The Experts below are selected from a list of 1209 Experts worldwide ranked by ideXlab platform
Jian Jin - One of the best experts on this subject based on the ideXlab platform.
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cis trans driven organized reorientation of an Azobenzene Derivative monolayer at the liquid graphite interface
New Journal of Chemistry, 2003Co-Authors: Jian Jin, Wensheng Yang, Yingying Zhao, Lei JiangAbstract:An Azobenzene Derivative, 2-hydroxy-4,4′-dihexyloxyAzobenzene, in which a hydroxy group is introduced at the 2-position of the phenyl ring, forms an ordered monolayer at the liquid/graphite interface. Upon light irradiation, this monolayer can undergo a reversible cis-trans driven cooperative reorientation as observed by scanning tunneling microscopy.
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molecular organization and electric property of Azobenzene Derivative at liquid graphite interface studied by scanning tunneling microscopy
Colloids and Surfaces A: Physicochemical and Engineering Aspects, 2002Co-Authors: Jian Jin, Yanjie Zhang, Wensheng Yang, Xia Chen, Yanlin Song, Yingying Zhao, Yubai Bai, Lei JiangAbstract:Topography and electric property of the physisorbed monolayer of an Azobenzene Derivative, 4,4′-dihexyloxy-2-hydroxy-Azobenzene (Azo), at the liquid/graphite interface were investigated by scanning tunneling microscopy (STM). The STM observations show that the Azobenzene Derivative can form an ordered row-like structure at the interface and the periodicity of the row is 3.0 nm, corresponding to the length of the molecule. Electric property of this organic tunnel junction at the liquid/graphite interface was examined by the measurement of the current–voltage (I–V) curve. The I–V curve is asymmetric for positive and negative voltages, indicating the rectifying behavior of the adlayer.
Lei Jiang - One of the best experts on this subject based on the ideXlab platform.
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cis trans driven organized reorientation of an Azobenzene Derivative monolayer at the liquid graphite interface
New Journal of Chemistry, 2003Co-Authors: Jian Jin, Wensheng Yang, Yingying Zhao, Lei JiangAbstract:An Azobenzene Derivative, 2-hydroxy-4,4′-dihexyloxyAzobenzene, in which a hydroxy group is introduced at the 2-position of the phenyl ring, forms an ordered monolayer at the liquid/graphite interface. Upon light irradiation, this monolayer can undergo a reversible cis-trans driven cooperative reorientation as observed by scanning tunneling microscopy.
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molecular organization and electric property of Azobenzene Derivative at liquid graphite interface studied by scanning tunneling microscopy
Colloids and Surfaces A: Physicochemical and Engineering Aspects, 2002Co-Authors: Jian Jin, Yanjie Zhang, Wensheng Yang, Xia Chen, Yanlin Song, Yingying Zhao, Yubai Bai, Lei JiangAbstract:Topography and electric property of the physisorbed monolayer of an Azobenzene Derivative, 4,4′-dihexyloxy-2-hydroxy-Azobenzene (Azo), at the liquid/graphite interface were investigated by scanning tunneling microscopy (STM). The STM observations show that the Azobenzene Derivative can form an ordered row-like structure at the interface and the periodicity of the row is 3.0 nm, corresponding to the length of the molecule. Electric property of this organic tunnel junction at the liquid/graphite interface was examined by the measurement of the current–voltage (I–V) curve. The I–V curve is asymmetric for positive and negative voltages, indicating the rectifying behavior of the adlayer.
Klaus Mullen - One of the best experts on this subject based on the ideXlab platform.
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green light triggered phase transition of Azobenzene Derivatives toward reversible adhesives
Journal of the American Chemical Society, 2019Co-Authors: Zhen Wu, Chendong Ji, Xujie Zhao, Klaus MullenAbstract:Studies on the Azobenzene Derivative based phase transitions mostly rely on photoisomerization, which require a long time to spontaneously revert back. Here we show a photothermal-driven solid-to-liquid transition and fast reversion of Azobenzene Derivatives. Owing to the aggregation of suitably substituted Azobenzenes, solid-to-liquid transitions can be induced by photothermal effects under irradiation with green light. The liquid-state Azobenzene Derivatives spontaneously solidify again within 2 min due to heat release in a purely physical fashion. One thus obtains a perfectly reversible adhesion with a strength as high as that of commercial materials. Our work affords a novel concept to construct reversible adhesives via phase transitions of organic compounds induced by light.
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Switchable dielectric permittivity with temperature and Dc-bias in a semifluorinated Azobenzene Derivative
Colloid and Polymer Science, 2014Co-Authors: René Stangenberg, Klaus Mullen, Christos Grigoriadis, Hans-jürgen Butt, George FloudasAbstract:The thermodynamic, optical, structural, and dynamic properties of the semifluorinated (E)-1-(4-octylphenyl)-2-(4-(perfluorooctyl)phenyl)diazene ( 4 ) and the corresponding (E)-1,2-bis(4-octylphenyl)diazene ( 5 ) have been studied with differential scanning calorimetry, polarizing optical microscopy, X-ray diffraction, and dielectric spectroscopy. 4 combines the Azobenzene properties with the fluorophobic effect and gives rise to a responsive material with a temperature and dc-bias-driven switchable dielectric permittivity within the narrower nematic phase. This is caused by the nematic potential that inevitably brings some fluorocarbon chains in proximity to the hydrocarbon chains from adjacent molecules. Frustration is alleviated by reducing the nematic-to-isotropic transition temperature and by increasing the crystalline-to-nematic transition temperature, thus limiting the stability of the nematic phase. Unlike the normal isotropic phase of compound 5 , the isotropic phase of compound 4 contains dipoles with short-range orientation correlations. Optimizing the type of interactions may result in materials with applications as molecular switches and electrooptic devices.
Davide Bonifazi - One of the best experts on this subject based on the ideXlab platform.
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Photoactive Boron-Nitrogen-Carbon Hybrids: From Azo-borazines to Polymeric Materials
Journal of Organic Chemistry, 2019Co-Authors: Hamid Oubaha, Nicola Demitri, Joelle Rault-berthelot, Philippe Dubois, Olivier Coulembier, Davide BonifaziAbstract:In this paper, we describe synthetic routes for preparing a novel switchable BNC-based chromophore, composed of a borazine core peripherally functionalized with Azobenzene moieties. Capitalizing on the Pd-catalyzed Suzuki cross-coupling reaction between a tris-triflate borazine and an organoboron Azobenzene Derivative, a photoswtichable azo-borazine Derivative was successfully prepared. The molecule showed reversible E/Z photoisomerization upon irradiation at the maximum of the intense π–π* absorption feature (360 nm). X-ray crystallographic investigations revealed a nonplanar orientation of the three Azobenzene moieties and the trans configuration of the −N═N– bonds. Building on the synthetic versatility of the borazine-Azobenzene Derivative, we used this photoactive scaffold to engineer soluble BN-doped polythiophene polymers. Photophysical characterization performed in solvents of different polarity suggested that the polymer undergoes intramolecular charge transfer (ICT).
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Toward Fractioning of Isomers through Binding-Induced Acceleration of Azobenzene Switching
2017Co-Authors: Rosaria Vulcano, Paolo Pengo, Simone Velari, Johan Wouters, Alessandro De Vita, Paolo Tecilla, Davide BonifaziAbstract:The E/Z isomerization process of a uracil–Azobenzene Derivative in which the nucleobase is conjugated to a phenyldiazene tail is studied in view of its ability to form triply H-bonded complexes with a suitably complementary 2,6-diacetylamino-4-pyridine ligand. UV–vis and 1H NMR investigations of the photochemical and thermal isomerization kinetics show that the thermal Z → E interconversion is 4-fold accelerated upon formation of the H-bonded complex. DFT calculations show that the formation of triple H-bonds triggers a significant elongation of the NN double bond, caused by an increase of its πg* antibonding character. This results in a reduction of the NN torsional barrier and thus in accelerated thermal Z → E isomerization. Combined with light-controlled E → Z isomerization, this enables controllable fractional tuning of the two configurational isomers
Y Yonezawa - One of the best experts on this subject based on the ideXlab platform.
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photoelectric response of a black lipid membrane containing an amphiphilic Azobenzene Derivative
Nature, 1991Co-Authors: Hironobu Fujiwara, Y YonezawaAbstract:LIPID membranes containing dye molecules that respond to light, for example by photoisomerization, may provide the basis for artificial visual systems for use in optoelectronic devices and optical transducers. Here we describe such a membrane/dye system that generates an electrical signal in response to irradiation within a specific range of wavelengths. We incorporated an amphiphilic Azobenzene Derivative into the planar black lipid membrane formed from egg lecithin. When a d.c. voltage is applied across the modified membrane, transient current pulses are induced by alternate irradiation with ultraviolet and visible light. We interpret this photoelectric response as the result of changes in the membrane capacitance caused by cis–trans photoisomerization of the Azobenzene Derivative.
