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Holography with Photochromic Diarylethenes
摘要： Photochromic materials are attractive for the development of holograms for different reasons: they show a modulation of the complex refractive index, meaning they are suitable for both amplitude and phase holograms; they are self-developing materials, which do not require any chemical process after the light exposure to obtain the final hologram; the holograms are rewritable, making the system a convenient reconfigurable platform for these types of diffractive elements. In this paper, we will show the features of photochromic materials, in particular diarylethenes in terms of the modulation of a transparency and refractive index, which are mandatory for their use in holography. Moreover, we report on the strategies used to write binary and grayscale holograms and their achieved results. The outcomes are general, and they can be further applied to other classes of photochromic materials in order to optimize the system for achieving high efficiency and high fidelity holograms.
关键词： holography,refractive index,diarylethenes,photochromism,CGH
更新于2025-09-11 14:15:04
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External Reversal of Chirality Transfer in Photoswitches
摘要： The transfer of stereoinformation is at the heart of asymmetric reactions. By incorporating the natural monoterpene L-menthone into the backbone of a diarylethene, we could achieve efficient chirality transfer upon photocyclization resulting in the preferred formation of one major closed isomer in a diastereomeric ratio (dr) of 85 : 15. More significantly, we were able to completely reverse the diastereomeric outcome of the ring-closure, simply by altering the chemical environment or the irradiation conditions. As a result, we could selectively accumulate the less favored minor closed isomer, with remarkable dr values of > 99 : 1 and 74 : 26, respectively. Computations reveal that a stability inversion after photocyclization is the basis for the observed unprecedented control over diastereoselectivity.
关键词： diastereoselectivity,diarylethenes,chirality,photochromism,electrocyclization
更新于2025-09-10 09:29:36
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Remarkable responsive behaviors of iso-aminobenzopyranoxanthenes: protonation effect, photochromism and piezochromism
摘要： The iso-cis/trans-aminobenzopyranoxanthenes (iso-cis/trans-ABPXs), as one of popular leuco dyes, were investigated in solution or crystal phase. The introduction of benzo-pentacyclic-ester group in iso-cis/trans-ABPXs leads to remarkable multi-stimuli responsive behaviors, including protonation effect, photochromism and piezochromism with notable color changes. The iso-cis/trans-ABPXs show different in the responsive sensitivity and the iso-cis-ABPX is highly sensitive to environmental stimuli relative to the trans-form, which can be explained by their different C-H?O interaction and/or C-O bond length. Interestingly, as the ultraviolet light irradiation time increasing, the iso-cis/trans-ABPXs solution gradually becomes transparent and orange precipitates are achieved, which is identified as iso-ABPXs ±. Multi-stimuli responsive behaviors on the iso-cis/trans-ABPXs provide a comprehensive insight into the chromogenic mechanisms of this type of materials, suggesting that they may be potential candidate materials for sensors and indicators.
关键词： Protonation effect,Piezochromism,Photochromism,Spirolactone ring,Tautomerizm
更新于2025-09-10 09:29:36
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New photochromic indoline spiropyrans containing cationic substituent in the 2H-chromene moiety
摘要： New indoline spiropyrans containing conjugated cationic fragments and bulky substituents in the 2H-chromene moiety were synthesized by a simple one-pot method. The structures of the obtained compounds were confirmed by 1H and 13C NMR (including 2D methods) and IR spectroscopy, as well as by element analysis and HRMS. Molecular structure of 1,3,3-trimethyl-60-formyl-80-benzyl-spiro[indoline-2,20-2H-chromene] was refined by single crystal X-ray. A comparative analysis of the spectral and photochromic properties of salt spiropyrans and similar structures without a cationic fragment was carried out. It was found that the introduction of the cationic substituent at the 60-position of the 2H-chromene moiety leads to a significant increase in the photoinduced isomer's lifetime.
关键词： Indolines,Molecular switches,2H-chromenes,Photochromism,Single crystal X-ray analysis,Spiropyrans
更新于2025-09-09 09:28:46
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Ambipolar carrier transport in an optically controllable diarylethene thin film transistor
摘要： Ambipolar carrier transport is demonstrated in an optically controllable organic field-effect transistor, where a benzothienothiophene-substituted diarylethene (BTT-DAE) thin film is employed directly as the transistor channel. A closed-ring isomer, which is produced by ultraviolet (UV) light irradiation, allows the carrier injection of both holes and electrons from source-drain electrodes into the BTT-DAE layer. Moreover, alternate UV or visible (VIS) light irradiation induces marked switching in the drain currents caused by reversible photoisomerization between closed-ring (semiconductor) and open-ring (insulator) isomers. The light-driven on/off ratio, which is defined by the ratio of the drain currents in the sample after UV or VIS light irradiation, reaches 240 for hole transport. The value is comparable to the gate-voltage-induced on/off ratio of 160. Our findings, therefore, have a potential to lead to the construction of new optoelectronic devices such as photoreconfigurable logic circuits and light emitting transistors.
关键词： Ambipolar operation,Optical switching,Organic field-effect transistor,Diarylethene,Photochromism
更新于2025-09-09 09:28:46
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A facile method for regulating the charge transfer route of WO3/CdS in high-efficiency hydrogen production
摘要： In order to intrinsically boost the photocatalytic performance of WO3/CdS, the charge transfer route can be modulated from conventional type-Ⅱ to Z-scheme by incorporating of hydrogen ions into WO3/CdS to form H0.53WO3/CdS. This work indicates that only when charge transfer of WO3/CdS is type-Ⅱ, can H0.53WO3/CdS composite be formed in-situ. Subsequently, the Z-scheme photocatalytic mechanism plays its prominent roles in gradually improving photocatalytic H2 evolution performance. H0.53WO3/CdS has high photocatalytic activity for hydrogen production, which is much higher than that of WO3/CdS. This work will provides an in-depth understanding of charge separation and transfer processes and steer charge flow in a Z-scheme manner for efficient solar-to-chemical energy applications.
关键词： type-Ⅱ,Z-scheme,H0.53WO3/CdS,charge transfer route,photochromism
更新于2025-09-09 09:28:46
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External Reversal of Chirality Transfer in Photoswitches
摘要： The transfer of stereoinformation is at the heart of asymmetric reactions. By incorporating the natural monoterpene L-menthone into the backbone of a diarylethene, we could achieve efficient chirality transfer upon photocyclization resulting in the preferred formation of one major closed isomer in a diastereomeric ratio (dr) of 85 : 15. More significantly, we were able to completely reverse the diastereomeric outcome of the ring-closure, simply by altering the chemical environment or the irradiation conditions. As a result, we could selectively accumulate the less favored minor closed isomer, with remarkable dr values of > 99 : 1 and 74 : 26, respectively. Computations reveal that a stability inversion after photocyclization is the basis for the observed unprecedented control over diastereoselectivity.
关键词： diarylethenes,diastereoselectivity,electrocyclization,chirality,photochromism
更新于2025-09-09 09:28:46
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Hydrophilic Internal Pore and Hydrophobic Particle Surface of Organically Modified Mesoporous Silica Particle to Host Photochromic Molecules
摘要： The external surface of a mesoporous silica, MCM-41, was functionalized with phenyl group to obtain dual domain mesoporous silica particle (hydrophobic particle surface and hydrophilic mesopore) for photochrmoism of merocyanine/spiropyran. Merocyanine was adsorbed on MCM-41 and that functionalized with phenyl group by the photoinduced adsorption. The red hybrid of Ph-MCM-41 showed negative photochromism with a higher decolorization efficiency and a faster thermal colorization than the hybrid of MCM-41, suggesting the photogenerated spiropyran diffused into the hydrophobic surface.
关键词： Mesoporous silica,Surface modification,Negative photochromism
更新于2025-09-04 15:30:14
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Multichromophoric sugar for fluorescence photoswitching
摘要： A multichromophoric glucopyranoside 2 bearing three dicyanomethylenepyran (DCM) fluorophores and one diarylethene (DAE) photochrome has been prepared by Cu(I)-catalyzed alkyne–azide cycloaddition reaction. The fluorescence of 2 was switched off upon UV irradiation, in proportion with the open to closed form (OF to CF) conversion extent of the DAE moiety. A nearly 100% F?rster-type resonance energy transfer (FRET) from all three DCM moieties to a single DAE (in its CF) moiety was achieved. Upon visible irradiation, the initial fluorescence intensity was recovered. The observed photoswiching is reversible, with excellent photo resistance.
关键词： energy transfer,monosaccharide,photochromism,click chemistry,fluorophore
更新于2025-09-04 15:30:14