- Photochromism and solvatochromism of push-pull or pull-push spiroindolinenaphthoxazines
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The photochromic and solvatochromic behaviour of 17 variously substituted spiroindoline naphthoxazines has been investigated in cyclohexane, toluene, acetonitrile and methanol in fluid solution. Specific parameters such as the wavelengths and the molar ab
- Metelitsa,Lokshin,Micheau,Samat,Guglielmetti,Minkin
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- Coupling between Photochromism and Second-Harmonic Generation in Spiropyran- and Spirooxazine-Doped Polymer Films
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The photochemical ring opening of spiropyrans in polymethylmethacrylate (PMMA) host films in the presence of a high-voltage electric field (2-5 MV/cm) leads to a photo-orientation of photomerocyanines.Since photomerocyanines have rather high first-order hyperpolarizabilities, this photo-orientation leads to second-harmonic generation (SHG).The second-order susceptibility d33 of PMMA films doped with 6-nitro-1',3',3'-trimethylspiro (25percent w/w) has been measured at 10 pm/V.If a PMMA film doped with spiropyran and preoriented by corona poling at 90 deg C is irradiated in the UV, an SHG signal of photomerocyanine is also observed as a result of a memory effect of the orientation of spiropyran molecules.The photoswitching of this nonlinear optical property can be inverted by visible light irradiation.Only partially reversible switching is observed because of a gradual light-induced disorientation of photomerocyanine dipoles.Photochemical quantum yields of the spiropyranphotomerocyanine reaction have also been determined in PMMA for one system.Dipole moments and hyperpolarizabilities of closed and open forms have been calculated by semiempirical and finite field methods for an analogous system.
- Atassi, Yomen,Delaire, Jacques A.,Nakatani, Keitaro
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- One-pot synthesis of photochromic 6′-amino-substituted spirooxazines from 1-nitroso-2-naphthol zinc chelate and indoline base
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A series of spirooxazine derivatives containing nitrogen heterocycles were synthesized through the condensation of 2-methylene-1,3,3-trimethylindoline derivatives with the zinc salt of 1-nitroso-2-naphthol using ethanol as solvent. The method is simple, starts from readily accessible and inexpensive reagents, and leads to the synthesis of 6′-substituted spirooxazines in moderate to good yields. We simplified the workup and found that, for some target compounds, recrystallization can effectively improve efficiency of the separation and purification. Georg Thieme Verlag Stuttgart.
- Pang, Mei-Li,Zhang, Hui-Juan,Liu, Pei-Pei,Zou, Zhi-Hong,Han, Jie,Meng, Ji-Ben
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experimental part
p. 3418 - 3422
(2010/11/20)
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- Synthesis, characterization and photochromic studies in film of heterocycle-containing spirooxazines
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A series of novel heterocycle-containing spirooxazines have been designed and synthesized, and their photochromic properties were investigated under flash photolysis and continuous irradiation in particular regard to the fatigue resistance, the lifetime of the colored merocyanine form in various solutions and polymers. Especially, the characteristics of two UV-sensitive spirooxazines dispersed polymethylmethacrylate thin-films were extensively studied. Detailed studies showed that general significant shifts in the λmax of the absorption spectra of the open forms, interesting fatigue resistances and emission fluorescene properties were observed.
- Tan, Ting-Feng,Chen, Pei-Li,Huang, Hua-Ming,Meng, Ji-Ben
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p. 8192 - 8198
(2007/10/03)
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- One-pot synthesis of 6′-amino-substituted spirooxazines
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A one-pot synthesis of 6′-amino-substituted spiroindolinonaphth[2,1- b][1,4]oxazines is developed through the condensation of 2-methylene-1,3,3- trimethylindoline derivatives and 1-amino-2-naphthol in the presence of different secondary amines and oxidizing agents using methanol or toluene as the solvent. The main advantage of the method is its simplicity, and starting from readily accessible reagents, it allows the preparation of amino derivatives of spironaphthoxazine with good yields under mild reaction conditions. Georg Thieme Verlag Stuttgart.
- Koshkin,Lokshin,Samat,Gromov,Fedorova
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p. 1876 - 1880
(2007/10/03)
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- Red colouring photochromic 6′-substituted spiroindolinonaphth[2,1-b][1,4]oxazines
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Electron donating/withdrawing substituents and electronegative centres have been successfully employed in substantially widening the range of photo-generated colours available in the spiroindolinonaphthoxazine class of photochromic materials.
- Rickwood,Marsden,Ormsby,Staunton,Wood,Hepworth,Gabbutt
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- Sensibilisation du photochromisme de spirooxazines par transfert d'energie triplet-triplet
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The present publication describes sensitized photocoloration by triplet-triplet energy transfer of some photochromic spirooxazines.The dominant reaction leading to the colored dye product B in the direct photolysis of the spirooxazine (SPO) in toluene involves the singlet excited state but the results obtained in this work show that both triplet and singlet states are involved in the color-forming reaction.We employed sensitizers of decreasing triplet energy in an attempt to locate the triplet level in the SPO.From the triplet energies of the sensitizers of the SPO color formation it can be concluded that the energy of the spirooxazine triplet state is about 212 kJ.mol-1.The camphorquinone (CQ) sensitizes the formation of B.This compound is particularly suitable for investigation of sensitized photocoloration of spirooxazines since it absorbs in a region of the spectrum where SPO does not absorb (λmax = 471 nm).Then, it is possible to extend the photochromic properties of the SPO to the visible region (λ 500 nm) for industrial applications.The absorption spectra of the colored form were determined for the direct and sensitized photolysis in toluene solutions.
- Eloy, D.,Escaffre, P.,Gautron, R.,Jardon, P.
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p. 897 - 914
(2007/10/02)
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