- Preparation of chiral luminescent liquid crystals and manipulation effect of phase structures on the circularly polarized luminescence property
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Realizing a larger luminescence asymmetry factor (glum) and a higher solid-state luminescence quantum yield are vital for promoting the application of circularly polarized luminescence (CPL) materials; however, they are challenging to achieve. This study utilizes the chirality amplification effect from chiral liquid crystals and the intense solid-state emission feature from aggregation-induced emission enhancement (AIEE) fluorophores to generate a high efficiency CPL-active chiral luminescent liquid crystal (NO2-CS-C6-Chol). During annealing, cholesteric phase, chiral smectic C (SmC?) phase and crystalline phase were observed successively. To suppress the strong thermo-activated nonradiative decay, we froze the assembly structure of the cholesteric phase and SmC? phase with liquid nitrogen. As a result, the cholesteric film (State C), SmC? film (State B) and crystalline film (State A) stable at room temperature were obtained. The study focuses on the photophysical properties in different phase state films, particularly the impact of phase structures on the properties of CPL. The results show that NO2-CS-C6-Chol presented a large glum value and excellent fluorescence efficiencies in State C and B, while no CPL signal was detected in State A. Based on the thermo-driven phase transition feature of NO2-CS-C6-Chol, CPL can switch from one state to the other two states at our will, indicating the significant manipulation effect of phase structures on the CPL properties. This work is conducive to deeply understand the generation and amplification mechanisms of chirality.
- Chen, Youde,Lu, Peng,Gui, Qin,Li, Zhiyan,Yuan, Yongjie,Zhang, Hailiang
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p. 1279 - 1286
(2021/02/16)
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- 1,8-Dioxapyrene-based electrofluorochromic supramolecular hyperbranched polymers
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A novel 1,8-dioxapyrene-based electrofluorochromic supramolecular polymer has been successfully constructed, through the coordination of terpyridine ligands with Eu3+ ions. The resulting polymer is capable of displaying multicolor tunable capac
- Qiu, Shuai,Gao, Zhao,Yan, Fei,Yuan, Hongxing,Wang, Jingxia,Tian, Wei
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supporting information
p. 383 - 386
(2020/01/11)
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- Stress-induced colouration and crosslinking of polymeric materials by mechanochemical formation of triphenylimidazolyl radicals
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Under mechanical stress, the hexaarylbiimidazole (HABI) motif can cleave to triphenylimidazolyl radicals when incorporated into a polymer matrix. The mechanically produced coloured radicals can initiate secondary radical reactions yielding polymer network
- Verstraeten,G?stl,Sijbesma
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supporting information
p. 8608 - 8611
(2016/07/14)
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- Liquid crystal aligning, liquid crystal alignment film, the liquid crystal display element and manufacturing method of the liquid crystal display element, and polymerizable compound
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A polymerisable compound having a terminal having an a-methylene-?-butyrolactone group and a terminal having a photopolymer or a photocrosslinking group; a polymer for forming a liquid crystal aligning agent capable of aligning liquid crystals; and a liqu
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Page/Page column 70; 71
(2016/10/08)
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- Monolayer to Interdigitated Partial Bilayer Smectic C Transition in Thiophene-Based Spacer Mesogens: X-ray Diffraction and 13C Nuclear Magnetic Resonance Studies
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Mesophase organization of molecules built with thiophene at the center and linked via flexible spacers to rigid side arm core units and terminal alkoxy chains has been investigated. Thirty homologues realized by varying the span of the spacers as well as the length of the terminal chains have been studied. In addition to the enantiotropic nematic phase observed for all the mesogens, the increase of the spacer as well as the terminal chain lengths resulted in the smectic C phase. The molecular organization in the smectic phase as investigated by temperature dependent X-ray diffraction measurements revealed an interesting behavior that depended on the length of the spacer vis-a-vis the length of the terminal chain. Thus, a tilted interdigitated partial bilayer organization was observed for molecules with a shorter spacer length, while a tilted monolayer arrangement was observed for those with a longer spacer length. High-resolution solid state 13C NMR studies carried out for representative mesogens indicated a U-shape for all the molecules, indicating that intermolecular interactions and molecular dynamics rather than molecular shape are responsible for the observed behavior. Models for the mesophase organization have been considered and the results understood in terms of segregation of incompatible parts of the mesogens combined with steric frustration leading to the observed lamellar order.
- Kesava Reddy,Varathan,Lobo, Nitin P.,Roy, Arun,Narasimhaswamy,Ramanathan
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p. 10831 - 10842
(2015/10/12)
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- Switchable intermolecular communication in a four-fold rotaxane
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Firmly tied: A four-fold rotaxane was prepared from a porphyrin unit with four alkylammonium chains and a phthalocyanine unit with four peripheral crown ethers. In a dinuclear Cu2+ complex of the four-fold rotaxane, the Cu2+-porphyri
- Yamada, Yasuyuki,Okamoto, Mitsuhiro,Furukawa, Ko,Kato, Tatsuhisa,Tanaka, Kentaro
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supporting information; experimental part
p. 709 - 713
(2012/02/15)
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- Red/near-infrared light-emitting organic-inorganic hybrids doped with covalently bound boron dipyrromethene (BODIPY) dyes via microwave-assisted one-pot process
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Red/near-infrared (NIR) light-emitting boron dipyrromethene (BODIPY) dyes bearing methacryloyl groups were synthesized, and these dyes were covalently bonded to poly(2-hydroxyethyl methacrylate) (PHEMA)silica hybrids. The preparation of their hybrids was performed by simultaneous solgel reaction of trimethoxy(methyl)silane and radical copolymerization of 2-hydroxyethyl methacrylate (HEMA) with the dyes under microwave irradiation or conventional heating. Strong red/NIR light-emitting hybrids without discoloration of the dyes were successfully obtained under microwave irradiation, whereas the dyes lost luminescent properties in the hybrids prepared under conventional heating. Photostability test of the hybrids showed that covalent attachment of the dyes led to significant improvement in the photostability in comparison with the solution state. Further, elution amount of the dyes from the hybrids in organic solvents decreased relative to that from physical dye-admixing hybrids due to the covalent bond between PHEMA and the dyes.
- Kajiwara, Yuichi,Nagai, Atsushi,Chujo, Yoshiki
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experimental part
p. 471 - 481
(2011/07/09)
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- Phase characterization and study of molecular order of a three-ring mesogen by 13C NMR in smectic C and nematic phases
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Molecules exhibiting a thermotropic liquid-crystalline property have acquired significant importance due to their sensitivity to external stimuli such as temperature, mechanical forces, and electric and magnetic fields. As a result, several novel mesogens have been synthesized by the introduction of various functional groups in the vicinity of the aromatic core as well as in the side chains and their properties have been studied. In the present study, we report three-ring mesogens with hydroxyl groups at one terminal. These mesogens were synthesized by a multistep route, and structural characterization was accomplished by spectral techniques. The mesophase properties were studied by hot-stage optical polarizing microscopy, differential scanning calorimetry, and small-angle X-ray scattering. An enantiotropic nematic phase was noticed for lower homologues, while an additional smectic C phase was found for higher homologues. Solid-state high-resolution natural abundance 13C NMR studies of a typical mesogen in the solid phase and in the mesophases have been carried out. The 13C NMR spectrum of the mesogen in the smectic C and nematic phases indicated spontaneous alignment of the molecule in the magnetic field. By utilizing the two-dimensional separated local field (SLF) NMR experiment known as SAMPI4, 13C-1H dipolar couplings have been obtained, which were utilized to determine the orientational order parameters of the mesogen. ? 2011 American Chemical Society.
- Kalaivani,Narasimhaswamy,Das, Bibhuti B.,Lobo, Nitin P.,Ramanathan
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scheme or table
p. 11554 - 11565
(2011/12/15)
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- BIFUNCTIONAL POLYMERIZABLE COMPOUND, POLYMERIZABLE LIQUID CRYSTAL COMPOSITION, AND ORIENTED FILM
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Disclosed is a bifunctional polymerizable compound represented by the formula [1]. Also disclosed is a polymerizable liquid crystal composition comprising at least one bifunctional polymerizable compound represented by the formula [1] and a polymerizable liquid crystal compound. The bifunctional polymerizable compound has a high polymerizability. When added to a polymerizable liquid crystal compound to prepare a polymerizable liquid crystal composition, the bifunctional polymerizable compound enables to remarkably improve the thermal stability of a polymer produced from the composition. The polymerizable liquid crystal composition containing the bifunctional polymerizable compound has a low crystallization temperature and shows a stable liquid-crystallinity under ordinary environment. wherein X1, X2 and X3 independently represent a single bond or a benzene ring; Y represents -O- or a single bond; M represents a lactone ring or an acrylate group; and n represents an integer of 4 to 10.
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Page/Page column 27
(2009/07/10)
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- Porphyrin derivatives their use in photodynamic therapy and medical devices containing them
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There is provided a compound of formula (I), wherein R1, R2, R3, R4, R5, R6, R7, R8, R9, X, Y1, Y2, Y3, Z, M, A-B and C-D have meanings given in the description, which are useful in the treatment of medical conditions for which a photodynamic compound is indicated. Compositions, apparatus and methods of treatment of a medical condition for which a photodynamic compound is indicated are also disclosed.
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- Design, synthesis and photophysical properties of C60-modified proteins
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Fullerene-porphyrin conjugates coordinated with Fe and Zn ions (1·Fe and 1·Zn) were designed and synthesized. Compounds 1·Fe and 1·Zn were reconstituted into apomyoglobin successfully to produce C60-modified myoglobins, 1·Fe-Mb and 1·Zn-Mb, res
- Murakami, Hiroto,Matsumoto, Rika,Okusa, Yuko,Sagara, Takamasa,Fujitsuka, Mamoru,Ito, Osamu,Nakashima, Naotoshi
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p. 2026 - 2033
(2007/10/03)
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- Synthesis, characterisation, and phase behaviour of some azines with potential optical nonlinearities of second order
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Some azines with potential nonlinear optical properties of the second order have been synthesised by condensation of the appropriate hydrazones and aldehydes. The compounds have been chemically functionalised to allow their use in the synthesis of polymers containing the azine groups as side chain pendants. The characterisation of the phase behaviour, performed by DSC, X-ray diffraction and polarising microscopy methods, shows that most of the compounds exhibit enantiotropic liquid crystalline properties. Some peculiar features concerning solid state polymorphism have also been investigated.
- Centore,Panunzi,Roviello,Sirigu,Villano
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p. 107 - 120
(2007/10/03)
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- Colourless Nonlinear Optical D-?-A Polymers with Sulphones as Electron Acceptors
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Novel colourless side-chain methacrylate copolymers exhibiting relatively narrow charge-transfer bands at 335 nm and second order optical nonlinearities up to d33 = 4.3 pm V-1 (at 1064 nm) have been synthesized and characterized.
- Nijhuis, S.,Rikken, G. L. J. A.,Havinga, E. E.,Hoeve, W. ten,Wynberg, H.,Meijer, E. W.
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p. 1093 - 1094
(2007/10/02)
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