- Synthesis and characterization of new liquid crystals containing a non-activated indolinobenzospiropyranyl group. Part 4*[1]
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A series of new liquid crystalline compounds, 1′,3′,3′- Trimethylspiro[2H-1-benzopyran-2,2′-indolin/-6-yl 4-(4′- alkoxyphenylazo)benzoate, SP-APAB 1a ~ 1f, has been synthesized. Their liquid crystallines were subjected to thermal analysis on a differential scanning calorimeter (DSC), to texture of phases on a polarizing microscope and to phase transition on an X-ray diffraction mid electro-optical measurement. Most of compounds examined exhibit monotropic nematic and SmA liquid crystal phases on cooling from isotropic liquid. Suprisingly, SP-APAB 1c is shown to exhibit monotropic SmC phase in addition. X-ray diffraction study of the layer spacing confirmed that there was a layer spacing in the range of two theta from 2.25 to 2.45 A on the temperature near the phase transition from, SmA to SmC.
- Keum,Shin,Lee,Shin
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p. 119/[1161]-126/[1168]
(2004)
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- Improving the synthesis of spiropyran derivatives using microwave irradiation method
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A solvent free synthesis of spiropyran derivatives has been developed from the condensation of indoline and salicylaldehyde using a microwave irradiation method. This method starts from readily available starting materials and provides biologically interesting products. The microwave irradiation method was remarkably successful and gave spiropyran derivatives in higher yield (72-99%) with a much shorter reaction time (10-15 min) compared to the conventional heating method. The chemical structures of the compounds prepared were characterized through IR, 1H NMR and 13C NMR spectral data.
- Rohadi, Atisya,Hasbullah, Siti Aishah,Lazim, Azwan Mat,Nordin, Rumaisa
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p. 1017 - 1024
(2014/04/17)
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- Photoswitchable hydrogel surface topographies by polymerisation-induced diffusion
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Herein, we describe the preparation of patterned photoresponsive hydrogels by using a facile method. This polymer-network hydrogel coating consists of N-isopropylacrylamide (NIPAAM), cross-linking agent tripropylene glycol diacrylate (TPGDA), and a new photochromic spiropyran monoacrylate. In a pre-study, a linear NIPAAM copolymer (without TPGDA) that contained the spiropyran dye was synthesised, which showed relatively fast photoswitching behaviour. Subsequently, the photopolymerisation of a similar monomer mixture that included TPGDA afforded freestanding hydrogel polymer networks. The light-induced isomerisation of protonated merocyanine into neutral spiropyran under slightly acidic conditions resulted in macroscopic changes in the hydrophilicity of the entire polymer film, that is, shrinkage of the hydrogel. The degree of shrinkage could be controlled by changing the chemical composition of the acrylate mixture. After these pre-studies, a hydrogel film with spatially modulated cross-link density was fabricated through polymerisation-induced diffusion, by using a patterned photomask. The resulting smooth patterned hydrogel coating swelled in slightly acidic media and the swelling was higher in the regions with lower cross-linking densities, thus yielding a corrugated surface. Upon exposure to visible light, the surface topography flattened again, thus showing that a hydrogel coating could be created, the topography of which could be controlled by light irradiation.
- Stumpel, Jelle E.,Liu, Danqing,Broer, Dirk J.,Schenning, Albertus P. H. J.
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supporting information
p. 10922 - 10927
(2013/09/02)
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- Self-assembly of graphene oxide with a silyl-appended spiropyran dye for rapid and sensitive colorimetric detection of fluoride ions
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Fluoride ion (F-), the smallest anion, exhibits considerable significance in a wide range of environmental and biochemical processes. To address the two fundamental and unsolved issues of current F- sensors based on the specific chemical reaction (i.e., the long response time and low sensitivity) and as a part of our ongoing interest in the spiropyran sensor design, we reported here a new F- sensing approach that, via assembly of a F--specific silyl-appended spiropyran dye with graphene oxide (GO), allows rapid and sensitive detection of F- in aqueous solution. 6-(tert-Butyldimethylsilyloxy)-1′,3′,3′-trimethylspiro [chromene- 2,2′-indoline] (SPS), a spiropyran-based silylated dye with a unique reaction activity for F-, was designed and synthesized. The nucleophilic substitution reaction between SPS and F- triggers cleavage of the Si-O bond to promote the closed spiropyran to convert to its opened merocyanine form, leading to the color changing from colorless to orange-yellow with good selectivity over other anions. With the aid of GO, the response time of SPS for F- was shortened from 180 to 30 min, and the detection limit was lowered more than 1 order of magnitude compared to the free SPS. Furthermore, due to the protective effect of nanomaterials, the SPS/GO nanocomposite can function in a complex biological environment. The SPS/GO nanocomposite was characterized by XPS and AFM, etc., and the mechanism for sensing F- was studied by 1H NMR and ESI-MS. Finally, this SPS/GO nanocomposite was successfully applied to monitoring F- in the serum.
- Li, Yinhui,Duan, Yu,Zheng, Jing,Li, Jishan,Zhao, Wenjie,Yang, Sheng,Yang, Ronghua
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p. 11456 - 11463
(2014/01/06)
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- CERTAIN CHEMICAL ENTITIES, COMPOSITIONS, AND METHODS FOR MODULATING TRPV1
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Provided are chemical entities chosen from compounds of Formula (I) and pharmaceutically or cosmetically acceptable salts, solvates, chelates, non-covalent complexes, prodrugs, and mixtures thereof. The chemical entities modulate TRPV1 and are useful in the treatment of at least one disease or disorder modulated by TRPV1 activity.
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Page/Page column 41
(2008/06/13)
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- Spiropyran-based liquid crystals: The formation of columnar phases via acid-induced spiro-merocyanine isomerisation
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Hexagonal columnar liquid-crystalline phases are induced for a new fan-shaped spiropyran compound as the result of an acidichromism effect of spiro-merocyanine isomerisation through protonation upon incorporation of 4-methylbenzenesulfonic acid. The Royal Society of Chemistry.
- Tan, Boon-Hooi,Yoshio, Masafumi,Ichikawa, Takahiro,Mukai, Tomohiro,Ohno, Hiroyuki,Kato, Takashi
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p. 4703 - 4705
(2007/10/03)
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- Fischer's base as a protecting group: Protection and deprotection of 2- hydroxybenzaldehydes
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The hydroxyl and aldehyde groups of 2-hydroxybenzaldehydes were protected by the reaction with Fischer's base and deprotected by the ozonolysis in methanol at -78°C to give the corresponding 2- hydroxybenzaldehydes in good to high yields. (C) 2000 Elsevier Science Ltd.
- Cho, Young Jin,Lee, Seung Hwan,Bae, Jong Woo,Pyun, Hyung-Jung,Yoon, Cheol Min
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p. 3915 - 3917
(2007/10/03)
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- Synthesis of photochromic monomers with silyloxy substituents
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The preparation of photochromic spirobenzopyrans with silyloxy groups is described.
- Hosangadi, Bhaskar D.,Thakur, Sharmila K.
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p. 1137 - 1139
(2007/10/03)
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