Photochromic Diarylethene Research Articles

Phototunable Cell Killing by Photochromic Diarylethene of Thiazoyl and Thienyl Derivatives.

We report a unique phototunable cell killing technique using diarylethene molecules as photo-isomerizing-molecular switches. These molecules were delivered to DNA in the cell nucleus due to closed-form generated by UV light, and then blue light triggered cell killing. A UV light irradiation switches the open form, having no DNA intercalation activity, to the closed form to induce intercalation in DNA. This isomer, thus prepared ready for the action, exerts photocytotoxicity upon the subsequent blue light irradiation. Molecular biological analysis clarifies that photocytotoxicity is due to DNA double-strand breaks. Since cell death is observed only when irradiated with light where both the open- and closed-ring isomers have absorption, the possible mechanism of cell death is assumed to be due to the repeated photocyclization and photocycloreversion reactions of the diarylethene molecules, which induce irreparable damage to DNA. This unique photo-controllable action in a cell system can provide the basis of a novel scheme of phototherapy.

Mathematical modeling of morphological changes in photochromic crystals by catastrophe theory

Photochromic diarylethene is known to exhibit reversible photoisomerization under irradiation with ultraviolet (UV) and visible light. Besides reversible optical properties upon light irradiation, a variety of discontinuous morphological changes of the crystals are reported in the literature, such as sudden crystal bending, cracking, and photosalient effects, which are caused simply by UV and visible light irradiation. These morphological phenomena with discontinuities are micro-scale changes caused by photoisomerization of molecules at the nanoscale and lead to the realization of important functions for optical devices. However, the theoretical models behind these phenomena are not well understood. In this paper, we construct a mathematical model that can treat diverse phenomena in a unified model by using swallow-tail catastrophe, a higher-order catastrophe than cusp catastrophe, from the seven elementary catastrophes that can describe discontinuities in the phenomena. By introducing hyperbolic operating curves in the model, the intrinsic properties of the photochromic crystals are represented. The induced morphogenesis, such as bending, cracking, and photosalient effects, are systematically classified by the proposed catastrophe model, which even implies the possibility of unexplored operating conditions of the crystals and explains known phenomena. The proposed catastrophe-theory-based modeling provides a foundation for understanding and discovering the versatile morphogenesis in photochromic crystals. Furthermore, the proposed approach provides a basis for understanding and discovering various morphological changes in photochromic crystals and similar systems.

Efficient Surface Peeling, a Photoinduced Result of Photochromic Diarylethene Crystal by Multistep Light Irradiation

Efficient Surface Peeling, a Photoinduced Result of Photochromic Diarylethene Crystal by Multistep Light Irradiation

Reconfigurable photoswitchable multistate fluorescent polymer-based information encryption toolbox

High-performance information encryption materials are crucial for developing advanced technologies that prevent information leakage and combat fraud. These materials must be robust, intelligent, and easily programmable. To meet these criteria, we developed an information encryption toolbox based on a series of novel self-healing photoswitchable dual (P1 and P2) and multistate (P3) fluorescent polymers using two photochromic fluorescent diarylethenes, i.e., 4-hydroxybutyl acrylate link 1,2-bis(2-methyl-1-benzothiophene-1,1-dioxide-3-yl)perfuoro-cyclopentene (SDTE), 4-(acryloyloxy)butyl 4-oxo-4-butanoate link 2,3-bis (2-methylbenzo[b]thiophen-3-yl)-5,6-dihydro-4H-thieno[2,3-b]thiopyran-4-one (BTBA) and hydrogen-bonding units, i.e., 2-ureido-4[1H]-pyrimidinone (UPy). Upon irradiation with different wavelength lights, P1/P2 can be alternated between green/red and quenched states, while P3 can be switched among red, green, and quenched states. Using these polymers to fabricate pixel units can produce reconfigurable patterns and codes displaying good mechanical properties and excellent optical characteristics, including rapid photoresponsiveness, robust photoreversibility, superior fluorescent thermal stability, and strong resistance to acid and base corrosion. Furthermore, we also demonstrated the immediate application opportunities of our toolbox in three-dimensional-code arrays and quick response codes.

A dual-channel chemosensor based on diarylethene bearing a benzoisothiazole unit for detecting CO32−

A new photochromic diarylethene with a benzoisothiazole unit has been designed and synthesized. The diarylethene could act as a colorimetric and fluorescence dual-channel chemosensor for CO32− with short response time, high selectivity, and excellent sensitivity. Moreover, the response mechanism of the chemosensor to CO32− was studied systematically in methanol. The chemosensor could be used to the detection of CO32− in practical water samples, and also be made into test papers for CO32− recognition with high efficiency.

Visible-light-driven bistable photoswitching with enhanced solid state NIR-fluorescence for multi-level optical storage

A visible-light driven solid-state NIR fluorescent bistable molecular switch was constructed by coupling bulky tetraphenylethylene, photochromic diarylethene and NIR emissive terrylene diimide. Multi-level optical storage was demonstrated based on its film.

Photochromic diarylethene induced fluorescence switching materials constructed by non-covalent interactions

This review summarizes recent developments of diarylethene-based photochromic fluorescence switches constructed by non-covalent interactions, and the structural design principles of diarylethenes and fluorophores are discussed.

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.

Dual and Sequential Locked/Unlocked Photochromic Effects on FRET Controlled Singlet Oxygen Processes by Contracted/Extended Forms of Diarylethene-Based [1]Rotaxane Nanoparticles.

Manipulations of singlet oxygen (1 O2 ) generations by the integration of both aggregation-induced emission luminogen (AIEgen) photosensitizer and photochromic moieties have diversified features in photodynamic therapy applications. Through Förster resonance energy transfer (FRET) pathway to induce red PL emissions (at 595nm) for 1 O2 productions, [1]rotaxane containing photosensitive tetraphenylethylene (TPE) donor and photochromic diarylethene (DAE) acceptor is introduced to achieve dual and sequential locked/unlocked photoswitching effects by pH-controlled shuttling of its contracted/extended forms. Interestingly, the UV-enabled DAE ring closure speeds follow the reversed trend of DAE self-constraint degree as: contracted < extended < noninterlocked forms in [1]rotaxane analogues, thus FRET processes can be adjusted in contracted/extended forms of [1]rotaxane upon UV irradiations. Accordingly, the contracted form of [1]rotaxane is FRET-OFF locked and inert to UV exposure due to the larger bending conformation of DAE parallel (p-)conformer, compared with its extended and noninterlocked analogues possessing switchable FRET-OFF/ON behaviors activated by dual and sequential pH- and photoswitching. Owing to the advantages of 1 O2 productions tuned by multistimuli inputs (pH, UV, and blue light), an useful logic circuit for toxicity outputs of the surface modified [1]rotaxane nanoparticles (NPs) has been demonstrated to offer promising 1 O2 productions and managements based on mechanically interlocked molecules for future bioapplications.

Switchable single-molecule electronic and thermoelectric device induced by light in a designed diarylethene molecule

Tremendous efforts have been devoted to studying ordinary and novel properties in molecular-scale. Especially the reversible and controlled electrical and thermoelectric switches, which have been extensively studied experimentally and theoretically. They possess two distinct electronic and thermoelectric transport states actuated by external triggers, such as light, temperature, and electric field. Here, a photochromic diarylethene, linked to a nontriazatriangulene platform covalently, is studied by first-principles calculation. By means of density functional theory, we calculate the density of states and scanning tunneling microscope (STM) images of the designed diarylethene adsorbed on a Au(111) surface. Moreover, the thermoelectric transport properties of diarylethene-based molecular junction with a Au(111) electrode are studied systematically by using nonequilibrium Green's function transport formalism. We illustrate that due to the structure chang e of the designed diarylethene induced by light, the electronic and thermoelectric transport properties of the junction are completely different. Those differences can be visualized by the calculated electronic transmission eigenchannel and transport pathway. Furthermore, we demonstrate that the structure change of the designed diarylethene can be detected by STM experiments. The present study shows that the designed diarylethene could be a desirable candidate for electronic and thermoelectric molecular switch driven by light.

Phototunable Golden Luster Microcrystalline Film of Photochromic Diarylethene

Abstract This study presents phototunable organic golden luster material. We adopted photochromic diarylethene to produce this material. Through recrystallization, the compound formed plate-like microcrystals, which were then laminated to form a film. The yellowish gold-colored textured film was achieved by a combination of diarylethene absorption and specular reflection from the surface of the stacked microcrystals. The produced films showed a change in color to deep gold upon UV light irradiation due to the change in the absorption band caused by the photocyclization of diarylethene. The film reverted to its original color upon exposure to visible light due to the photocycloreversion of the diarylethene. Such photoresponsive metallic luster in a material could have a significant impact on applications in the decoration and ink industries by avoiding the use of actual precious metals.

Effect of Substrate Surfaces for Crystal Growth of a Photochromic Diarylethene by Sublimation

The state of the substrate surface is one of the key factors in varying morphologies of crystals produced by the sublimation method of some organic compounds. In this work, we succeeded in separately preparing different morphologies of rodlike crystals of 1,2-bis(2,5-dimethyl-3-thienyl)perfluorocyclopentene (1a), which are classified into the hollow crystal and the feather-like crystal, by sublimation to glass substrates with the hydrophilic and hydrophobic surfaces, respectively. To clarify the crystal growth process on each surface of the glass substrate, we investigated miller indices of crystal faces attached to the substrate surface in the early stage of sublimation and crystal growth directions of these rodlike crystals from these crystal faces by X-ray diffraction measurements and polarizing microscopic observation. As a result, it was revealed that the heterojunction between the crystal faces produced in the early and following stages of sublimation leads to two different crystal morphologies. Moreover, it was confirmed that the heterojunctions occur in a specific orientation between these crystal faces because the lattice points in these crystal faces are in good agreement. Finally, we have demonstrated photomechanical behaviors of the hollow and feather-like crystals.

A Highly Selective Hg2+ Fluorescent Chemosensor Based On Photochromic Diarylethene With Quinoline Unit.

A novel diarylethene-based fluorescent chemosensor containing a quinoline unit (1o) had been designed and synthesized. 1o showed good photochromic ability and fluorescence switching properties by alternating UV/vis light irradiation. The chemosensor showed high "Turn-off" fluorescent selectivity for Hg2+ by competitive tests of the fluorescence reaction in the presence other ions in acetonitrile solution. The stoichiometry between the compound 1o and Hg2+ was 1:1 by Job's plot curve and HRMS analysis. In addition, the LOD for Hg2+ was calculated as 60nM. The fluorescence emission can be back to the "Turn-on" state by adding EDTA. Based on these facts, a molecular logic gate that including four input signals (UV/vis and Hg2+/EDTA) and one output signal (fluorescent intensity at 491nm) was designed.

All-Visible (>500 nm)-Light-Induced Diarylethene Photochromism Based on Multiplicity Conversion via Intramolecular Energy Transfer.

Photoswitching molecules that reversibly switch upon visible-light irradiation are some of the most attractive targets for biological and imaging applications. In this study, we found a diarylethene (DAE) derivative having a covalently attached perylenebisimide (PBI) unit (DAE-PBI dyad) underwent an unexpected cyclization reaction upon irradiation with green (500-550 nm) light, where the DAE unit has no absorbance. The photoreactivity was enhanced in solvents containing heavy atoms and in the presence of oxygen. As inferred from the solvent dependence and the calculated excited-state energies of DAE and PBI units, it was suggested that the probable mechanism for this unique visible-light-induced cyclization reaction is multiplicity conversion based on intramolecular energy transfer from the excited singlet state of the PBI unit to the triplet state of DAE units (i.e., DAE-1[PBI]* → 3[DAE]*-PBI). Such a unique photoreaction mechanism with the assistance of oxygen will pave the way for new molecular design for the development of visible-light switching molecules.

Construction of a photo-controlled fluorescent switching with diarylethene modified carbon dots

Photo-controlled fluorescent switching is of great utility in fluorescence sensors, reversible data storage, and logic circuit, based on their modifiable emission intensity and spectra. In this work, a novel photo-controlled reversible fluorescent switching system was constructed based on photochromic diarylethene (DT) molecular modified fluorescent carbon dots (CDs). The fluorescent CDs acted as fluorescent donors and the photochromic diarylethene molecular functioned as acceptors in this fluorescent switching system. The fluorescence modulation efficiency of the fluorescent switching was determined to be 97.1%. The result was attributable to Förster resonance energy transfer between the CDs and the diarylethene molecular. The fluorescent switching could undergo 20 cycles without significant decay.

Multistimuli-responsive hydrogels with both anisotropic mechanical performance and anisotropic luminescent behavior

Anisotropic luminescence emission is the basis to achieve some key parameters in optoelectronic fields. As compared with mechanical anisotropy, however, achieving anisotropic emitting behavior is still challenging. Thus, integrating multiple stimuli into one luminescent hydrogel orthogonally while retaining its anisotropic structure remains an open challenge. Herein, we report the construction of a multistimuli-responsive mechanical/luminescent dual anisotropic hydrogel through the copolymerization of superparamagnetic nanoparticle-coated alumina (Fe/Al2O3) platelets, lanthanide complex, photochromic diarylethene molecule, and N-isopropylacrylamide (NIPA) in an oriented magnetic field. The aligned Fe/Al2O3 platelets impart the hydrogel an anisotropic mechanical property, and the orientation-dependent “shading effect” of the aligned Fe/Al2O3 platelets on the lanthanide complex also endow the hydrogel with anisotropic emission behavior. Significantly, photoreversible luminescence on/off switch and thermoreversible anisotropic deformation are realized in the hydrogel based on the conformation-dependent fluorescence resonance energy transfer between the lanthanide donor and photochromic diarylethene acceptor, and phase transition of polymerized NIPA, respectively. As a proof-of-concept, multidimensional intelligent anticounterfeiting is demonstrated by using this hydrogel. Thus, this work demonstrates a general preparation strategy of multistimuli-responsive dual anisotropic hydrogels for purposely designed applications, offering insights in the field fundamentally and practically.

Site‐specific fabrication of gold nanocluster‐based fluorescence photoswitch enabled by the dual roles of albumin proteins

AbstractFluorescence photoswitch is becoming increasingly desirable for many applications, but its controllable fabrication still remains challenging yet. In this paper, a new strategy is proposed to fabricate fluorescence photoswitch by harnessing dual roles of albumin proteins as both photochrome carriers and biotemplates of fluorophore. As an example, we demonstrated the successful fabrication of a fluorescence photoswitch by incorporating both the photochromic diarylethene dye (CMTE) and red‐emitting fluorescent gold nanoclusters (AuNCs) into the specific domains of bovine serum albumin (BSA) in a highly controllable manner. Detailed spectral and photophysical characterisation showed that CMTE well‐retains the photochromic properties within the CMTE–BSA–AuNC construct, although its photoconversion rate is slightly retarded. Different from previously reported photoswitches, the fluorescence of the present system is mainly modulated via the inner filter effect (IFE) mechanism, which exhibits high switching efficiency with an on–off ratio up to 90%, reversible fluorescence response and good antifatigue performance. This work provides a new, generable albumin protein‐assisted strategy of fabricating advanced fluorescence photoswitch, which can find wide applications in biological, optical and information fields.

Gated photochromic reactivity of diarylethenes with visible-light-triggered turn-on fluorescence

All visible-light-driven fluorescent photo-switches are essential for high-density optical memories, whereas their gated photochromism remains a great challenge. Herein, we report the synthesis and photochromic properties of 2,3-bis(2-methyl-1-benzothiophene-1,1-dioxide-3-yl)-thiophene (BTTO4) based photochromic diarylethene isomers oDB, mDB, and pDB functionalized with N,N-dimethylaniline at three positions. These compounds all exhibit turn-on fluorescence upon visible light irradiation at 405 nm. Surprisingly, the cycloreversion reaction of para-substituted closed-isomer c-pDB was suppressed. Upon addition of trifluoroacetic acid, the acidic compound c-pDB•H+ was turned active, displaying an unusual gated photochromic property. Moreover, the photochromic reactivity can be suppressed again by neutralizing the acid with Et3N. To the best of our knowledge, this is the first report of gated photochromic diarylethene with visible-light-triggered turn-on fluorescence. This study provides a new type of all-visible-light triggered fluorescent photo-switches, and a novel “lock” and “unlock” system for photocycloreversion reactions.

CALCULATION OF THE FÖRSTER RESONANCE ENERGY TRANSFER PARAMETERS IN NANOSPHERES CONTAINING CdSe/ZnS QUANTUM DOTS AND DIARYLETHENE

An analysis of theoretical model studies of photochromic systems with reversible fluorescence modulation based on polymer nanospheres containing CdSe/ZnS semiconductor quantum dots (QDs), and photochromic diarylethene DAE2 molecules is presented. Based on the known relations of the theory of Förster resonance energy transfer (FRET), a model is constructed for the efficiency of modulation of QD fluorescence E(r) caused by photochromic transformations of DAE2 molecules located near them due to the FRET mechanism. The boundaries of the optimal values of the parameters that affect the efficiency of the fluorescence modulation due to FRET are determined. The efficiency of FRET E(r) is given for some boundary values of the influencing factors. It is shown that E(r) ~ 0.7 can be achieved at distances between donors and acceptors r = 4.5 nm, if one QD with a fluorescence quantum yield Q = 0.4 accounts for at least n = 16 DAE2 molecules (or at Q = 0.8 and n = 8), as well as at distances r = 3 nm (Q = 0.1 and n = 6; Q = 0.4 and n = 2; Q = 0.8 and n = 1). The results obtained can be used to optimize the structure and technology for the synthesis of photochromic luminescent nanospheres.

Construction of reversible fluorescent switching systems with CdSe quantum dots and photochromic diarylethenes

A series of light controlled and reversible fluorescent switching systems have been constructed with CdSe quantum dots (CdSe-QDs) and three photochromic diarylethene molecules with different functional groups. The CdSe-QDs acted as energy donor, and the diarylethene molecules served as reversible photoactive energy acceptors. The results showed that all of the diarylethenes could modulate the fluorescence of CdSe-QDs efficiently by the irradiation of UV/vis lights. It is worth mentioning that the quenching efficiency of each fluorescence switch was greater than 50% for the three systems. In addition, the switching properties, fluorescence modulation efficiency, and fatigue resistance of the three systems were studied systematically. The modulation efficiency of the three switches was 76.9%, 89.5%, and 59.0% respectively. It is obvious that the diarylethene with a formyl group has the maximum fluorescence modulation efficiency, and the symmetrical diarylethene with a phenyl group at the end has the best resistance to fatigue.