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1.
We report a new expanded molecular logic system based upon combinations of spiropyrans, spirooxazines and chromenes, whereby the photochromism of some molecules can be selectively preserved while reversibly deactivating the photochromism of others. The non-photochromic molecules can be reversibly activated by CO2 gas. It was found that the photochromic effect of spiropyrans, in general, and one spirooxazine (with a hydroxyl group on the naphtho-ring) could be reversibly deactivated by DBU, while a chromene and an unsubstituted spirooxazine remained photochromic in the system under the same conditions. The presence of protic solvent was necessary for the deactivation of some of these photochromic molecules and hence it was used as an additional sensitizer in the system. This afforded the expansion of stimuli for molecular logic operations and allowed combinations of the benign stimuli of UV, visible light, CO2, and CO2 depleted with protic and aprotic solvents. This effect provided the mechanism for molecular logic systems that do not suffer from the usual problems of dilution effects and hence become truly reversible. This is highly significant when designing molecular switches to perform logic operations. 相似文献
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A. Miyata T. Matsushima H. Ohki Y. Unuma Y. Higashigaki 《Advanced functional materials》1995,5(1):37-43
Spiropyran SP1822 J-aggregate LB films show a non-linear photochromic response with a threshold against the incident light intensity of a CW dye laser. Using two laser beams operating below the threshold level intensity, the logic ‘AND’ function was found to be optically stored as an overlapping region of two incident patterns. We proposed the adoption of an LB film of spiropyran J-aggregates to store the memory matrix Tijkl as an overlapping region of learning input pattern Vij and multi-image input pattern Vkl in order to construct an optical neural network system based on Hopfield model. 相似文献
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Akihiro YamanoHiromitsu Kozuka 《Thin solid films》2011,519(6):1772-1779
Polymethylmethacrylate (PMMA)-perhydropolysilazane (PHPS) hybrid thin films doped with spiropyran were prepared by spin-coating, which were then converted into 0.26-1.7 μm thick, spiropyran-doped PMMA-silica hybrid films by exposure treatment over aqueous ammonia. The spiropyran/(spiropyran + PHPS + PMMA) mass ratio was fixed at a high value of 0.2 so that the films exhibit visual photochromic changes in color, while the PMMA/(PMMA + PHPS) mass ratio, r, was varied. The spiropyran molecules in the as-prepared films were in merocyanine (MC) and spiro (SP) forms, with and without an optical absorption at 500 nm, at low (r ≤ 0.2) and high (r ≥ 0.4) PMMA contents, respectively. When PMMA content r was increased from 0 to 0.2, the degree of the MC-to-SP conversion on vis light illumination was enhanced, while at higher r's the spiropyran molecules underwent photodegradation. When the silica film (r = 0) was soaked in xylene under vis light, the spiropyran molecules were almost totally leached out, while not on soaking in the dark. On the other hand, no leaching occurred for the film of r = 0.2 either in the presence or absence of vis light. These suggest that the introduction of PMMA is effective in improving the chemical durability of the films, while the silica film (r = 0) is an interesting material with a photoresponsive controlled-release ability. The pencil hardness of the films decreased with increasing PMMA content, but remained over 9H at r ≤ 0.4. 相似文献
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《中国稀土学报(英文版)》2020,38(4):445-450
A spiropyran-based probe was developed.It serves as a fluorescence turn-on probe for selective detection of Ce~(3+) in both ethanol and aqueous(water/ethanol,1:9 or 9:1,v/v) media.Ce~(3+) can induce photochromism of the probe though the probe exhibits negligible photochromic property by itself.The probe is sensitive to Ce~(3+) and the detection limit reaches 1.7 μmol/L.It exhibits a high selectivity for Ce~(3+)ion over other common metal cations including Li~+,Na~+,Ag~+,Sr~(2+),Ni~(2+),Co~(2+),Hg~(2+),Zn~(2+),Cr~(3+),Al~(3+),Fe~(3+) and Bi~(3+) and lanthanide ions Nd~(3+),Yb~(3+) and La~(3+).The probe may be used for quantitative determination of the concentration of Ce~(3+) ion in a range of 1-10 μmol/L and for application to environmental water samples.Sensing mechanism of the probe towards Ce~(3+) ion is proposed. 相似文献
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Kenji Kinashi Hiroyuki Kita Masahiro Misaki Yasuko Koshiba Kenji Ishida Yasukiyo Ueda Mari Ishihara 《Thin solid films》2009,518(2):651-15153
A cationic spiropyran iodide derivative (SPI) was synthesized as a photoresponsive compound, and SPI/montmorillonite clay hybrid films were prepared using ion- and guest-exchange intercalation methods. When the ion-exchange method was applied to clay with a low cation-exchange capacity (CEC), intercalation of SPI into clay interlayers did not occur. Using the clay with a high CEC, SPI was intercalated into clay interlayer and the interlayer distances were elongated. Upon UV and visible light irradiation, SPI in hybrid film photoisomerized reversibly and the interlayer distance also changed reversibly. On the other hand, intercalation by the guest-exchange method using cethyltrimethylammoniumbromide (CTAB) as a pre-exchanging reagent was independent on the CEC. After the addition of SPI, the CTAB in the clay interlayers was exchanged for SPI, but a partial CTAB remained in the interlayer. SPI in the hybrid films prepared by the guest-exchange method photoisomerized reversibly without any change in interplanar distance due to the coexisted CTAB. 相似文献
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Kenji Kinashi 《Thin solid films》2008,516(9):2532-2536
Three types of spiropyran derivatives introduced octadecyl group (SP18), hydroxyl group (SPOH) and carboxyl group (SPCOOH) were synthesized and were dispersed into various matrices such as chloroform solvent, polymethylmetacrylate (PMMA)/acetone solution and poly(perhydrosilazane) (PSz)/m-xylene solution. Thermal stability of photomerocyanine isomer (PMC-form) in spiropyran derivatives dispersed in silica composite film was studied. Intensity at λmax of PMC-form in silica composite film keeps at initial values in long time except for SP18. PMC-form of SPOH and SPCOOH forms intermolecular hydrogen bonding between hydroxyl or carboxyl group and oxygen atom in silica matrix. Therefore, PMC-form of SPOH and SPCOOH in silica composite film is stabilized dramatically. 相似文献
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Min Ju Cho Go Woon Kim Woong Gi Jun Sang Kyu Lee Jung-Il Jin Dong Hoon Choi 《Thin solid films》2006,500(1-2):52-60
First and second generation dendrimers that exhibit unique photochromic behavior were synthesized through multi-step reactions. Their photochromic behavior under illumination of monochromatic ultraviolet light (λ = 365 nm) was investigated. The colorless dendritic dye solution and its film exhibit typical ring opening and E/Z geometrical transformation from spiropyran to merocyanine. The stability of photochromism in the two dendrimers was much better than that observed in the dye-attached polymer or dye-doped polymer system. Particularly, blend material system of photochromic dendrimer and photocrosslinkable dendrimer showed much better stability of the photochromism. 相似文献
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New methacrylic copolymers, bearing in the side chain spiropyran moieties and/or the optically-active (S)-3-hydroxy pyrrolidinyl group linked through the nitrogen atom to an azopyridine chromophore, along with an opportune molar content of methyl methacrylate co-units, have been prepared by radical polymerization of the corresponding monomers.The resulting macromolecules have been fully characterized with particular attention to the study of their thermal stability, optical activity, chiroptical and photoinduced properties.In the presence of acid, it is possible to modulate the protonation of the azopyridine groups by photo-isomerization (with UV and/or Vis light) of the spiropyran component. The resulting signal communication between these macromolecular switches can be monitored by UV-VIS as well as CD spectroscopy and is completely reversible and reproducible.The results are discussed in terms of copolymer composition and different cooperative behaviour, which lead to a variation of interactions between spiropyran and azoaromatic chromophores and reveal that the best proton transfer is actually obtained in the random terpolymer with lower amounts of co-units of spiropyran and azopyridine chromophores in the side chain, which displays improved sensitivity to proton-transfer process and, in addition, exhibits good stability to repeated cycles of irradiation with UV and Vis light. 相似文献