Fine‐tuning of the molecular structure of organic bistable compounds to improve their photochromic performance or to introduce additional functions remains an important issue in the development of photoresponsive materials. Diarylethenes bearing heterocyclic moieties belong to the most intensively studied class of organic photochromes due to their excellent photochemical properties. A huge number of diarylethenes have been synthesized so far. Analysis of the literature data shows that there are very worthy examples of diarylethenes developed by the Irie and Feringa groups, which can be the common starting material for a number of diarylethenes functionalized in hetaryl moieties. We refer to these structures as photochromic diarylethene precursors. These diarylethenes have proved to be very useful in the construction of functional molecules with desired properties. On the other hand, in our groups, we have elaborated on diarylethene precursors with modifiable ethene bridges. In this review, we have collected examples of such structures and their chemical modifications, leading to the improvement or fine‐tuning of photochromic switching. 相似文献
In recent years, organic field-effect transistors (OFETs) with high performance and novel multifunctionalities have attracted considerable attention. Meanwhile, featured with reversible photoisomerization and the corresponding variation in color, chemical/physical properties, photochromic molecules have been applied in sensors, photo-switches and memories. Incorporation of photochromic molecules to blend in the device functional layers or to modify the interfaces of OFETs is common way to build photo-transistors. In this review, we focus on the recent advantages on the study of photoresponsive transistors involving one of three typical photochromic compounds spiropyran, diarylethene and azobenzene. Three main strategies are demonstrated in detail. Firstly, photochromic molecules are doped in active layers or combined with semiconductor structure thus forming photoreversible active layers. Secondly, the modification of dielectric layer/active layer interface is mainly carried out by bilayer dielectric. Thirdly, the photo-isomerization of self-assembled monolayer (SAM) on the electrode/active layer interface can reversibly modulate the work functions and charge injection barrier, result in bifunctional OFETs. All in all, the combination of photochromic molecules and OFETs is an efficient way for the fabrication of organic photoelectric devices. Photoresponsive transistors consisted of photochromic molecules are potential candidate for real applications in the future. 相似文献
The review describes the photochromic and fluorescent characteristics of various diarylethene (DAET) derivatives, and presents recent research into their applications. This comprises a discussion of the optical characteristics of some DAET-based molecules exhibiting red, green, or blue (RGB) colors or fluorescence. Molecular calculations of the optical properties of DAET interpret intriguing experimental observations and predict photochemical or photophysical properties. In particular, stabilization of HOMO in the BTFOn (n = 1, 2, 3, 4) increases the energy difference between the HOMO and the LUMO, which leads to the blue-shift of absorption and emission bands as the number of oxygen attached to sulfur (n) increases. Various devices and application studies have been designed as photon-mode systems based on photochemical control of the fluorescence energy. The photochromic DAET materials have shown promise as optical data storage, switching devices, and biological applications such as the development of biomaterial sensors, analysis of biological dynamics, and live cell imaging. 相似文献
Stimuli‐responsive photoluminescent materials have attracted considerable attention owing to their potential applications in security protection because the information recorded directly in materials with static luminescent outputs are usually visible under either ambient or UV light. Herein, we realize reversible information anticounterfeiting by loading a photoswitchable diarylethene derivative into a lanthanide metal–organic framework (MOF). Light triggers the open‐ and closed‐form isomerization of the diarylethene unit, which respectively regulates the inactivation and activation of the photochromic FRET process between the diarylethene acceptor and lanthanide donor, resulting in reversible luminescence on–off switching of the lanthanide emitting center in the MOF host. This photoresponsive host–guest system allows for reversible multiple information pattern visible/invisible transformation by simply alternating the exposure to UV and visible light. 相似文献
Five diarylethene photochromic derivatives, the structures of which incorporate a central benzothiophene unit, a left‐hand thiazole group, and a right‐hand benzothiophene group, have been prepared. The compound with a thiazole unit with no substituent on the reaction‐center carbon atom reveals an unprecedented transformation upon light irradiation. When the 4‐position of thiazole is protected by a methyl group, the compounds show high photosensitivity and photochromic properties. In this case, light irradiation affords new compounds with [5]helicene structures featuring the highest redshifted absorption maxima reported to date. 相似文献
Four-coordinate organoboron compounds with a π-conjugated chelate backbone have emerged recently as highly attractive materials for a number of applications including use as emitters and electron-transport materials for organic light-emitting diodes (OLEDs) or organic field transistors, photoresponsive materials, and sensory and imaging materials. Many applications of this class of boron compounds stem from the electronic properties of the π-conjugated chelate backbone. Charge-transfer transitions from an aromatic substituent attached to the boron center of the π-conjugated chelate backbone and steric congestion have also been found to play important roles in the luminescent and photochromic properties of the four-coordinate boron compounds. This article provides an update-to-date account on the application aspects of this important class of compounds in materials science with the emphasis on OLED applications and photochromic switching. 相似文献
The diarylethene derivative 1,2‐bis‐(5′‐dimesitylboryl‐2′‐methylthieny‐3′‐yl)‐cyclopentene ( 1 ) containing dimesitylboryl groups is an interesting photochromic material. The dimesitylboryl groups can bind to F?, which tunes the optical and electronic properties of the diarylethene compound. Hence, the diarylethene derivative 1 containing dimesitylboryl groups is sensitive to both light and F?, and its photochromic properties can be tuned by a fluoride ion. Herein, we studied the substituent effect of dimesitylboron groups on the optical properties of both the closed‐ring and open‐ring isomers of the diarylethene molecule by DFT/TDDFT calculations and found that these methods are reliable for the determination of the lowest singlet excitation energies of diarylethene compounds. The introduction of dimesitylboron groups to the diarylethene compound can elongate its conjugation length and change the excited‐state properties from π→π* transition to a charge‐transfer state. This explains the modulation of photochromic properties through the introduction of dimesitylboron groups. Furthermore, the photochromic properties can be tuned through the binding of F? to a boron center and the excited state of the diarylethene compound is changed from a charge‐transfer state to a π→π* transition. Hence, a subtle control of the photochromic spectroscopic properties was realized. In addition, the changes of electronic characteristics by the isomerization reaction of diarylethene compounds were also investigated with theoretical calculations. For the model compound 2 without dimesitylboryl groups, the closed‐ring isomer has better hole‐ and electron‐injection abilities, as well as higher charge‐transport rates, than the open‐ring isomer. The introduction of dimesitylboron groups to diarylethene can dramatically improve the charge‐injection and ‐transport abilities. The closed isomer of compound 1 ( 1 C ) has the best hole‐ and electron‐injection abilities, whereas the charge‐transport rates of the open isomer of compound 1 ( 1 O ) are higher than those of 1 C . Importantly, 1 O is an electron‐accepting and ‐transport material. These results show that the diarylethene compound containing dimesitylboryl groups has promising potential to be applied in optoelectronic devices and thus is worth to be further investigated. 相似文献
Photochromic behavior of diarylethene derivatives with (4-pyridyl)ethynyl group directly attached to the 6-pi hexatriene moieties of the diarylethenes was investigated. Upon quaternarization of the pyridine moieties, the photoreactivity was strongly suppressed. On the other hand, diarylethene derivatives with nonconjugated (4-pyridyl)ethyl group exhibited the photochromic reactivity, regardless of whether pyridyl rings are quaternarized or not. In the case of the (4-pyridyl)ethynyl-substituted compounds, the photochromic reactivity was suppressed by the addition of trifluoroacetic acid and was restored by diethylamine. 相似文献
Abstract Photochromic polymeric materials have been commercialized in ophthalmic lenses, however, there are many other potential uses for this technology. The photochromic transitions are extremely sensitive to environmental conditions, thus offering the potential for modifying the kinetics to suit different applications. There are a significant number of photochromic molecular families, with different characteristics. The spiro-compounds, both spirooxazines and spiropyrans, have received the most attention as they have good coloration properties and spirooxazines also display good fatigue resistance. Consequently this review focuses on the inclusion of these compounds into polymer matrices. In addition we discuss decoloration and coloration behaviors, solvatochromism, mechanism of fatigue, and unusual synthetic approaches. 相似文献
A photochromic diarylethene with phenolic Schiff base 1a can be easily transformed to photochromic diarylethene with benzoxazole 3a in the conditions of base and phototrigger. Both of their photochromic properties are investigated. They show that the conversions of ring-open form to ring-closed form at photostationary equilibrium are ca. 20% and 10% for 3a and 1a, respectively, and the backconversions are in nearly quantitative yield for both compounds. They also show that the response time for photostationary equilibrium is ca. 0.5 and 5 min for 3a and 1a, respectively, in the solution. In addition, a general preparation of 2-arylbenzoxazole from phenolic Schiff base in the conditions of base and phototrigger is demonstrated by employing phenolic Schiff bases with different substituted groups as template, and other conditions (solvents, in the presence and absence of oxygen) for preparation of benzoxazole from phenolic Schiff base are explored as well. 相似文献
A diarylethene photoswitch was covalently connected to two small triplet sensitizer moieties in a conjugated and nonconjugated fashion and the photochromic performance of the resulting compounds was investigated. In comparison with the parent diarylethene (without sensitizers) and one featuring saturated linkages, the conjugated photoswitch offers superior fatigue resistance upon visible‐light excitation due to effective triplet energy transfer from the biacetyl termini to the diarylethene core. Our design makes it possible to switch diarylethenes with visible light in both directions in a highly efficient and robust fashion based on extending π‐conjugation and by‐product‐free ring‐closure via the triplet manifold. 相似文献
Summary: The phase behavior and optical properties of a cholesteric ternary copolymer, containing nematogenic phenylbenzoate, cholesteric, and photochromic diarylethene side groups, and its mixture with 2 wt.‐% fluorescent dopant were studied. The investigation of the kinetics of a photochemical opening‐cycle process of the photochromic groups in the cholesteric mixture proved the energy transfer from the fluorescent dopant to the photochromic diarylethene groups. It was shown that the fluorescence intensity of the fluorescent dopant could be controlled by the portion of the “closed” form of the diarylethene groups. During the photocyclization of the photochromic groups a “degeneration” of the selective light reflection of the cholesteric matrix is observed.
Fluorescence‐resonance energy transfer makes possible the process of photosensitization of the back ring‐opening photoreaction of the photochromic diarylethene groups in the cholesteric polymer matrix. 相似文献
Four new diarylethene derivatives based on thiophene or thiazole moieties were designed and synthesized, and the structures of compounds 4a and 5a were determined by single‐X‐ray diffraction analysis. All of these compounds showed reversible photochromic reactions and notable fluorescence photo‐switches in solution. Furthermore, diarylethenes 4a and 5a also showed good photochromism in single crystal phase. The electron‐donating and electron‐withdrawing substituents play the same role in the photochromic process: red‐shifted absorption and fluorescence ( 1a and 2a compared with 3a ). The fluorescent modulation efficiencies of asymmetrical diarylethenes 4 and 5 were significantly enhanced compared with the similar dithienylethenes, and the fatigue resistance of 5 was much better than 4 , which showed that the diarylethene bearing electron‐withdrawing group could improve its fatigue resistance. 相似文献
A new photochromic diarylethene (1a) has been prepared. Both its photochromic behavior and nonlinear optical properties are
investigated. 1a shows excellent ring-opening (λmax = 386 nm) and ring-closing (λmax = 652 nm) photoisomerization with UV-Vis light irradiation. With 800 nm femtosecond pulsed laser irradiation, 1a shows two-photon-induced
photoisomerization, and a two-photon absorption cross-section (σ = 423×1050 cm4·s per photon) is obtained by using two-photon induced fluorescence method. The applications of two-photon absorption of 1a
to holographic recording has been also investigated. A two-photon induced micro-pattern is recorded on the diarylethene 1a-PMMA
film with an femtosecond laser of 800 nm, 100 fs, 1 kHz, 50 mW. 相似文献