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A colorimetric and fluorescent chemosensor for Hg <sup>2+</sup> based on a photochromic diarylethene with a quinoline unit
摘要： A new colorimetric and fluorescent 'on–off' chemosensor, 1O, based on a photochromic diarylethene with a quinoline unit was designed and synthesized. The chemosensor 1O demonstrated selective and sensitive detection of Hg2+ ions in the presence of other competitive metal ions in acetonitrile. The stoichiometric ratio of the sensor 1O for Hg2+ was determined to be 1 : 1, and the limit of detection of the probe 1O was calculated to be 56.3 nM for Hg2+. In addition, a molecular logic circuit with four inputs and one output was successfully constructed with UV/vis light and metal-responsive behavior. ESI-MS spectroscopy, Job's plot analysis, and 1H NMR titration experiments confirm the binding behavior between 1O and Hg2+.
关键词： quinoline,logic circuit,fluorescent,Hg2+,colorimetric,diarylethene,chemosensor,photochromic
更新于2025-09-19 17:15:36
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Morphological evolution of Co phosphate and its electrochemical and photocatalytic performance
摘要： Three novel 3D calcium-based metal–organic frameworks (FJU-67, FJU-68, and FJU-69) established on naphthalene diimide chromophores have been synthesized, which exhibit unique multiple interpenetrated networks with dia net topologies. It is noticeable that the shape and size of the second carboxylic ligands can directly influence the mode of the interpenetrated frameworks. Linear dicarboxylic acid H2BDC or NH2-H2BDC ligands can yield 5-fold interpenetrated frameworks, while 2,6-naphthalenedicarboxylic acid (H2NDC) ligand with a longer length and slight angle can produce a 4-fold (2 + 2) framework. Among the three Cd-MOFs, FJU-67 and FJU-69 with a relatively pale color exhibit reversible photochromism via the radical formation of NDI units and interpenetrating packing has a definite impact on their photochromic behaviors.
关键词： photochromic,Cd-MOFs,interpenetrated frameworks,naphthalene diimide,second dicarboxylic acid ligands
更新于2025-09-19 17:15:36
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A dominant factor of the cycloreversion reactivity of diarylethene derivatives as revealed by femtosecond time-resolved absorption spectroscopy
摘要： 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.
关键词： vibrational cooling,diarylethene derivative,photochromic,femtosecond transient absorption spectroscopy,cycloreversion reaction
更新于2025-09-19 17:13:59
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Modulating the luminance of organic light-emitting diodes via optical stimulation of a photochromic molecular monolayer at transparent oxide electrode
摘要： Self-assembled monolayers (SAMs) deposited on bottom electrodes are commonly used to tune charge carrier injection or blocking in optoelectronic devices. Beside the enhancement of device performance, the fabrication of multifunctional devices in which the output can be modulated by multiple external stimuli remains a challenging target. In this work, we report the functionalization of an indium tin oxide (ITO) electrode with a SAM of a diarylethene derivative designed for optically control the electronic properties. Following the demonstration of dense SAM formation and its photochromic activity, as a proof-of-principle, an organic light-emitting diode (OLED) embedding the light-responsive SAM-covered electrode was fabricated and characterized. Optically addressing the two-terminal device by irradiation with ultraviolet light doubles the electroluminescence. The original value can be restored reversibly by irradiation with visible light. This expanded functionality is based on the photoinduced modulation of the electronic structure of the diarylethene isomers, which impact the charge carriers’ confinement within the emissive layer. This approach could be successfully exploited in the field of opto-communication technology, for example to fabricate opto-electronic logic circuits.
关键词： photochromic,optoelectronic devices,diarylethene,Self-assembled monolayers,organic light-emitting diodes
更新于2025-09-19 17:13:59
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Photoinduced Modulation of the Emission from СdSe/ZnS Quantum Dots by Photochromic Transformations of Diarylethenes
摘要： A spectral study of the interaction between the molecules of photochromic compounds of the diarylethene class and CdSe/ZnS quantum dots (QDs), in dependence of the structure and nature of functional substituents of photochromes, has been performed. It is shown that both chemical and physical interactions are accompanied by photoinduced modulation of QD emission as a result of photochromic transformations of diarylethenes caused by the inductive transfer of excitation energy from QDs to the diarylethene cyclic isomer.
关键词： diarylethenes,CdSe/ZnS quantum dots,nanomaterials,photoinduced modulation,photochromic transformations,ceramics
更新于2025-09-12 10:27:22
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Photo-Switchable Boronic Acid Derived Salicylidenehydrazone Enabled by Photochromic Spirooxazine and Fulgide Moieties: Multiple Responses of Optical Absorption, Fluorescence Emission, and Quadratic Nonlinear Optics
摘要： A novel protocol of the boronic acid derived salicylidenehydrazone (BASHY) core being sandwiched by photochromic spirooxazine and fulgide moieties was proposed here to design multistate fluorescent photoswitches with variable nonlinear optical (NLO) responses. Systematic investigations on their optical absorption, fluorescence emission, and static first hyperpolarizabilities (β) were performed using density functional theory (DFT). It was found that the BASHY-based sandwiched series exhibited significant differences of absorption and emission properties between three photoisomers, which were essentially ascribed to the massive changes of corresponding electron transition characteristics quantified by hole–electron descriptors and visualized by electron density difference (EDD) plots. However, the isomerization of fulgide parts in the merocyanine (MC) form of spirooxazine failed to greatly shift maximum absorption/emission wavelengths, due to their high similarity of intrinsic transition features. Furthermore, large β contrasts between three photoisomers were observed, which resulted from significant variations of contributions of spirooxazine and/or fulgide moieties to the total β upon photoisomerization according to β densities. Although the fulgide moiety contributes negatively and positively to spirooxazine (SO) isomers when fulgide switches from close (C-) to open (E-) forms, respectively, their dominant βxxx values with opposite signs are still similar in magnitude, leading to quite close quadratic NLO responses. Therefore, the captivating ternary photoswitches with multiple responses of absorption, emission, and NLO were elaborately built in this context, promising to be applied as multifunctional optical materials in various scientific and technological fields.
关键词： photochromic spirooxazine,fulgide moieties,nonlinear optical (NLO) responses,density functional theory (DFT),boronic acid derived salicylidenehydrazone (BASHY)
更新于2025-09-12 10:27:22
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The processes underlying the laser photochromic effect in colloidal plasmonic nanoparticle aggregates
摘要： We have studied the dynamic and static processes occurring in disordered multiparticle colloidal Ag aggregates with natural structure and affecting their plasmonic absorption spectra under pico- and nanosecond pulsed laser radiation, as well as the physical origin responsible for these processes. We have shown that depending on the duration of the laser pulse, the mechanisms of laser modification of such aggregates can be associated both with changes in the resonant properties of particles due to their heating and melting (picosecond irradiation mode) and with the particle shifts in resonant domains of aggregates (nanosecond pulses) which depend on the wavelength, intensity and polarization of the radiation. These mechanisms results in formation of a narrow dip in the plasmonic absorption spectrum of aggregates near the laser radiation wavelength and affect the shape and position of the dip. The effect of polydispersity of nanoparticle aggregates on laser photochromic reaction has been studied.
关键词： Nanoparticle,surface plasmon resonance,photochromic process,pulsed laser radiation
更新于2025-09-12 10:27:22
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Optically controlled field effect transistors based on photochromic spiropyran and fullerene C60 films
摘要： Optically controlled organic field effect transistors containing a binary mixture of fullerene C60 (n-semiconductor) and spiropyran (photoresponsive conductivity modulator) as the active layer were designed and fabricated. The obtained transistors demonstrated higher transfer characteristics (source-drain current), charge carrier mobility in the active layer, and response rate to an external influence than the multilayer transistor (wherein these semiconductor and photo responsive material are in different layers), which makes them promising candidates for the design of optical memory elements.
关键词： Optically controlled field effect transistors,photochromic spiropyran,fullerene C60,optical memory elements
更新于2025-09-12 10:27:22
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Nucleation mechanism of metal-vapor atoms on photochromic diarylethene surface with a low glass transition temperature
摘要： Metal pattern formation on organic surfaces is essential in organic electronics. Selective metal-vapor deposition using photochromic diarylethene (DAE) is a promising method to prepare ?ne metal patterns by maskless evaporation. Metal-vapor atoms are adsorbed, di?used, and then desorbed from the colorless surface with a low glass transition temperature. We, however, found that metal deposition started at a speci?c time (deposition-threshold time, tth) even on the colorless surface by continuous evaporation. tth was investigated using a quartz crystal microbalance. We elucidated that metal-nucleation sites were generated by chemical reactions between metal atoms and surface DAE molecules. The number of nucleation sites increases during metal evaporation and when the sites are located in the di?usion range of surface metal atoms, metal-atom nucleation for ?lm-formation starts. This is the origin of tth. This result would provide important knowledge for the preparation of electrodes for organic devices based on selective metal-vapor deposition.
关键词： organic electronics,nucleation mechanism,photochromic diarylethene,quartz crystal microbalance,metal-vapor deposition
更新于2025-09-10 09:29:36
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Metal Oxide Nanostructures || Chromogenic applications
摘要： There exist several forms of chromism, but this chapter only describes the phenomena that involve metal oxide materials. Chromism refers to changes in visible optical properties in response to an external stimulus such as electrical, optical, thermal, or mechanical [1]. It includes changes in color or intensity. It can also refer to a transition from transparent to a scattering reflective state. The chromogenic family of materials has been ever expanding over the past few years, with the development of new materials and nanomaterials. A schematic of the evolution of chromogenic effect and materials is shown in Fig. 4.1.
关键词： metal oxide materials,photochromic,chromism,gasochromic,electrochromic,thermochromic,magnetochromic
更新于2025-09-10 09:29:36