基于杯吡咯及其衍生物的化学传感器研究进展

杯吡咯是近年来一类新兴的超分子主体化合物,由于其独特的结构和理化性质,使得杯吡咯及其衍生物在识别金属离子、阴离子和中性小分子方面应用广泛。通过引入不同基团、改变其空腔大小得到的主体可以与不同大小、不同性质的客体分子相匹配,可作为敏感材料应用于离子选择电极、离子敏感场效应管、压电晶体、离子光导膜等多种类型的化学传感器上,对各种阴离子和中性分子的识别和检测。     

光致变色4-二乙胺基水杨醛缩对碘苯胺席夫碱的固相合成及其发光性能

以对碘苯胺和4-二乙胺基水杨醛为原料,在室温无溶剂条件下,固相反应合成了光致变色发光化合物4-二乙胺基水杨醛缩对碘苯胺席夫碱。利用核磁共振氢谱、质谱、红外光谱和元素分析对化合物结构进行了表征,通过紫外-可见吸收光谱、荧光光谱测定了它的 发 光 性 能。结 果 表 明,当 用254nm紫 外 光 和420nm可见光照射时,该化合物表现出良好的可逆光致变色性能;在不同极性溶剂条件下表现出良好的溶剂变色性能,同时表现出不同波长的荧光发射性能,在吡啶做溶剂条件下表现出较大的Stoke位移。另外,该化合物在质子H+和碱OH-作用下,表现出良好的发光开关特性。该多功能席夫碱化合物在信息存储、分子开关和非线性光学材料领域里具有潜在的应用价值。     

螺噁嗪的光开关特性对聚合物电致发光性能的影响

基于螺噁嗪化合物光致变色过程中的光开关特性,将光致变色螺吲哚菲并噁嗪化合物(SO)掺杂到主体电致发光材料聚[2-甲氧基-5-(2’-乙基己氧基)-对亚苯基亚乙烯](MEH-PPV)中,制成结构为ITO/PEDOT:PSS/MEH-PPV:SO/LiF/Al的发光二极管,初步探讨了光照对发光二极管性质的影响。通过光致变色反应,SO的开环成色体可充当注入载流子的陷阱而影响二极管的性质。所以,紫外光照前后MEH-PPV发光二极管的电致发光性质,包括电流、亮度、发光强度等性质,通过螺噁嗪化合物分子的光开关特性而变化。     

光致变色二芳烯材料的光子型光信息存储

本文合成了八种光致变色二芳烯化合物,研究了它们的光致变色性质,并综述了它们在光子型光信息存储技术中的应用.在光辐照下,这些化合物在溶液和PMMA膜中均具有良好的光致变色特性.使用这些化合物作为光存储介质,成功进行了系列高密度光子型光信息存储实验,包括全息光存储、双光子光存储和多波长光存储.结果表明:二芳烯材料是光子型全息、双光子和多波长光存储技术中可采用的最理想的存储介质之一.     

二芳基乙烯光致变色配合物的研究进展

二芳基乙烯化合物是最有可能实用化的有机光致变色化合物.结合自己的研究方向,从溶液相和晶体相2个方面评述了二芳基乙烯配合物在光致变色性能、无损读取、分子识别/捕获等方面的研究进展.研究表明,在大多数情况下,金属离子参与配位不会阻止配合物的光致变色反应.通过金属离子与二芳基乙烯配体的合理自组装,可以调控配合物的光物理和光化学性质.     

单根Ag(TCNQ)微/纳米结构的光致变色特性研究

利用溶液化学反应法制备了准一维微/纳米结构的金属有机配合物Ag(TCNQ);X射线衍射(XRD)表明所制备的Ag(TCNQ)为晶态结构;扫描电子显微镜(SEM)的观察表明Ag(TCNQ)为准一维的微/纳米管或线.首先在自行研制的材料光学性能测试系统上对单根Ag(TCNQ)的光致变色特性进行测试,激光照射后颜色由深蓝变黄;然后利用显微Raman光谱仪对其光致变色机理进行了研究,激光照射后的光谱图中出现了明显的TCNQ分子的特征中性峰.如照射时间较长,超过30s,则TCNQ分子特征峰又消失.因此Raman测试结果证明单根Ag(TCNQ)微/纳米结构具有明显可逆的光致变色特性.     

基于酞菁光控自组装的超分子三阶非线性光开关材料

酞菁的三阶非线性光学性能不仅取决于其分子结构，而且与酞菁分子在空间的排列密切相关。因此，控制酞菁化合物在空间的排列状态，就有望在超分子的层次控制酞菁的三阶非线性光学性能。我们设计了三类含有光致变色单元修饰的酞菁化合物。利用紫外光和可见交替照射下光致变色单元光异构过程中空间结构和电子结构的改变，实现了对酞菁自组装行为的有效光控。我们用Z-扫描的方法考察了光照前后这些酞菁光控自组装体系三阶非线性光学性能的改变。发现：这些材料不仅开关效应显著，且在“开”和“关”的状态下，都具有大的二阶分子超极化率（〉10^-30esu），在未来光电子和光子技术领域具有潜在的应用价值。     

有机光致变色化合物及其应用

综述了目前研究较多的几种有机光致变色化合物的光致变色反应、光变性能和研究进展,介绍了目前广受关注的双光子光致变色反应过程,以及有机光致变色化合物的应用,并展望了其发展方向.     

真空蒸发沉积18烷基取代螺吡喃薄膜的光致变色及光电子谱研究

利用真空蒸发的方法在玻璃载片上沉积了 18烷基取代螺吡喃薄膜 ,并利用光吸收谱和光电子谱研究了薄膜的光致变色特性及变色前后分子结构的变化情况。实验结果发现 ,真空蒸发沉积的 18烷基取代螺吡喃薄膜具有良好的光致变色性能 ,在紫外光的照射下可以发生明显的光致变色反映。光电子谱分析 :经紫外线照射后 ,N1s、O1s光电子峰发生明显的变化 ,说明经紫外线照射后分子结构发生了变化 ,导致分子内部电荷的重新分布。另外紫外线照射后氧含量增加 ,这是因为紫外线照射后薄膜表面对水汽的吸附能力增加所致     

哌嗪改性4,4’—二氨基二苯甲烷系光发色感光性树脂的研究

重氮化合物等光发色材料,螺吡喃等光致变色材料,在紫外光照射下能够发色或变色,作为非银盐感光材料已经获得应用。芳香胺和四溴化碳等有机多卤化物的发色机制,1961年 R·H·Sprague 提出了生成三苯甲烷染料的机制。七十年代有人合成了二苯甲烷类发色化合物。星野昭一郎根据 Sprague 机制,设计了光发色固化型金属凸版用抗蚀剂曾经商品化。余尚先一山冈     

Photoswitching and Thermoresponsive Properties of Conjugated Multi‐chromophore Nanostructured Materials

Conjugated multi‐chromophore organic nanostructured materials have recently emerged as a new class of functional materials for developing efficient light‐harvesting, photosensitization, photocatalysis, and sensor devices because of their unique photophysical and photochemical properties. Here, we demonstrate the formation of various nanostructures (fibers and flakes) related to the molecular arrangement (H‐aggregation) of quaterthiophene (QTH) molecules and their influence on the photophysical properties. XRD studies confirm that the fiber structure consists of >95% crystalline material, whereas the flake structure is almost completely amorphous and the microstrain in flake‐shaped QTH is significantly higher than that of QTH in solution. The influence of the aggregation of the QTH molecules on their photoswitching and thermoresponsive photoluminescence properties is revealed. Time‐resolved anisotropic studies further unveil the relaxation dynamics and restricted chromophore properties of the self‐assembled nano/microstructured morphologies. Further investigations should pave the way for the future development of organic electronics, photovoltaics, and light‐harvesting systems based on π‐conjugated multi‐chromophore organic nanostructured materials.     

Incorporation of Ru(II) Polypyridyl Complexes into Nanomaterials for Cancer Therapy and Diagnosis

Ru(II) polypyridyl complexes are compounds of great interest in cancer therapy due to their unique photophysical, photochemical, and biological properties. For effective treatment, they must be able to penetrate tumor cells effectively and selectively. The development of nanoscale carriers capable of delivering Ru(II) polypyridyl complexes has the potential to passively or selectively enhance their cellular uptake in tumor cells. Many different strategies have been explored to incorporate Ru(II) polypyridyl complexes into a variety of nanosized constructs, ranging from organic to inorganic materials. Herein, recent developments in nanomaterials loaded with Ru(II) polypyridyl complexes are highlighted. Their rational design, preparation, and physicochemical properties are described, and their potential applications in cancer therapy are eventually discussed.     

Fabrication of Metal Molybdate Micro/Nanomaterials for Electrochemical Energy Storage

Currently, metal molybdates compounds can be prepared by several methods and are considered as prospective electrode materials in many fields because the metal ions possess the ability to exist in several oxidation states. These multiple oxidation states contribute to prolonging the discharge time, improving the energy density, and increasing the cycling stability. The high electrochemical performance of metal molybdates as electrochemical energy storage devices are discussed in this review. According to recent publications and research progress on relevant materials, the investigation of metal molybdate compounds are discussed via three main aspects: synthetic methods, material properties and measured electrochemical performance of these compounds as electrode materials. The recent progress in general metal molybdate nanomaterials for LIBs and supercapacitors are carefully presented here.     

Ion-induced manipulation of photochemical pathways in crown ether compounds based on fluorinated oligophenylenevinylenes: the border between ultrafast photoswitches and photoproduced nanomaterials

The photochemical and photophysical properties of the crown ethers trans,trans-1,4-bis[2-(3',4'-benzo 15-crown 5)ethenyl]-2,3,5,6-tetrafluorobenzene (1) and trans,trans-1,4-bis[2-(3',4'-benzo 18-crown 6) ethenyl]-2,3,5,6-tetrafluorobenzene (2) were investigated in the absence and presence of groups I and II metal ions. The photophysical methods used include steady state flurescence, uv spectroscopy, and ultrafast transient absorption spectroscopy. Both compounds showed solvatochromic behavior, due to intramolecular charge transfer state formation, and efficient fluorescence in polar solvents. Photophysical behavior was dependent on the metal ion. The addition of metal ions that completely fit into the crown ether cavity resulted in significant blue shifts in the fluorescence emission spectra (chemosensing properties). Partially fitting ions changed the fluorescence spectra slightly. Transient absorption measurements revealed fast and slow decay components with time constants of 10-20 and 500-600 ps for all fitting ions, respectively. The latter is assigned to a trans-cis photoisomerization process, which decreased in efficiency in the presence of partially fitting ions, i.e., increasing ion size. Steady state irradiation showed clear evidence of a change in the absorption spectra. Trans-cis photoisomerization and [2 + 2] photocycloaddition were found to compete with fluorescence. The ions Li+, Na+, and Ca2+, which fit into the cavity, direct the photoisomerization. Larger ions (K+, Rb+, Sr2+ and Ba2+) that partially fit the cavity cause photocycloaddition. Quantum yields of the photoreaction are between 0.1 and 0.3. Analysis of the photo-product obtained for the 1-Sr2+ system revealed a compound with a molecular weight of nanosize dimension, which was equivalent to seven mass units of 1. The higher molecular weight product was formed due to alternately stacked supramolecular assemblies.     

On‐Demand Control of the Photochromic Properties of Naphthopyrans

Photofunctional compounds have emerged as critically important materials for both fundamental studies and industrial applications. Control of the thermal decoloration speed to within several seconds while sustaining satisfactory photochromic colorability is an important challenge for the application of such materials to photochromic lenses and smart windows. Photochromic naphthopyran derivatives are utilized for photochromic lenses because of their high durability and easily controllable colorability. However, the residual color imparted by the long‐lived transient species upon ceasing light irradiation remains a hindrance to practical applications. In this study, a strategy is demonstrated for on‐demand control of the thermal decoloration speed of the transient colored species of naphthopyran derivatives. The increase in the ring‐size of the alkylenedioxy moiety on the naphthopyrans accelerates the thermal back‐reaction independently of the maximum‐absorption wavelength of the colored isomer, leading to the realization of yellow‐, red‐, and blue‐photochromic naphthopyrans with similar thermal fading speeds. This novel molecular design provides a strategy for the future development of advanced photoresponsive materials.     

Carbon and Nitrogen Based Nanosheets as Fluorescent Probes with Tunable Emission

2D carbon and nitrogen based semiconductors (CN) have attracted widespread attention for their possible use as low‐cost and environmentally friendly materials for various applications. However, their limited solution‐dispersibility and the difficulty in preparing exfoliated sheets with tunable photophysical properties restrain their exploitation in imaging‐related applications. Here, the synthesis of carbon and nitrogen organic scaffolds with highly tunable optical properties, excellent dispersion in water and DMSO, and good bioimaging properties is reported. Tailored photophysical and chemical properties are acquired by the synthesis of new starting monomers containing different substituent chemical groups with varying electronic properties. Upon monomer condensation at moderate temperature, 350 °C, the starting chemical groups are fully preserved in the final CN. The low condensation temperature and the effective molecular‐level modification of the CN scaffold lead to well‐dispersed photoluminescent CN thin sheets with a wide range of emission wavelengths. The good bioimaging properties and the tunable fluorescence properties are exemplified by in situ visualization of giant unilamellar vesicles in a buffered aqueous solution as a model system. This approach opens the possibility for the design of tailor‐made CN materials with tunable photophysical and chemical properties toward their exploitation in various fields, such as photocatalysis, bioimaging, and sensing.     

光致变色材料的研究与应用

变色材料在变色眼镜、光学信息存储、光分子开关等方面具有广泛的应用.主要分析了螺吡喃、俘精酸酐、二芳基乙烯以及二氧化钛、卤化银等有机和无机光致变色材料的研究现状及其变色机理,最后介绍了光致变色材料在国防以及信息存储材料等方面的应用前景.     

Synergistic Intra‐ and Intermolecular Noncovalent Interactions for Ultralong Organic Phosphorescence

Metal‐free ultralong organic phosphorescence (UOP) materials have attracted significant attention owing to their anomalous photophysical properties and potential applications in various fields. Here, three pyrimidine‐based organic luminogens, 9‐(pyrimidin‐2‐yl)‐9H‐carbazole, 9‐(4,6‐dimethylpyrimidin‐2‐yl)‐9H‐carbazole, and 9‐(5‐bromopyrimidin‐2‐yl)‐9H‐carbazole are designed and synthesized, which show efficient yellow UOP with the longest lifetimes up to 1.37 s and the highest absolute phosphorescence quantum yields up to 23.6% under ambient conditions. Theoretical calculations, crystal structures, and photophysical properties of these compounds reveal that intramolecular hydrogen bonding, intermolecular π–π interactions, and intermolecular electronic coupling are responsible for forming dimers and generating highly efficient UOP. Their efficacy as solid materials for data encryption is demonstrated.