Photochromic Diarylethene Derivative Research Articles

Tunable Multicolor Lanthanide Supramolecular Assemblies with White Light Emission Confined by Cucurbituril[7

Macrocyclic confinement-induced supramolecular luminescence materials have important application value in the fields of bio-sensing, cell imaging, and information anti-counterfeiting. Herein, a tunable multicolor lanthanide supramolecular assembly with white light emission is reported, which is constructed by co-assembly of cucurbit[7]uril (CB[7]) encapsulating naphthylimidazolium dicarboxylic acid (G1 )/Ln (Eu3+ /Tb3+ ) complex and carbon quantum dots (CD). Benefiting from the macrocyclic confinement effect of CB[7], the supramolecular assembly not only extends the fluorescence intensity of the lanthanide complex G1 /Tb3+ by 36 times, but also increases the quantum yield by 28 times and the fluorescence lifetime by 12 times. Furthermore, the CB[7]/G1 /Ln assembly can further co-assemble with CD and diarylethene derivatives (DAE) to realize the intelligently-regulated full-color spectrum including white light, which results from the competitive encapsulation of adamantylamine and CB[7], the change of pH, and photochromic DAE. The multi-level logic gate based on lanthanide supramolecular assembly is successfully applied in anti-counterfeiting system and information storage, providing an effective method for the research of new luminescent intelligent materials.

Photochromic Single-Component Organic Fulgide Ferroelectric with Photo-Triggered Polarization Response.

Organic photochromic compounds have been widely investigated for optical memory storage and switches. Very recently, we pioneeringly discovered optical control of ferroelectric polarization switching in organic photochromic salicylaldehyde Schiff base and diarylethene derivatives, differently from the traditional ferroelectrics. However, the study of such intriguing photo-triggered ferroelectrics is still in its infancy and relatively scarce. In this manuscript, we synthesized a pair of new organic single-component fulgide isomers, (E and Z)-3-(1-(4-(tert-butyl)phenyl)ethylidene)-4-(propan-2-ylidene)dihydrofuran-2,5-dione (1E and 1Z). They undergo prominent photochromism from yellow to red. Interestingly, only polar 1E has been proven to be ferroelectric, while the centrosymmetric 1Z does not meet the basic requirement for ferroelectricity. Besides, experimental evidence shows that the Z-form can be converted to the E-form by light irradiation. More importantly, the ferroelectric domains of 1E can be manipulated by light in the absence of an electric field, benefiting from the remarkable photoisomerization. 1E also adopts good fatigue resistance to the photocyclization reaction. As far as we know, this is the first example of organic fulgide ferroelectric reported with photo-triggered ferroelectric polarization response. This work has developed a new system for studying photo-triggered ferroelectrics and would also provide an expected perspective on developing ferroelectrics for optical applications in trap future.

Thermostably photoswitchable red fluorescent polymeric nanoparticles for rewritable fluorescence patterning and zebrafish imaging

Photoswitchable fluorescent nanomaterials (PFNs) are gaining popularity in a variety of applications including bioimaging, information encryption and anti-counterfeiting. However, the photoswitching properties of traditional PFNs are still far from application, due to the complex background fluorescence interference, the lower brightness and contrast, the poor thermal and light stability. To tackle this question, we developed new thermostably photoswitchable red fluorescent polymer nanoparticles (TPFPNs) through a facile miniemulsion polymerization in this study. TPFPNs contained a high quantum yield of red fluorescence dye, 1,6,7,12-tetra(p-tBu-phenoxy)-3,4,9,10-di(anhydride) perylene (TBPDI) as donor and a thermostably photochromic diarylethene derivative (DTEDA) as acceptor. When DTEDA changed from its opened-ring state (DTEDA-o) to its closed-ring form (DTEDA-c) after UV irradiation, fluorescence resonance energy transfer (FRET) process occurred from TBPDI to DTEDA-c, which induced the transition from red fluorescence to quenching state. In addition, TPFPNs showed adjustable FRET efficiency, outstanding thermal stability, prominent long-term stability, superior photoreversibility, as well as high contrast of on/off fluorescence. Moreover, TPFPNs were successfully used for photo-rewritable patterning and reversible fluorescence bioimaging in Zebrafish.

Influence of periodic heteroatom substitution in the aryl rings on optical properties and thermal stability of diarylethene derivatives

Photochromic diarylethene derivatives are one of the most promising candidates for various applications in optoelectronic devices. The heteroatom substitution of the aryl groups of diarylethene derivatives could greatly influence their optical properties and thermal stability. For example, the diarylethene derivatives with two thiophene rings (Dithienylethenes) have longer absorption wavelength, better fatigue resistance, sensitivity and thermal bistability than those with two furan rings. To further understand the influence of the heteroatom substitution in aryl rings, a series of diarylethene derivatives with different heteroatoms in IV (C, Si, Ge), V (N, P, As), and VI groups (O, S, Se) of Periodic Table were theoretically explored with DFT/TD-DFT functionals. According to the predicted results, the substituent effects of increasing atomic weights could influence the optical properties, the relative energies, the thermal bistability of the open isomer and the closed isomers. The maximum optical absorptions of the closed isomers and the open isomers could be finely tuned by these heteroatom groups in visible region of 395∼522 nm and in ultraviolet region of 300∼341 nm, respectively. The diarylethene with Se substituent diarylethene was predicted to have the best thermal bistability of all the nine substitutions and also have comparable photochomic properties than widely-used S diarylethene (Dithienylethenes). As 6π-electron system is indispensable part for nearly all known diarylethene derivates, the study probably provides a useful guideline for the future design of novel Se substituent diarylethene compounds with tunable photochromic properties and improved thermal bistability.

Photoinduced cytotoxicity of photochromic symmetric diarylethene derivatives: the relation of structure and cytotoxicity.

Photopharmacology has been attracting attention for the development of drugs with fewer side effects and lower toxicity by introducing a photoswitch structure in the drug and controlling its spatiotemporal effects by light irradiation. Ideally, to achieve precise spatiotemporal control, it is desirable to use photoresponsive molecules that act as anticancer agents based on molecular switch mechanisms at the molecular level. However, very few reports on photoinduced cytotoxicity have used photoresponsive molecules with simple structures. Here, we investigate the photoinduced cytotoxicity of twelve diarylethene derivatives having thiazole or pyridine rings in their molecules and evaluate them in terms of molecular structure and size. Our results provide insight into molecular design principles for diarylethene with a simple structure toward achieving precise control based on molecular-level switch mechanisms.

Mono- and polychromatic light diarylethene-actinometer for the visible range

Photochromes have proven to be attractive molecules for potential applications not necessary based on their spectacular colour change (such as biomimetic chemistry and photoswitchable nucleosides). Their development was incited by the versatility of compounds that could be prepared, but their applications also depended on their photobehaviour. The latter, conceptually requires a comprehensive description of their kinetics. A field which is somewhat still to be developed since, thus far, a single integrated rate-law (c=f(t), expressing the variation of the concentration with irradiation time) has been analytically established for samples exposed to monochromatic light. Similar integrated rate-law equations have yet to be analytically developed for polychromatic light irradiation.The present paper investigates the facets of photokinetics of a photochromic closed-form diarylethene derivative (c-DAE) and its variability with the light type impinging on the sample. An integrated rate-law equation has been derived, to describe kinetics under polychromatic light. The findings have then been applied to establish robust methodologies for both monochromatic and polychromatic light actinometries for the visible range. c-DAE is been shown to be a reliable, easily manipulated, actinometer for the 400–600 nm range for both light types. It is an exemplar of a new generation of actinometers that are easy-to-handle, regenerated, reliable, do not require to have a wavelength-invariant quantum yield, useful for both monochromatic and polychromatic light set-ups, and their procedures are based on integrated rate-law equations.

A highly selective colorimetric and fluorescent probe for Cu2+ based diarylethene with a diaminomaleonitrile unit

A novel photochromic diarylethene derivative containing a diaminomaleonitrile unit (1O) was synthesized and its colorimetric and fluorescent turn-on sensing of Cu2+ in acetonitrile solution was demonstrated. Both of its open- and closed-loop isomers (1O and 1C) were highly selective for Cu2+ with obvious absorption and color transforms. Moreover, the addition of Cu2+ enhanced the fluorescence of 1O up to 174-fold with the concomitant color change from colorless to blue. The limit of detections (LODs) for Cu2+ was determined to be 1.76 × 10−8 mol L−1. The stoichiometry of 1: 1 between the probe 1O and Cu2+ was measured in Job’s plot and ESI-MS. Most remarkably, the probe 1O could be used to detect Cu2+ in test strip.

Geometrical Evolution and Formation of the Photoproduct in the Cycloreversion Reaction of a Diarylethene Derivative Probed by Vibrational Spectroscopy.

The front cover artwork is provided by the groups of Prof. Hiroshi Miyasaka (Osaka University, Japan), Prof. Masahiro Irie (Rikkyo University, Japan), Prof. Seiya Kobatake (Osaka City University, Japan) and Prof. Akira Sakamoto (Aoyama Gakuin University, Japan). The image shows the coherently vibrating closed form of a photochromic diarylethene derivative in the excited state, and subsequent structural evolution into the open form in the cycloreversion reaction. Read the full text of the Article at 10.1002/cphc.202000315.

Front Cover: Geometrical Evolution and Formation of the Photoproduct in the Cycloreversion Reaction of a Diarylethene Derivative Probed by Vibrational Spectroscopy (ChemPhysChem 14/2020)

The Front Cover shows the coherently vibrating closed form of a photochromic diarylethene derivative in the excited state, and subsequent structural evolution into the open form in the cycloreversion reaction. More information can be found in the Article by Hikaru Sotome, Hiroshi Miyasaka, and co-workers.

Fluorescent molecular photoswitch based on basket-shaped porphyrins

Here we present two novel basket-shaped porphyrins bridged by photochromic diarylethene derivatives, which show significant photoswitchable fluorescent properties. Their synthesis, structures, photochromism and fluorescence characteristics were reported in detail. They are desirable for reversible light-driven fluorescent molecular switches.

Photoreversible Birefringence Change of Diarylethene Single Crystals as Revealed by Change in Molecular Polarizability Anisotropy.

Stimuli-responsive organic crystals represent a new frontier of material chemistry. Recently, we have reported photoreversible interference color change to multicolor in single crystals composed of a photochromic diarylethene derivative, 1,2-bis(2-ethyl-5-phenyl-3-thienyl)perfluorocyclopentene (1a), accompanied by the photochromic reaction. The origin of the interference color change is due to the photoinduced birefringence change in the photoisomerization of diarylethenes. In this study, we newly found that single crystals composed of 1,2-bis(2,5-dimethyl-3-thienyl)perfluorocyclopentene (2a) also exhibit a photoreversible interference color change. The birefringence value for crystal 2a increased with the photocyclization conversion, while that for crystal 1a decreased. The relationship between the photoinduced birefringence changes for crystals 1a and 2a and their molecular structures was discussed based on the change in the molecular polarizability anisotropy accompanied by the photochromic reaction. These results would provide not only new opportunities for the application of photochromic crystals but also useful strategies for the design of crystalline materials that exhibit the desired birefringence change.

Multi-responsive molecular switch based on a novel photochromic diarylethene derivative bearing a benzocoumarin unit

A novel photochromic diarylethene derivative bearing a benzocoumarin unit (1O) was synthesized. The derivative exhibits multi-addressable switching characteristics upon the stimulations with lights, proton and metal ions in acetonitrile. The protonated derivative shows good photochromism and photoswitchable fluorescence emission properties. The diarylethene derivative can selectively form a stable 1:1 complex with Cr3+, which triggers the turn-on fluorescence signal. The limit of detection (LOD) for Cr3+ was determined to be 0.013 μM. A molecular logic circuit was successfully constructed based on the fluorescent responses of 1O to different lights and chemicals.

A dominant factor of the cycloreversion reactivity of diarylethene derivatives as revealed by femtosecond time-resolved absorption spectroscopy.

Dynamics of the cycloreversion reaction of a photochromic diarylethene derivative with a small ring-opening reaction yield (∼1%) was investigated by using femtosecond transient absorption spectroscopy. The reaction rate constant and activation barrier on the reaction coordinate were quantitatively analyzed on the basis of the temperature and excitation wavelength dependencies of the reaction yield and excited state dynamics. From the comparison of the present results with those in a more reactive derivative, we concluded that a key factor regulating the overall reaction yield is the branching ratio at the conical intersection where the excited state population is split into the product and the initial reactant. The excitation wavelength dependence of the dynamics indicated that the geometrical relaxation and vibrational cooling proceed in a few picosecond time scale behind the cycloreversion process, and the vibrational excess energy assists the molecule to climb up the energy barrier.

Dual-mode Photochromism of T- and P-types in a Diarylethene Derivative

A photochromic diarylethene derivative having pyrazole and benzothiophene was synthesized and its photochromic behavior and thermal properties were investigated. Upon irradiation with UV light, two...

Photoreversible Interference Color Modulation to Multicolor in Photochromic Molecular Crystals

Abstract Functional molecular crystals responsive to external stimuli represent a new frontier for material chemistry and crystal engineering. Here, we report on the photoreversible interference color change in single crystals composed of a photochromic diarylethene derivative, 1,2-bis(2-ethyl-5-phenyl-3-thienyl)perfluorocyclopentene (1a). When crystal 1a was observed by rotating the sample stage at 45° from the extinction position under crossed Nicols, it showed an interference color. Upon irradiation with ultraviolet (UV) light, the interference color changed dramatically and instantaneously in response to photoirradiation due to the photocyclization reaction from the open-ring form to the closed-ring form. The change was quite sensitive to the photochromic reaction. It is attributable to the large decrease in retardation induced by the photocyclization reaction in crystals. These results might provide new opportunities for application of photochromic crystals.

A Visible-Near-Infrared Light-Responsive Host-Guest Pair with Nanomolar Affinity in Water.

The discovery of stimuli-responsive high affinity host-guest pairs with potential applications under biologically relevant conditions is a challenging goal. This work reports a high-affinity 1:1 complex formed between cucurbit[8]uril and a water-soluble photochromic diarylethene derivative. It was found that, by confining the open isomer within the cavity of the receptor, a redshift in the absorption spectrum and an enhancement of the photocyclization quantum yield from Φ=0.04 to Φ=0.32 were induced. This improvement in the photochemical performance enables quantitative photocyclization with visible light that, together with the near-infrared light-induced ring-opening reaction and the 100-fold selectivity for the closed isomer, confirms this as an outstanding light-responsive affinity pair.

A novel diarylethene-based fluorescent "turn-on" sensor for the selective detection of Mg2.

A new photochromic diarylethene derivative with a 4-methylphenol unit has been designed and synthesized. It displayed distinct photochromism and fluorescent ‘‘turn on’’ features to Mg2+ in acetonitrile solution. With the addition of Mg2+, there was an obvious increase of fluorescent emission intensity at 552 nm, accompanied by a clear change of fluorescent color from dark purple to green. Meantime, the 1 : 1 stoichiometry between the derivative and Mg2+ was verified by Job's plot and HRMS. Furthermore, the sensor was successfully applied in the detection of Mg2+ in practical samples. Moreover, based on the multiple-responsive fluorescence switching behaviors, it also could be used to construct a molecular logic circuit with UV/vis lights and Mg2+/EDTA as input signals and the emission at 552 nm as the output signal.

A new fluorescence probe based on diarylethene with a benzothiazine unit for selective detection of Cd2+

A novel photochromic diarylethene derivative containing a benzothiazine unit has been synthesized. Its photochromism and fluorescent selectivity to metal ions were studied in detail in methanol solution. Under the stimulation of Cd2+ ions, the derivative showed a significant fluorescence enhancement and obvious red shift, accompanied by the fluorescent color changed from dark purple to bright blue. The 1: 1 stoichiometry between the derivative and Cd2+ was verified by titration experiments and high resolution mass spectrometry. In addition, a molecular logic circuit was designed with the emission intensity at 476 nm as output and the stimuli of Cd2+/EDTA and UV/vis as inputs.

A Diarylethene-Based Photoswitch and its Photomodulation of the Fluorescence of Conjugated Polymers.

Photochromic diarylethene derivatives, which can reversibly switch the fluorescence of adjacent fluorophores between the ON and OFF states under light irradiation, have been widely used to construct photoswitchable materials. Herein, eight dithienylethene (DTE) groups are integrated onto one polyhedral oligomeric silsesquioxane (POSS) core, obtaining a novel super molecular photoswitch. After being doped into conjugated polymer nanoparticles, the POSS-DTE8 molecules show a higher contrast on/off photoswitching performance and a quicker responsive speed than free DTE molecules at same molar concentration of photochromic units. This enhanced photoswitching efficiency is attributed to the increased molecular interaction of the ring-open form and lowered energy of the ring-closed form of the DTE units on the POSS core, which is beneficial for the ring-closing reaction and subsequent energy transfer between photoswitch and fluorophores. In addition, POSS-DTE8 also exhibits good photomodulation behavior in the conjugated polymer film, giving it potential applications in optical devices.

A multi-functional fluorescent sensor for Zn2+ and HSO4− based on a new diarylethene derivative

A new photochromic diarylethene derivative with a hydralazine unit was designed and synthesized. It was not only acted as a Zn2+ sensor with the fluorescent color change from dark blue to bright orange, but also acted as a fluorescent sensor for HSO4− with the fluorescent color change from dark blue to bright blue. Furthermore, the derivative also exhibits multi-addressable switching properties by the stimulations of lights and chemical reagents. Based on these characteristics, two combinational logic circuits were constructed with the emission intensity as the output signals, and the UV/vis lights, chemical species as the input signals.