激发态分子内质子转移荧光探针的研究进展

综述了基于激发态分子内质子转移(ESIPT)荧光探针的相关研究,并对ESIPT机理和ESIPT荧光团的2-(2'-羟苯基)苯并杂环类(咪唑、(噁)唑、噻唑)及其衍生物等的主要结构进行了系统介绍.重点介绍了双发光机制荧光探针在检测方面的应用进展.     

新罗丹明衍生物的合成及其分子内能量传递

通过乙基桥把接上供电子基团哌嗪的1,8-萘酰亚胺与罗丹明B相连,合成了新的罗丹明衍生物,研究了基态下新罗丹明衍生物各发色团之间的相互作用,以及新罗丹明衍生物荧光发射光谱及分子内能量传递.结果表明,由于合成的新罗丹明衍生物发色团之间的给电子作用,导致对比罗丹明B及4-哌嗪-1,8-萘酰乙醇亚胺的最大吸收峰红移,在激发态下4-哌嗪-1,8-萘酰乙醇亚胺-罗丹明B二元体系发生了分子内能量传递,当以400、450、480 nm激发时,随激发波长向长波方向靠近,所吸收的能量传递给了长波色素分子团罗丹明趋势变大.     

乙酰基二茂铁缩氨脲的合成及其电化学性质

以二茂铁为原料通过两步反应合成了标题化合物,其结构通过IR、1HNMR和元素分析予以确证。采用循环伏安法测定了该化合物在无水乙腈溶液中的电化学性能。实验结果表明,在扫描范围(-0.1～0.83 V)内,标题化合物出现了一对氧化还原峰;当扫描速度在100～500 mV/s范围时,其半波电位(E1/2)为0.476～0.466 V;峰电流比(Ipa/Ipc)为1.387～1.269,并且峰电流(Ip)与扫描速度平方根(ν1/2)呈良好的线性关系。     

2,1,3-Benzoxadiazole and 2,1,3-benzothiadiazole-based fluorescent compounds: Synthesis,characterization and photophysical/electrochemical properties

Six new fluorescent compounds derived from 2,1,3-benzoxadiazole and 2,1,3-benzothiadiazole heterocycles with varying numbers of alkoxy chains were successfully synthesized. Sonogashira cross-coupling was used as the key synthetic step to link the central and terminal aromatic units through an acetylenic linker unit which ensures molecular planarity and extension of the conjugation. All of the synthesized compounds showed UV–vis absorption in the 426–437 nm range with reasonably high molar extinction coefficients. All six compounds emit in the green region of the visible spectrum with reasonably large Stokes shifts (95–107 nm) and medium emission efficiencies (Φ_f = 0.27–0.32). Electrochemical studies showed that the compounds have closely spaced HOMO and LUMO energy levels and that they may present good electron transporting properties.     

Synthesis and electrochemical properties of phloroglucin‐based ferrocenyl compounds and their application in anion recognition

Phloroglucin‐based ferrocenyl compounds, including hyperbranched phloroglucin‐based ferrocenyl polymer and phloroglucin‐based ferrocenyl dendrimer (Generation0), were prepared by a convenient approach. Cyclic voltammograms were used to investigate their electrochemical properties, and we found that the scanning rate and solvent had remarkable effects on electrochemical behavior of the compounds. These compounds showed electrochemical responses to the anions, and a selective recognition for H₂PO over other anions was observed. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci, 2008     

Synthesis, characterization and electrochemical properties of polybiselenophene

A novel electrically conducting polymer consisting of selenophene moiety, poly(biselenophene) (PBSE) was generated by chemical and electrochemical polymerization. This polymer gave lower bandgap energy (1.9 eV) than pristine polyselenophene (2.0 eV). The electrochemical and optical properties of PBSE was investigated by UV-Vis near infrared spectroscopy and electrochemistry. In situ electrochemical doping studies of PBSE showed the formation of polaron states at 1.4 and 0.8 eV. Through cyclic voltammetry, the polymer oxidation potential (E_pa) and reduction potential (E_pc) for p-doping process for PBSE were observed at 0.93 and 0.86 V, respectively, at a scan rate of 20 mV s⁻¹. Upon chemical doping using chemical reagents such as iodine and ferric chloride, a maximum conductivity of 0.1 S cm⁻¹ was achieved.     

Synthesis and electrochemical properties of new viologen polymers

New polymeric viologens containing tetra-, tri-, or diethylglycol links as 1,1-substituents has been synthesized by the reaction of tosylated ethylglycols with dipyridine in N, N-dimethylformamide (DMF). Thin films of insoluble hexafluorophosphate salts of these polyviologens were examined using electrochemical technique, electrochemical quartz crystal microbalance (EQMB), and atomic force microscopy (AFM). The cyclovoltammetric results show that the composition of the polyviologen determines the kinetics of the redox reactions and the mode of the charge transport through the film. The charge compensation during the reduction process is accomplished by cation insertion, and vice versa during oxidation. However, the EQMB data indicate that some anion insertion during oxidation also takes place. Water movement during the redox processes was observed.     

LiFePO4的制备及其电化学性能

本文采用溶胶一凝胶法,以柠檬酸、EDTA和草酸为络合剂制备了LiFePO4,经XRD表征证明所得产品为橄榄石型磷酸铁锂。以放电曲线、循环寿命和电化学阻抗谱研究了LiFePO4的电化学性能,发现以柠檬酸为络合剂制备的LiFePO4的电化学性能最好。     

MnO2纳米空心球的制备及其电化学性能

采用水热法通过添加Ce离子制备了MnO₂纳米空心球电极材料。Ce离子对MnO₂的形貌和结晶程度有很大的影响,添加Ce离子后生成由纳米棒组成的中空球,中空球比表面积(BET)达到315.2 m²·g^-1。MnO₂电极电化学测试结果表明:当铈锰摩尔比为0.2时电极材料具有较好的电化学性能,其比电容达到178.6 F·g^-1,与未加Ce离子相比其比电容提高了2.6倍,而且经过1000次循环稳定性测试后比电容仍保留了90.5%。这些结果表明添加Ce离子有利于形成中空结构,并提高了MnO₂电极的比电容。     

利用相转移催化法合成Reissert化合物

喹啉、异喹啉等杂环化合物与酰卤、氰化钠(或钾)生成的加成产物为Reissert化合物,例如N-苯甲酰基-1,2-二氢喹啉腈(1)、N-苯甲酰基-1,2-二氢异喹啉腈(2)。由于它们的氰基可转换成羧酸或醛,又可经负碳离子在杂环上引入侧链,因此Reissert化合物是重要的合成中间体[1]。     

Synthesis and properties of compounds related to stilbazole

We report attempts to create conjugated polymers consisting of alternating phenylene and heterocyclic rings separated by double bonds by means of condensations between terephthalaldehyde and dimethyl nitrogen bases. Because the products precipitated during their formation even at 180°C in N-methyl-2-pyrrolidinone (NMP), only oligomers of up to ca. 30 rings (DP = 15) could be obtained; most of the adequately soluble products had DP between 4 and 8, and from these oligomers films on glass or quartz could be made. When the films were exposed to I₂, NO₂, or SbF₅, most of them, initially very good insulators, showed an increase in electrical conductivity of up to 6 powers of 10; but the rapid reversal of this change when the reagent evaporated and the lack of any clear changes in the UV-vis spectrum of the films showed that most likely true “doping” had not occurred. Extensive syntheses with a variety of quaternised bases also failed to yield oligomers oxidisable by electron-acceptors. For reference purposes, especially for their spectra, a large number of pure “model” compounds of the distyrylpyridine and distyrylpyrazine type, and quaternised analogues of the former, were synthesised, many of them new compounds. These were also used as calibrants for a GPC column operating with NMP solutions. Several improvements were made in the synthetic techniques.     

Synthesis,characterization and electrochemical properties of functionalized graphene oxide

Graphene oxide (GO) was functionalized by a simple reaction of its carboxylic acid groups with a silanized-metalloid polymer, which gave the resulting hybrid GO the property of efficient dispersion in a variety of solvents. Spectroscopic investigations show that the covalent attachment is effectively accomplished through an amidation process. The combination of a metalloid polymer and GO is unique and the composite material exhibits interesting features not seen in the individual structures. The electrochemical properties of this metalloid–polymer-GO were demonstrated by immobilizing the sample on a conventional gold-printed circuit board (Au-PCB) electrode. Functionalized GO showed a perfect scaling of steady-state currents with correlation coefficients of 0.9600 (I_pc) and 0.9552 (I_pa), indicating the promise of this new GO hybrid as a transducer material for many sensing applications.     

Synthesis, photophysical and electrochemical properties of 1-aminoperylene bisimides

1-Aminoperylene bisimides (1a-1c) were synthesized under mild condition in high yields, and were characterized by FT-IR, ¹H NMR, UV-Vis, HRMS spectra, cyclic voltammetry, differential scanning calorimetry, and thermogravimetric analyses. These compounds are stable up to 310 °C according to thermogravimetric analyses. They undergo two quasi-reversible one-electron oxidations and two quasi-reversible one-electron reductions in dichloromethane at modest potentials. Their spectroscopic properties in various conditions and complementary density functional theory (DFT) calculations are reported.     

高性能水合钒酸锌纳米棒的合成与电化学性能研究

本文报道了一种以Zn（NO₃）₂与偏钒酸铵为原料,采用水热法合成的水合钒酸锌(Zn₃V₂O₇（OH）₂·2H₂O)材料。XRD结果表明,该材料具有高纯的晶体结构;扫描电子显微镜表明,该材料是由一维纳米棒构成。而且该材料作为可充锌离子电池正极,在电化学测试中表现出优异的性能。因此,本研究工作不仅提供了一种新型的低维纳米材料合成技术,而且为高性能可充锌离子电池的发展提供了帮助。     

Synthesis and electrochemical properties of lithium-electroactive surface-stabilized silicon quantum dots

Highly lithium-electroactive Si quantum dots (n-Si), coated with an amorphous carbon layer, were prepared by of butyl-capped Si annealing at 700 or 900 °C. The ordering of the carbon layer structure increased with increasing annealing temperature while the thickness decreased to 1 from 2 nm due to the increased ordering of carbon. n-Si, annealed at 900 °C, had the same particle size (5 nm) as n-Si annealed at 700 °C. In contrast to Si nanocrystals with an average particle size of 30 nm that had a first charge capacity of 225 mAh/g with a very small coulombic efficiency of 4%, n-Si that annealed at 900 °C possessed a first charge capacity of 1257 mAh/g with a significantly enhanced coulombic efficiency of 71%. This improvement was due to the uniform distribution of n-Si with a carbon layer that prohibited n-Si aggregation during cycling.     

Synthesis and electrochemical properties of TiO2/nanodiamond nanocomposite

Undoped nanodiamond (ND) powders were coated with TiO₂ through two steps: firstly Ti lay was deposited by cycled vacuum-feeding chemical vapour deposition from gaseous TiCl₄/H₂, and secondly an oxidation treatment was carried out in air. The structure and the morphology of the TiO₂/ND composite were characterized by Raman spectrum and transmission electron microscopy. The electrochemical properties of the TiO₂/ND powder electrode in a solution containing [Fe(CN)₆]^3?/4? or NO₂^? were investigated. The results showed that a continuous coating consisting of Ti nanoparticles covered on ND particle after the deposition. The following oxidation at 500 °C resulted in the formation of anatase phase TiO₂ nanoparticles of about 10 nm. The electrochemical results confirmed that the TiO₂/ND powder electrode exhibited higher electrochemical activity than the pristine ND electrode, especially higher catalytic ability toward the oxidation of nitrite anions. Moreover, the TiO₂/ND powder electrode presented fast response towards nitrite oxidation with a detection limit of 0.55 µM and a linear range of 0.05 to 1.0 mM.     

相转移催化合成哒嗪酮鼠李糖糖苷类化合物

首次使用取代哒嗪酮和溴代鼠李糖在相转移催化剂作用下合成了4,5-2H-1-取代-6-羰基哒嗪酮-3-三乙酰鼠李糖苷类化合物,达到反应时间缩短,收率提高的目的。结构经IR与1HNMR表征。     

Synthesis and electrochemical properties of mixed ionic and electronic modified polycarbazole

A carbazole N-substituted by an oxyethylene group was polymerized using oxidative electro-polymerization. Due to the hydrophilic properties of the oligooxyethylene substituent, this monomer can be solubilized and electropolymerized in aqueous electrolyte solution. An acidic medium is particularly appropriate in order to decrease the oxidative potential and to obtain films mainly composed of short oligomers as revealed by GPC analysis. By comparison, the chemical polymerization of the corresponding 3,6 dibromo derivative leads to oligomers with well-defined structure and leads to the obtention of longer macromolecular chains. Electrochromic properties of these materials have been studied and a transition from colorless to deep green has been observed during the oxidation. More particularly interesting are the stability of such materials during polarization and the kinetics of diffusion of the counter ion in the film. In acidic medium 1.25 mol l⁻¹ HClO₄, 95% of the charge density was maintained after polarization for 7000 cycles which shows the good electrochemical stability of this material compared with other polycarbazoles. Diffusion coefficient have been evaluated in aqueous media about D_ClO4⁻=10⁻¹¹ cm² s⁻¹. Moreover, films are electroactive in oxyethylene based electrolytes. Then, they are probably well-compatible with hydrophilic poly(oxyethylene) solid electrolytes such that all-polymer devices may be prepared.     

纳米四氧化三钴的合成表征及各自在电化学性能的研究

以六水合硝酸钴(Ⅱ)、六水合氯化钴(Ⅱ)为原料制备纳米级别的棒状四氧化三钴、管状四氧化三钴及片状四氧化三钴。利用XRD对制备的产物与原料、中间体进行对比研究,利用SEM观察产物形貌,并利用电化学工作站对不同产物的电化学性能进行研究。经研究发现,在以2 mol/L KOH溶液为电解液的条件下,四氧化三钴纳米棒的电化学性能最为优异。     

双羟基吡喃酮化合物的合成及清除自由基性能

以麦芽酚或乙基麦芽酚为起始原料，经乙酰化、钯碳氢化、羰基α位乙酰氧化和脱乙酰基等4步反应，合成了两种双羟基吡喃酮化合物。利用核磁共振氢谱、碳谱和高分辨质谱对每一步反应产物进了结构表征，优化了合成反应工艺，并通过清除自由基反应对化合物的抗氧化活性进行了测试。结果表明，双羟基吡喃酮化合物对ABTS+?、DPPH?和galvinoxyl?三种自由基清除率分别达到88.9%、83.8%和68.4%，明显高于维生素E和2,6-二叔丁基对甲酚的自由基清除率，表现出优异的抗氧化活性。构效关系研究表明，在吡喃酮结构中引入羟基或增强侧链取代基的给电子能力均能提高化合物清除自由基的能力，为新型抗氧化剂的合成开发提供了参考。