion of a thin layer of TPBI or 1,3,5-tris(4-tert-butylphenyl-1,3,4-oxadiazolyl)benzene (TPOB) in between the HTL and Alq3 layers led to pure blue emission owing to the confinement of recombination inside the HTL layer containing the compounds. more...
- Published
- 2005
- Full Text
- View/download PDF
42. Interaction of diphenylacetylene with chromium salts
- Author
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L. P. Yur'eva, N.V. Zakurin, A. Yu. Vasil’kov, N. N. Zaitseva, and N. I. Vasyukova
- Subjects
Inorganic Chemistry ,chemistry.chemical_compound ,Chromium ,chemistry ,Stereochemistry ,Organic Chemistry ,Polymer chemistry ,Materials Chemistry ,chemistry.chemical_element ,Physical and Theoretical Chemistry ,Biochemistry ,Diphenylacetylene ,Hexaphenylbenzene - Abstract
The reaction of diphenylacetylene with chromium atoms results in the formation of bisarenechromium π-complexes containing diphenylacetylene and its cyclotrimer as ligands, viz., bis(η 6 -diphenylacetylene)chromium, (η 6 -diphenylacetylene)(η 6 -hexaphenylbenzene)chromium and bis(η 6 -hexaphenylbenzene)chromium. The other reaction products were found to be uncomplexed hexaphenylbenzene and 1,2,3,4-tetraphenylbutadiene-1,3. more...
- Published
- 1983
- Full Text
- View/download PDF
43. The role of nickelole intermediates in the oligomerization of alkynes
- Author
-
James E. Galle and John J. Eisch
- Subjects
Dimethyl acetylenedicarboxylate ,Organic Chemistry ,Reactive intermediate ,chemistry.chemical_element ,Biochemistry ,Medicinal chemistry ,Catalysis ,Inorganic Chemistry ,Nickel ,chemistry.chemical_compound ,chemistry ,Reagent ,Materials Chemistry ,Organic chemistry ,Physical and Theoretical Chemistry ,Triphenylphosphine ,Diphenylacetylene ,Hexaphenylbenzene - Abstract
Bis(triphenylphosphine)nickel(II) chloride reacts with E,E, -1,4-dilithio-1,2,3,4-tetraphenylbutadiene to yield a solution of a 2,3,4,5-tetraphenylnickelole complex. This compound reacts promptly with CO to yield tetracyclone, with dimethyl acetylenedicarboxylate to form dimethyl tetraphenylphthalate and catalytically with diphenylacetylene to form hexaphenylbenzene. A similar treatment of (1,2-bis(diphenylphosphino)ethane)nickel(II) chloride with the lithium reagent led to the isolation of (1,2-bis(diphenylphosphino)ethane)bis(2,3,4,5-tetraphenylnickelole), which likewise reacts with dimethyl acetylenedicarboxylate to yield dimethyl tetraphenylphthalate. These results support the interpretation that nickeloles are reactive intermediates in the cyclotrimerization of alkynes by nickel(0) catalysts. more...
- Published
- 1975
- Full Text
- View/download PDF
44. Tricarbonylchromium(0) complexes of 1,3,5-triphenylbenzene: an X-ray crystallographic and high field NMR spectroscopic study
- Author
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Bavani Mailvaganam, Brian E. McCarry, Romolo Faggiani, Michael J. McGlinchey, Brian G. Sayer, and Richard E. Perrier
- Subjects
Aryl ,Organic Chemistry ,Nuclear magnetic resonance spectroscopy ,Crystal structure ,Carbon-13 NMR ,Dihedral angle ,Ring (chemistry) ,Biochemistry ,Inorganic Chemistry ,Crystallography ,chemistry.chemical_compound ,chemistry ,Materials Chemistry ,Proton NMR ,Physical and Theoretical Chemistry ,Hexaphenylbenzene - Abstract
The reaction of 1,3,5-triphenylbenzene (TPB) with Cr(CO) 6 yields products in which a Cr(CO) 3 moiety is bonded to the central ring or to one, two or all three peripheral phenyl rings. The structure of the TPB · 3Cr(CO) 3 complex has been determined by single crystal X-ray diffraction techniques. The complex crystallizes in the space group P 2 1 / n with unit cell parameters a 8.316(2) A, b 15.498(5) A, c 22.254(4) A, β 92.18(2)°, V 2865.8(11) A 3 and Z = 4. The structure has been solved by direct and Fourier methods and refined by block diagonal matrix least squares to R 1 and R 2 values of 0.053 and 0.053, respectively, for 2830 observed reflections. The structure reveals that the chromium tricarbonyl groups are bonded to the three peripheral phenyls and these aryl rings adopt dihedral angles of 35° −26° and 14° with respect to the central ring; these dihedral angles are remarkably similar to those in the free ligand itself. All three Cr(CO) 3 tripods are oriented to within a few degrees of being perfectly staggered with respect to the aryl carbon atoms. The 500 MHz 1 H and 125 MHz 13 C NMR spectra of these complexes reveal that the peripheral rings do not exhibit restricted rotation even at −90°C. This contrasts with the situation for (hexaphenylbenzene)Cr(CO) 3 the 1 H NMR spectrum of which may indicate slowed rotation of the phenyl rings even at room temperature. more...
- Published
- 1987
- Full Text
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45. Some reactions of tetrabenzylvanadium
- Author
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V.K. Cherkasov, V.N. Latyaeva, V.V. Drobotenko, L.I. Vyshinskaja, A.N. Linyova, and G.A. Razuvaev
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Cyclopentadiene ,Chemistry ,Organic Chemistry ,Thermal decomposition ,Vanadium ,chemistry.chemical_element ,Photochemistry ,Biochemistry ,Decomposition ,Inorganic Chemistry ,chemistry.chemical_compound ,Acetylene ,Differential thermal analysis ,Polymer chemistry ,Materials Chemistry ,Physical and Theoretical Chemistry ,Diethyl ether ,Hexaphenylbenzene - Abstract
The thermal decomposition of tetrabenzylvanadium has been studied with the help of differential thermal analysis (DTA) and the decomposition products identified. The reaction of tetrabenzylvanadium with acetylene and cyclopentadiene proceeds with displacement of four benzyl groups with formation of toluene. As a result of the interaction of tetrabenzylvanadium with tolan bis(hexaphenylbenzene)vanadium was isolated. The ESR spectra of tetrabenzylvanadium and its decomposition products, in the temperature range from −178 to +20°C, have been studied in diethyl ether. more...
- Published
- 1975
- Full Text
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46. The synthesis and molecular structure of π-cyclopentadienyl-π-tetraphenylcyclobutadienerhodium(I)
- Author
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Gordon G. Cash, John F. Helling, M. Mathew, and Gus J. Palenik
- Subjects
Organic Chemistry ,chemistry.chemical_element ,Crystal structure ,Ring (chemistry) ,Biochemistry ,Rhodium ,Inorganic Chemistry ,chemistry.chemical_compound ,Crystallography ,chemistry ,Cyclopentadienyl complex ,Materials Chemistry ,Molecular symmetry ,Physical and Theoretical Chemistry ,Diphenylacetylene ,Hexaphenylbenzene ,Monoclinic crystal system - Abstract
The reaction of π-cyclopentadienyl-π-1,5-cyclooctadienerhodium(I) and diphenylacetylene gives hexaphenylbenzene as the principal product with a low yield of π-cyclopentadienyl-π-tetraphenylcyclobutadienerhodium(I). The crystal structure of π-cyclopentadienyl-π-tetraphenylcyclobutadienerhodium(I) was determined by X-ray diffraction techniques using diffractometer data. The crystals are monoclinic with unit cell dimensions of a =13.416(3), b =19.534(6), c =13.411(2) A and β=135.01 (1)°. The space group is P 2 1 / c and, with four molecules per unit cell, no molecular symmetry is required ( D m =1.40 g/cm 3 and D c =1.411 g/cm 3 ). The structure was solved by the heavy atom method and refined by least-squares methods to a final R of 0.043 for the 3675 observed reflections used in the analysis. The rhodium atom is coordinated to both the cyclopentadienyl group (Rh-ring distance is 1.868 A) and the tetraphenylcyclobutadiene group (Rh-ring distance is 1.828 A). The phenyl groups are twisted relative to the C 4 ring and bent away from the rhodium atom. more...
- Published
- 1973
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47. Cyclization of diphenylacetylene on methylchromium σ-complexes II. Cyclic and linear condensations
- Author
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H.H. Zeiss and M. Michman
- Subjects
CHROMIUM COMPLEX ,Chemistry ,Stereochemistry ,Organic Chemistry ,Condensation ,Ring (chemistry) ,Biochemistry ,Medicinal chemistry ,Inorganic Chemistry ,chemistry.chemical_compound ,Materials Chemistry ,Physical and Theoretical Chemistry ,Methylene ,Carbene ,Diphenylacetylene ,Hexaphenylbenzene - Abstract
The reactions of diphenylacetylene with methylchromium systems lead to the formation of condensation products, of which the following have been isolated and identified: cis , cis -1,2,3,4-tetraphenyl-1,3-butadiene; hexaphenylbenzene; 1,2,3-triphenylnaphthalene: 1-methyl-2,3,4-triphenylnaphthalene: 1,2,3,4-tetraphenyl-1,3-cyclopentadiene and 1,2,4,5-tetraphenylbenzene. It is evident that methyl groups of the chromium complex participate in these cyclic condensations via insertions of methylene (carbene) groups into the ring skeleton. These processes are also accompanied by hydrogen-transfer reactions. more...
- Published
- 1970
- Full Text
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48. Cyclooctatetraene(tetraphenylcyclobutadiene)titanium
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H.O. Van Oven
- Subjects
Ligand ,Organic Chemistry ,chemistry.chemical_element ,Ether ,Photochemistry ,Biochemistry ,Inorganic Chemistry ,chemistry.chemical_compound ,Cyclooctatetraene ,chemistry ,Materials Chemistry ,Mass spectrum ,Diamagnetism ,Physical and Theoretical Chemistry ,Hexaphenylbenzene ,Diphenylacetylene ,Titanium - Abstract
The compound C8H8TiC4(C6H5)4 has been prepared by reaction of TiCl3 and i-C3H7MgBr in ether in the presence of cyclooctatetraene and diphenylacetylene. The green compound is diamagnetic and stable in the air in the solid state. IR, NMR and mass spectra show the presence of a π-bonded tetraphenylcyclobutadiene and a π-bonded cyclooctatetraene ligand in the complex. A by-product in the synthesis is hexaphenylbenzene. more...
- Published
- 1973
- Full Text
- View/download PDF
49. Metallostars and metallodendrimers based upon hexaphenylbenzene cores
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Catherine E. Housecroft, Oliver Eich, and Edwin C. Constable
- Subjects
Inorganic Chemistry ,chemistry.chemical_classification ,chemistry.chemical_compound ,chemistry ,Dendrimer ,Materials Chemistry ,Cluster (physics) ,Alkyne ,Physical and Theoretical Chemistry ,Photochemistry ,Hexaphenylbenzene - Abstract
Stars and dendrimers based on a hexaphenylbenzene core and containing 12 or 30 alkyne functionalities have been prepared; reactions with Co2(CO)8 lead to cobaltadendrimers containing 24 or 60 Co atoms. more...
50. Acetylenic derivatives of metal carbonyls. XIV. Cyclotrimerization of diphenylacetylene with dodecarbonyltriosmium
- Author
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Gian Angelo Vaglio, Olimpia Gambino, Rosa Pia Ferrari, and G. Cetini
- Subjects
Chemistry ,Ligand ,Stereochemistry ,Thermal decomposition ,Metal carbonyl ,Inorganic Chemistry ,chemistry.chemical_compound ,Physical chemical ,Yield (chemistry) ,Materials Chemistry ,Molecule ,Physical and Theoretical Chemistry ,Diphenylacetylene ,Hexaphenylbenzene - Abstract
L 2 Os 3 (CO) s complexes, where L = (C 6 H 5 ) 2 C 2 , ( p -ClC 6 H 4 ) 2 ( p -CH 3 C 6 H 4 ) 2 C 2 , react with excess of ligand to yield compounds of general formula L 3 Os 3 (CO) 7 . On the basis of chemical and physical chemical data, a structure is suggested in which only two ligand molecules are linked together. [(C 6 H 5 ) 2 ] 3 Os 3 (CO) 7 reacts with more diphenylacethylene to form hexaphenylbenzene. In the course of this process [C 6 H 5 ) 2 C 2 ] 3 Os 3 (CO) 6 can be isolated. This seems to be the last stable trinuclear intermediate in the cyclotrimerization reaction and seems to contain the three ligand molecules joined together. It does in fact give hexaphenylbenzene readily by thermal decomposition. more...
- Published
- 1973
- Full Text
- View/download PDF
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