Multi-addressable Switch Research Articles

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 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.

Second-Order Nonlinear Optical Properties of Multiaddressable Indolinooxazolidine Derivatives: Joint Computational and Hyper-Rayleigh Scattering Investigations

The linear and nonlinear optical (NLO) properties of two indolinooxazolidine derivatives acting as multiaddressable switches are reported. The second-order hyperpolarizability contrasts upon commutation between their closed and open forms are characterized using hyper-Rayleigh scattering (HRS) measurements, and rationalized by means of density functional theory and post Hartree–Fock ab initio calculations. It is evidenced that the addition of a withdrawing substituent on the indolinic subunit leads to a more effective photoinduced charge transfer while decreasing the transition energy of the S0 → S1 transition, which induces a significant enhancement of the HRS response of the open form. This substitution is however detrimental to the NLO contrast, due to the concomitant increase of the HRS response of the closed form.

A multi-addressable switch based on the dimethyldihydropyrene photochrome with remarkable proton-triggered photo-opening efficiency.

A series of photochromic derivatives based on the trans-10b,10c-dimethyl-10b,10c-dihydropyrene (DHP, "closed form") skeleton has been synthesized and their photoisomerization leading to the corresponding cyclophanediene (CPD, "open form") isomers has been investigated by UV/Vis and (1) H NMR spectroscopies. Substitution of the DHP core with electron-withdrawing pyridinium groups was found to have major effects on the photoisomerization efficiency, the most remarkable examples being to enhance the quantum yield of the opening reaction and to allow fast and quantitative conversions at much lower radiant energies. This effect was rationalized by theoretical calculations. We also show that the reverse reaction, that is, going from the open form to the closed form, can be electrochemically triggered by oxidation of the CPD unit and that the photo-opening properties of pyridine-substituted DHPs can be efficiently tuned by protonation, the system behaving as a multi-addressable molecular switch. These multi-addressable photochromes show promise for the development of responsive materials.

Photochromism of novel isomeric diarylethenes with benzofuran and pyridine moieties

A new class of isomeric diarylethenes with benzofuran and pyridine moieties was synthesized to investigate the effects of the position of the nitrogen atom in pyridine moiety on their photochromism, acidichromism, and fluorescence. The six-membered pyridine moiety was connected directly to the central cyclopentene ring as an aryl moiety and participated in the photoisomerization reaction in both solution and solid media. These isomeric diarylethenes exhibited multi-addressable switching behavior by the stimulation of acid/base and light. Addition of trifluoroacetic acid to the solutions of these compounds produced the corresponding protonated derivatives. The protonated derivatives exhibited excellent photochromism and notable acidichromism, and the different nitrogen atom position resulted in distinguishable absorption spectra and color changes. The results revealed that the effects of the nitrogen atom position in pyridine moiety played a very important role during the photoisomerization process of these isomeric diarylethenes.

Photochromism of new isomeric pyridine-containing diarylethenes with a benzofuran moiety

Three new isomeric pyridine-containing diarylethenes with a benzofuran moiety were synthesized, and the structures of two diarylethenes were determined by single X-ray diffraction analysis. Their properties such as photochromism, acidchromism, fluorescence, as well as electrochemical properties, were investigated in detailed. The diarylethenes exhibited multi-addressable switching behavior by light and acid/base stimuli in solution and functioned as a remarkable fluorescent switch in both solution and poly(methyl methacrylate) films. Among these isomeric derivatives, the example with the nitrogen atom at the ortho-position of pyridine showed the largest absorption maxima, molar absorption coefficients, and cyclization quantum yield. The nitrogen atom position in the terminal pyridine unit could efficiently modulate the optical and electrochemical properties of the diarylethenes with a benzofuran moiety. The results suggested that the benzofuran moiety and the nitrogen atom position in the terminal pyridine unit played a vital role during the process of photoisomerization reaction for these isomeric diarylethenes.

Synthesis and photochromic properties of novel pyridine-containing diarylethenes

Abstract Three isomeric pyridine-containing diarylethenes were synthesized to study the effects of nitrogen atom position ( ortho , para , meta ) on their photochromic properties. Among these diarylethenes, the example with the nitrogen atom at the ortho -position of pyridine displayed the largest absorption maximum and molar absorption coefficients. The cyclization quantum yields increased in order of para meta ortho , whereas their cycloreversion quantum yields decreased in order of para > meta > ortho . Compared to the diarylethene with terminal phenyl ring, those with a terminal pyridine showed enhanced cyclization quantum yields and emission intensities. Moreover, these pyridine-containing diarylethenes exhibited multi-addressable switching behavior under the stimulation of both proton and light. Addition of trifluoroacetic acid to the solutions of the diarylethenes resulted in notable color change, and their N-protonated forms also possessed excellent photochromism. These results indicated that the nitrogen atom position played a pivotal role in the process of photoisomerization of the diarylethenes.

Photochromism of new unsymmetrical isomeric diarylethenes bearing a pyridine group

A new class of unsymmetrical isomeric diarylethenes bearing a terminal pyridine group was synthesized and their structures were determined by single-crystal X-ray diffraction analysis. The effects of the nitrogen atom position in the pyridine group on their properties including photochromism, acidchromism, and fluorescence were investigated systematically. Among the three isomeric derivatives, the cyclization quantum yield and the absorption maxima of the ortho-substituted diarylethene were the biggest, while the fluorescence quantum yield of the para-substituted diarylethene was the biggest. Furthermore, the three isomeric diarylethenes exhibited multi-addressable switching behaviors by the stimulation of acid/base and light. Addition of trifluoroacetic acid to solutions of these diarylethenes produced the protonated derivatives, which also showed excellent photochromic behaviors, but only the para-substituted diarylethene exhibited a notable color change of solution from crimson to violet. The results revealed that the effects of the nitrogen atom position in the terminal pyridine group played a very important role during the process of photoisomerization for these isomeric diarylethene derivatives.

Multi-addressable molecular switches based on photochromic diarylethenes bearing a rhodamine unit

Two novel diarylethene derivatives bearing a rhodamine unit have been successfully synthesized. Their unique multi-addressable switching characteristics as induced by chemical and optical dual inputs stimulation were observed using UV and FL measurements. The two diarylethenes showed excellent photochormism with alternating UV/vis light irradiation. Addition of trifluoroacetic acid (TFA) protonated the diarylethenes, which resulted in good photochromism and notable fluorescence change via the FRET mechanism. Subsequent addition of triethanolamine base would neutralize and return both their protonated open-ring and closed-ring isomers to their original forms. It was found that the diarylethene bearing a rhodamine unit linked by a benzhydrazide bridge group was more sensitive, efficient and reacted faster to protonation by TFA when compared to the benzamide bridged derivative. Furthermore, the benzhydrazide bridged diarylethene derivative was found to be selective towards Cr(III), Al(III), or Ca(II) with significant color and fluorescence changes.

Diarylethene–dihydroazulene multimode photochrome: a theoretical spectroscopic investigation

Using Time-Dependent Density Functional Theory, we have assessed the structural, energetic and spectroscopic properties of a hybrid diarylethene-dihydroazulene multi-addressable switch synthesized by Mrozek et al. [Chem. Commun., 1999, 1487-1488]. All possible closed/open structures have been considered and the different activation barriers along each reaction path have been evaluated. The determination of the energetic profiles allowed us to pinpoint the thermally possible reactions. To simulate the electronic absorption spectra of this compact two-way four-state hybrid compound, we relied on a PCM-TD-DFT approach combined with a molecular orbital analysis. Key insights are reached and the experimental photochromic properties of this multi-component switch are rationalised. From a more methodological point of view, this work also shows that range-separated hybrid functionals (CAM-B3LYP and ωB97XD) allow to reproduce the measured spectroscopic features with a remarkable accuracy.

Construction and properties of multi-addressable switching system based on a photochromic diarylethene

A multi-addressable switching system has been constructed by employing photochromic diarylethene 1a, which is obtained by coupling photochromic 3,4-bis(5-formyl-2-methylthien-3-yl)-2,5-dihydrothiophene with 8-hydroxy-2-methylquinoline, as model compound. It is found that 1a exhibits ring-opening and ring-closing photoisomerization with UV/Vis light irradiation. Addition of trifluoroacetic acid to solution of 1a produces protonated diarylethene 2a, and 2a also performs photochromic behavior with distinguished color change. Both protonated ring-open isomer 2a and ring-closed isomer 2b reverse back to 1a and 1b by neutralization with base solution. Besides, a complex diarylethene 3a is formed when boron trifluoride diethyl etherate is added to a solution of 1a, and it is found that 3a also undergoes excellent photoisomerization.