香兰素席夫碱的合成和光致变色性

以香兰素和邻苯二胺为原料合成了席夫碱,以质谱和核磁等手段进行了结构表征。该化合物有较好的光致变色性,其分子结构在紫外-热或者酸-碱作用下,可发生可逆循环变化过程。文中探讨了紫外、热、酸碱度对化合物结构的影响,及其引起的光谱性质的变化,结果表明,它有望应用于信息存储材料领域。     

十八烷基取代吲哚啉螺吡喃衍生物的合成及光谱性质

本文合成了十种新的十八烷基取代的吲哚螺吡喃衍生物,拟进一步研究这类化合物在LB膜中的光致变色性质.     

Crystal structure and photochromism of 1-phenyl-3-methyl-4-benzyl-5-one-pyrazole S-methyl thiosemicarbazone

A new organic photochromic compound containing pyrazolone-ring photochromic functional unit: 1-phenyl-3-methyl-4-benzyl-5-one pyrazole S-methyl thiosemicarbazone (PMBP-smtsc) was synthesized. The photochromic properties and photochemical kinetics of PMBP-smtsc have been studied by UV reflectance spectra under irradiation of 365 nm light. The crystal structure analyses of photocolored product show the photochromism is due to the photoisomerization from enol form to keto form through an intermolecular proton transfer.     

UV-light and visible-light photochromism of inorganic–organic multilayer films based on polyoxometalate and poly(acrylamide)

Novel UV-light and visible-light photochromic inorganic–organic multilayers composed of polyoxometalates (phosphomolybdic acid (PMoA)) and poly(acrylamide) (PAM) were prepared by the layer-by-layer (LbL) self-assembly method. The grown process, composition, surface topography, and photochromic properties and mechanism of the multilayer films were investigated by ultraviolet–visible (UV–vis) spectra, Fourier transform infrared spectra (FT-IR), atomic force microscopy (AFM), electron resonance spectra (ESR), and X-ray photoelectron spectra (XPS). Irradiation with UV-light or visible-light, the transparent films changed from colorless to blue and showed reversible photochromism. PMoA/PAM LbL films had higher photochromic efficiency under UV-light irradiation than visible-light irradiation. The bleaching process occurred when the films were in contact with O₂ in the dark or heated in air. The photochromic process of PMoA/PAM LbL film was in accordance with radical mechanism.     

Keggin结构钨磷酸/聚乙烯吡咯烷酮复合膜的制备和光致变色性质研究

近年来,由于无机－有机复合材料具有潜在的应用前景和特殊性能,尤其是光致变色性能,引起研究者们的广泛兴趣^[1-3],以杂多化合物为多核配合物,通过化合键或氢键作用与高分子底物结合,形成电荷转移物质,可以大大提高复合材料的化学和物理性能。目前,这一领域的研究在国外已经成为热点^[4-7]。本文以Keggin结构钨磷酸和聚乙烯吡咯烷酮为原料,报道了该类复合物的合成、表征及光致变色性质。     

Structure and solid-state photochromic properties of two new compounds with pyrazolone-ring

Two new organic photochromic compounds based on pyrazolone were synthesized and further characterized by elemental analysis, MS, IR spectra, and ¹H NMR spectra. The photochromic properties and photochemical kinetics of them have been studied by UV absorption spectra under irradiation of 365 nm light. The photochromism of pyrazolone derivatives in the solid state has been so far explained only in terms of the light-induced change of absorption and their crystal structures, which is caused by the shift of the tautomeric equilibrium between the enol and keto forms. In this work, their IR spectra have been measured before and after irradiation. Based on the IR spectra and crystal structure analysis, a reasonable mechanism was proposed, the photochromic phenomenon may be due to the photoisomerization from enol-form to keto-form through proton transfer.     

镶嵌钨硅酸的新型有机-无机纳米复合薄膜的制备及光致变色性能研究

将超分子自组装技术与Sol-gel过程相结合,制备了镶嵌Keggin结构钨硅酸的MAAM/VTEOS/TEOS纳米复合薄膜,并采用IR,XRD和TG-DSC等方法对薄膜进行了结构表征.在复合薄膜光照变蓝后,通过UV-Vis和ESR光谱对薄膜的光致变色性能及其机理进行了研究.结果表明,钨硅酸在复合网络中仍保持Keggin结构,与有机-无机复合基体中的-NH₂通过氢键发生强烈的相互作用,经紫外光照后发生电荷转移,[SiW₁₂O₄0]₄^-被还原为[SiW₁₂O₄0]₅^-,同时产生氨基自由基.褪色过程则与氧气存在与否有关,实验结果表明,该薄膜具有良好的光致变色性能,对光有较快的响应恢复速度和良好的可逆重复性.     

乙二铵多钼酸盐NH3CH2CH2NH3Mo3O10·4.4H2O的 合成及其光致变色性质研究

利用乙二胺阳离子为模板,采用温和的反应条件制备出一种新的光致变色化合物NH3CH2CH2NH3Mo3O10·4.4H2O,经过元素分析、热重以及光谱测定,证明该化合物的无机骨架为(Mo3O10)∞^2-无穷长链。乙二胺阳离子通过氢键等超分子作用与无机骨架相连。实验发现该化合物具有良好的光致变色性能,与真空蒸镀MoO3不同的是,经紫外光照后,此化合物由白色变为红棕色,EXAFS(扩展X射线精细结构)研究结果表明紫外光照后,质子从乙二铵阳离子转移到Mo-O^-为其可能的机理。     

Three bits eight states photochromic recording and nondestructive readout by using IR light

A photochromic polymer film containing three different diarylethene derivatives, that is, 1,2-bis(3,5-dimethyl-2-thienyl)perfluorocyclopentene (1), 1,2-bis(2,5-dimethyl-3-thienyl)perfluorocyclopentene (2), and 1,2-bis(2-methyl-5-phenyl-3-thienyl)perfluorocyclopentene (3) was prepared. Upon UV irradiation, the three derivatives changed to their closed-ring isomers having different colors, yellow, red, and blue. They showed different spectra not only in UV/Vis region but also in the IR spectral region. Upon irradiation with visible light of appropriate wavelengths, each closed-ring isomer was selectively bleached, and three bits eight states recording was performed. The eight states could be read out nondestructively by using IR light of appropriate wavenumbers.     

Cholesteric polymer guest-host mixture with circularly polarized fluorescence: two ways for phototuning of polarization and its intensity

A photosensitive fluorescent cholesteric guest-host mixture consisting of a nematic polyacrylate, a chiral, photochromic dopant sensitive to UV light, and a fluorescent dopant was prepared. The nematic polyacrylate contains 4-phenyl-4'-methoxybenzoate nematogenic side groups and photochromic 4-cyanoazobenzene side groups. The chiral-photochromic dopant formed by isosorbide and cinnamic acid is capable of E-Z photoisomerization and [2 + 2] photo-cycloaddition under light irradiation. The planarly oriented films possess a selective light reflection in the visible spectral region coinciding with the emission peak of the fluorescent dopant. The fluorescence emitted by the planarly oriented films of the mixture is strongly circularly polarized and characterized by a large value of the dis-symmetry factor. At temperatures below glass transition (T(g)) the polarized light action of an Ar(+) laser (488 nm) leads to the photo-orientation of the azobenzene fragments resulting in a strong and reversible disruption of the selective reflection and a decrease of the dis-symmetry factor of fluorescence. UV irradiation leads to E-Z isomerization and/or [2 + 2] cycloaddition of the chiral-photochromic dopant, causing an irreversible shift of the maximum of the dis-symmetry factor to a long-wavelength spectral region under subsequent annealing at temperatures higher than T(g). Such multifunctional glass-forming guest-host mixtures combining photosensitive and fluorescent properties with the unique optical properties of cholesteric liquid crystals can be considered as promising material for optical data processing technologies and photonic applications.     

双长链烷基Dawson结构钼磷酸复合薄膜的制备、结构及光致变色性质

近年来 ,无机 -有机复合材料由于其独特的结构和特殊的光、电和磁功能特性而引起科研工作者的广泛关注 [1,2 ] .杂多化合物为均一的无机多聚物 ,具有笼状结构 ,结构中均有 M3O13三金属氧簇 ,能够接受电子生成杂多蓝或杂多棕 ,加之其在水和有机溶剂中的溶解性和稳定性 ,使其在光电变色材料领域中具有潜在的应用价值 [3～ 5] .但这类化合物难于加工成实际应用的器件 ,因而限制了其进一步的应用 .利用有机组分调控的超分子自组装技术可构建光致变色同多酸或杂多酸纳米薄膜材料 ,从而为开发变色响应快、稳定性好、变色可调控的新型光电变色高密…     

Keggin结构钼磷酸/聚碳酸酯复合物的制备及光致变色性质研究

近年来，多酸－有机复合材料的研究，受到了人们的广泛关注犤１犦。杂多化合物是一类含有氧桥的多核配合物，作为高质子酸，可以提供质子与有机给体形成多酸－有机复合物，这类质子化状态的复合物具有良好的光敏性，这种特性在光化学、氧化还原催化等方面显示出重要用途。聚碳酸酯是一种综合性能优良的光学材料，研究以其为基材的杂多酸－有机复合材料的基本性能，对聚碳酸酯的改性、增进对这类复合材料的理论研究以及拓宽聚碳酸酯的应用都有重要的实际意义，迄今为止，尚未见这方面的报道。本文以Keggin结构钼磷酸（简写为PMo１２）和聚…     

Coumarinyl(thienyl)thiazoles as new fluorescent molecular photoswitches

A number of new photochromic 3-(4-phenylthiazol-5-yl)-and 3-(4-hetarylthiazol-5-yl)- coumarins has been synthesized. These compounds possess properties of molecular photo- switches providing a reversible change of the fluorescence intensity in the visible region of the spectrum upon alternating irradiation of their solutions with the visible and UV light. Irradiation with the UV light (λ < 400 nm) leads to their electrocyclization and loss of fluorescence, whereas irradiation of the cyclic form with the visible light (λ < 400 nm) returns the system to the state with the original absorption and fluorescence spectra. Switching of fluorescence is also observed in polymer matrices.     

二维相关分析光谱技术

给出推导二维相关光谱和推广至普遍意义上的数学过程,其物理含义和二维相关光谱的性质及其解释规则。以应用实例给出了该光谱技术在分析结构、相互作用等相关性方面的独特性质。还给出紫外可见二维相关光谱。     

Structure, photochromic, and electrochemical properties of dioctadecylamine/H3PMo12(O)40 Langmuir-Blodgett film

We used the Langmuir-Blodgett (LB) technique to construct a well-defined and structure-controllable photochromic material-a highly ordered multilayer film composed of dioctadecylamine and 12-molybdophosphoric acid (PMo12). We identified well-ordered lamellar structures using X-ray diffraction, polarized IR, and Raman spectra, and we determined a packing model of the two components in the LB film. We found the Keggin structure and fundamental features of the PMo12 ion to be maintained in the hybrid film. This hybrid LB film displayed photochromic properties upon UV light irradiation and we observed the following process from first-order kinetics. The photochromism exhibited the ability to switch between colorless and blue. A fading process occurred when the film was exposed to ambient air or O2 in the dark. During the color change, the packing structure of the film was well maintained. We also examined the electrochemical behavior of the hybrid LB film by cyclic voltammetry in detail and we propose different kinetic mechanisms for the film before and after irradiation.     

Characterization of A New Organic Photochromic Compound

A new organic photochromic compound, 1-phenyl-3-methyl-4-(4-fluoro)-benzal-5-pyrazolone ethanyl-thiosemicarbazone (PM4FBP-ETSC) was found to undergo photochromic reactions in the solid state. Upon irradiation with 365nm light the white powder sample turned light yellow. The photochromic properties were characterized by the time-dependent UV-vis reflective spectra. The structure of PM4FBP-ETSC was determined by single crystal X-ray diffraction.     

Synthesis, Structure and Properties of Two Photochromic Compounds Containing A Pyrazolone-ring

IntroductionThe investigation of organic photochromic materials has increased considerably in recentyears because of their potential commercial application in several areas,such as high-densityoptical storage media,optical switching,etc.[1 ,2 ] .Though numerous organic photochromicmolecular systems or photoactive devices have been explored so far,those systems classifiedaccording to the photochromic structural units mainly belong to a small number of families:fulgides,spiropyrans and spiroxazi…     

Dual-controlled dithienylmaleimide switch containing ferrocene units

A novel photochromic dithienylmaleimide (TMF) appended with two ferrocene units was synthesized from 2,3-bis(5-bromo-2-methylthiophen-3-yl)fumaronitrile. Its photochromic properties, electrochemical properties and magnetism were studied. Both fluorescence emission and redox potential were reversibly changed accompanying the open and closed-ring photoisomerization of TMF with UV/vis light irradiation and electrochemical redox. TMF may be used for fluorescent switch and electrochemical switch controlled by both light and electrochemical redox.     

钛凝胶的光致变色和电致变色特性

Titania gel is very sensitive to change of color to blue-purple by UV irradiation and to brown color under extra electric field polarzation. The UV absorption spectra of the photochromic (PC) and electrochromic(EC) titania gel are different to that of the nanocrystalline TiO_2 which changes to blue color by UV irradiation or under extra electric field polarization. The steady-state ESR measurements at room temperature indicate that ESR signals of Ti3+ appeared in PC and EC titania gel with the g values corresponding to 1.9505 and 1.9512, respectively.     

Photochromism of a novel 6pi conjugate system having a bis(2,3'-benzothienyl) unit

A novel photochromic molecule having a bis(2,3'-benzothienyl) unit has been synthesized. The derivative underwent a thermally irreversible photochromic reaction upon alternate irradiation with UV and visible light.