两个新的苯并噻唑衍生物的合成与光物理性质

以苯并噻唑、苯乙酰基和吡啶阳离子为电子受体，二乙烯基苯为共轭桥，合成了两个新的A-π-A’型苯并噻唑衍生物：4-（2-苯并噻唑）-乙烯基查尔酮（1）和4-{4-[2-（苯并噻唑）乙烯基]苯乙烯基}-N-甲基吡啶碘盐（2）．研究了它们在溶液和固体基质中的光物理性质．研究发现：染料2由于具有较强的极性和较好的平面性，从而具有较长的吸收、发射峰和较强的荧光发射．有机染料在聚甲基丙烯酸甲酯／溶胶-凝胶复合玻璃中的发光行为与聚甲基丙烯酸甲酯和溶胶-凝胶玻璃二者的基质性质有关，同时由于固体基质中分子发生聚集的可能性降低，荧光强度相对于同浓度溶液增强，稳定性提高．     

含咔唑基团芘类荧光材料的合成与发光性质

以1-溴芘、1,6-二溴芘和9-对乙炔苯基咔唑为原料,通过Sonogashira偶联反应合成了1-[4-(9-咔唑)苯乙炔基]芘和1,6-二[4-(9-咔唑)苯乙炔基]芘两种荧光分子。经熔点、核磁共振氢谱以及元素分析等结构表征,对中间体和目标产物的紫外-可见吸收、荧光发射以及结构与性质之间的构效关系进行了研究。通过结构修饰,可有效调节此类分子的吸收及发射性质。当芘单元作为中心电子受体,以4-苯乙炔基为桥连基,引入咔唑基团作为电子给体时,其分子共轭程度、结构刚性和分子内电荷转移能力显著提高。相对于D-π-A结构的单取代化合物,双取代D-π-A-π-D结构分子的最大发射峰由422 nm红移至446 nm,荧光量子效率由0.64提升至1.08。该类化合物可作为高效的蓝光荧光材料,应用于有机光致/电致发光材料以及有机发光二极管等领域。     

1，4－双（4’－N，N－二甲基氨基苯乙烯基）萘的合成及荧光性质

利用Wittig反应合成了一个以萘为π-Center的对称型“D-π-D”有机绿色发光化合物1，4-双(4'-N，N-二甲基氨基苯乙烯基)萘(BDASN)，并测试了其在不同环境中的光谱性质．在378nm激发波长的激发下，BDASN显示出很强的荧光发射峰，峰位在521nm(CH2Cl2)．随着溶剂极性增大，最大发射波长红移且荧光强度降低，与“D-π-A”分子具有相似的分子内电荷转移(TICT)行为．在β-环糊精(β-CD)中BDASN的绿色发光带被猝灭，同时在450nm附近蓝发光带的荧光强度骤增．     

荧光标记AA-AMPS共聚物的性能研究

对用4-(N'-甲基-1-哌嗪基)-N-丁基-1,8-萘二甲酰烯丙基氯季铵盐(FC)作荧光标记的丙烯酸(AA)/2-丙烯酰胺基-2-甲基丙磺酸(AMPS)聚合物(FC-POCA)进行性能评价,研究了pH、氧化剂、常规阻垢剂对荧光强度的影响.实验结果表明:在pH为8-10、常规阻垢剂和氧化剂存在下,聚合物的荧光强度稳定,荧光强度与浓度呈良好的线性关系.聚合物具有良好的阻垢性能.     

含萘荧光聚合物海水阻垢剂的合成及其阻垢性能

合成了水溶性含萘荧光单体2-(甲基丙烯酰氧)-N,N-二甲基-N-(1-萘甲基)乙基氯化铵,并将此荧光单体与丙烯酸进行共聚得到含萘荧光聚合物,考察了其在海水中的荧光特性和阻垢性能.结果表明.该聚合物的荧光强度与其质量浓度在海水中呈良好的线性关系,具有较好的阻CaCO3垢性能,表明这是一类潜在的可用于海水循环冷却的示踪型阻垢分散剂.     

3-溴-9-(2-萘基)-9H-咔唑的合成

以咔唑为原料,通过乌尔曼反应合成了N-(2-萘基)咔唑,然后经溴化反应,合成空穴传输材料中间体3-溴-9-(2-萘基)-9H-咔唑,并对溴化条件进行了初步探索。结果表明,溴化的最佳反应条件为:25℃,24 h,n[N-(2-萘基)咔唑]∶n(四丁基三溴化铵)=1∶1.05,二氯乙烷100 mL。其结构经元素分析、1HNMR和MS确认。     

新型多环thienoacene基共轭聚合物太阳能电池研究进展

近年来,用于体异质结有机光伏器件的聚合物给体材料的发展受到了广泛关注,多环thienoacene与一些性能优良的电子受体单元构建的电子给体-受体型窄带隙共轭聚合物,具有良好的π-π堆积性能和高电荷迁移率,是当前高效聚合物太阳能电池的研究热点。本文概述了几类thienoacene基共轭聚合物作为电子给体与电子受体PCBM下的光伏器件的研究进展及取得的成就,同时对其存在问题与拟解决途径做了简要阐述。     

含咔唑基聚合物的合成、发光性能及应用

采用封管聚合法合成了3种含咔唑基聚合物——聚乙烯基咔唑(PVK)、聚2-(9-咔唑基)乙基甲基丙烯酸酯(PCEM)和聚N-〔3-(9-乙基咔唑基)〕甲基丙烯酰胺(PECMA),考察了其紫外光谱和荧光光谱,探讨了取代基对咔唑基团发光性能的影响。结果表明,单体CEM和ECMA表现出明显的结构自猝灭效应(SSQE),而相应的聚合物未见SSQE。单体乙烯基咔唑(NVK)、CEM的荧光最大发射波长分别为440、435 nm,相对于咔唑(418nm)有明显的红移,ECMA则蓝移(410 nm),而相应的聚合物红移或蓝移都不明显。将聚合物作为空穴传输材料,通过共聚引入8-羟基喹啉铝高分子后,8-羟基喹啉铝高分子发光材料的电致发光起亮电压由14 V下降至9V,发光效率提高了3~4倍。     

掺杂聚乙烯基咔唑的螺噁嗪光致变色的性能

将PVK(聚乙烯基咔唑)以不同的比例掺杂至螺噁嗪光致变色化合物的体系中,通过对螺噁嗪开环体紫外-可见光谱和聚乙基咔唑荧光光谱的分析可以得出,掺杂体系中聚乙烯基咔唑中的电子空穴可容纳螺噁嗪光致变色过程中迁移的电子,从而提高了螺噁嗪开环的效率。     

含咔唑基团芘类荧光材料的合成与发光性质

以1-溴芘、1,6-二溴芘和9-对乙炔苯基咔唑为原料,通过Sonogashira偶联反应合成了1-（4-（9-咔唑）苯乙炔基）芘和1,6-二（4-（9-咔唑）苯乙炔基）芘两种荧光分子。经熔点、核磁共振氢谱以及元素分析等结构表征,对中间体和目标产物的紫外-可见吸收、荧光发射以及结构与性质之间的构效关系进行了研究。通过结构修饰,可有效调节此类分子的吸收及发射性质。当芘单元作为中心电子受体,以4-苯乙炔基为桥连基,引入咔唑基团作为电子给体时,其分子共轭程度、结构刚性和分子内电荷转移能力显著提高。相对于D-π-A结构的单取代化合物,双取代D-π-A-π-D结构分子的最大发射峰由422 nm红移至446 nm,荧光量子效率由0.64提升至1.08。该类化合物可作为高效的蓝光荧光材料,应用于有机光致/电致发光材料以及有机发光二极管等领域。     

Triphenylamine-based organic dyes containing a 1,2,3-triazole bridge for dye-sensitized solar cells via a ‘Click’ reaction

Three new organic dyes with one, two and three branched D-π-A structures derived from an electron donating triphenylamine core and connected by 1,2,3-triazole group to an electron deficient cyanoacrylate system have been conveniently synthesized via a ‘Click’ reaction. It was found that all three dyes show UV-vis absorptions in the 300-500 nm range with high molar extinction coefficients. A red-shift of UV-vis absorption band was observed in the solid thin film compared with the dioxane solution. Dye-sensitized solar cell devices based on the dyes were fabricated and tested. The one branched triphenylamine-based dye exhibits the highest energy conversion efficiency. Increase of the branched D-π-A structure around the triphenylamine core results in the decrease of energy conversion efficiency of the dyes, which can be attributed to less attachment of the dyes onto TiO₂ photoanode with the enlarged molecular size of the corresponding multibranched structure.     

Optical properties of donor-π-(acceptor)n merocyanine dyes with dicyanovinylindane as acceptor group and triphenylamine as donor unit

Donor-π–(Acceptor)_n (D-π-A) type dyes were synthesized and their absorption and emission spectra investigated in different solvents. Strong acceptor units imparted large red-shifts in absorption; the twisting of the dye's structure imposed by an acceptor unit quenched fluorescence. Electron delocalization before and after excitation was observed according to molecular orbital calculations. The results indicated potential use of the dyes as electro-optical materials.     

Processable electrochromic and fluorescent polymers based on N-substituted thienylpyrrole

A new series of processable conducting polymers based on thienylpyrrole was synthesized by electrochemical polymerization of 1-(1-naphthyl)-2,5-di(thiophen-2-yl)-1H-pyrrole, 1-(2-naphthyl)-2,5-di(thiophen-2-yl)-1H-pyrrole, 1-(9H-fluoren-2-yl)-2,5-di(thiophen-2-yl)-1H-pyrrole and 1-(benzo-15-crown-5)-2,5-di(thiophen-2-yl)-1H-pyrrole. The corresponding polymers have very well-defined and reversible redox processes in both organic and aqueous solutions. Furthermore, they exhibit multielectrochromic behavior: yellow in the neutral state, green and blue in the intermediate state and violet in the oxidized state. The polymer products are soluble in organic solvents and all of them are fluorescent.     

Studies on Aminoanthraquinone Compounds

A study has been made of the action of near-ultraviolet and visible radiation on anaerobic solutions of 1- and 2-piperidinoanthraquin-ones in different organic solvents, and on polymer films dyed with these dyes. In the absence of oxygen, 1-piperidinoanthraquinone is reduced to the anthrahydroquinone on irradiation in solution and on nylon films. Under similar conditions, 2-piperidinoanthra-quinone is reduced to the anthrone in organic solvents, but the photochemical changes are more complex on polymer films. 1-Piperidinoanthraquinone doss not sensitise the photochemical degradation of nylon or cellulose acetate yarn. The results suggest that there is no definite relation between the ease of photoreduction of a dye and its ability to sensitise the photochemical degradation of textile fibres.     

Novel (Phenothiazinyl)Vinyl-Pyridinium Dyes and Their Potential Applications as Cellular Staining Agents

We report here the synthesis and structural characterization of novel cationic (phenothiazinyl)vinyl-pyridinium (PVP) dyes, together with optical (absorption/emission) properties and their potential applicability as fluorescent labels. Convective heating, ultrasound irradiation and mechanochemical synthesis were considered as alternative synthetic methodologies proficient for overcoming drawbacks such as long reaction time, nonsatisfactory yields or solvent requirements in the synthesis of novel dye (E)-1-(3-chloropropyl)-4-(2-(10-methyl-10H-phenothiazin-3-yl)vinyl)pyridin-1-ium bromide 3d and its N-alkyl-2-methylpyridinium precursor 1c. The trans geometry of the newly synthesized (E)-4-(2-(7-bromo-10-ethyl-10H-phenothiazin-3-yl)vinyl)-1-methylpyridin-1-ium iodide 3b and (E)-1-methyl-4-(2-(10-methyl-10H-phenothiazin-3-yl)vinyl)pyridin-1-ium tetrafluoroborate 3a′ was confirmed by single crystal X-ray diffraction. A negative solvatochromism of the dyes in polar solvents was highlighted by UV-Vis spectroscopy and explanatory insights were supported by molecular modeling which suggested a better stabilization of the lowest unoccupied molecular orbitals (LUMO). The photostability of the dye 3b was investigated by irradiation at 365 nm in different solvents, while the steady-state and time-resolved fluorescence properties of dye 3b and 3a′ in solid state were evaluated under one-photon excitation at 485 nm. The in vitro cytotoxicity of the new PVP dyes on B16-F10 melanoma cells was evaluated by WST-1 assay, while their intracellular localization was assessed by epi-fluorescence conventional microscopy imaging as well as one- and two-photon excited confocal fluorescence lifetime imaging microscopy (FLIM). PVP dyes displayed low cytotoxicity, good internalization inside melanoma cells and intense fluorescence emission inside the B16-F10 murine melanoma cells, making them suitable staining agents for imaging applications.     

Cardanol-Based Bis(azo) Dyes as a Gasoline 91 Colorant

Novel bis(azo) dyes were successfully prepared from the coupling of either natural cardanol or its hydrogenated derivative with a series of diazotized aromatic amines and diamines. These new dyes were fully characterized by NMR, infrared and UV–visible spectroscopy and mass spectrometry. The dyes are highly soluble in a variety of common organic solvents and gasoline as a consequence of the cardanol unit. The physical properties of gasoline according to American Society for Testing and Materials standard were unaffected by the presence of the bis(azo) dye derived from 1-(4aminophenylazo)-2-naphthol at a concentration of 6 ppm and the dye showed excellent stability over a 3 month period.     

Investigation of electrochemical degradation and application of e-paper dyes in organic solvents

To avoid environmental pollution due to organic dye solutions, the electrophoresis and degradation of dye in organic solvents such as alcohol were investigated. Many dyes were tested in the Indium tin oxide (ITO) electrode driving cell, and about 15 dyes moved under voltage driving. Both the curves of ultraviolet-visible (UV-Vis) and infrared (IR) spectra of the electrophoresis samples showed that the metal complexes Red 04 and Acid Black 1 were degradable in alcohol solution by electrochemical reaction. The cyclic volt-ampere curves of the samples from the electrochemical working station proved that electrochemical reactions took place. Based on the analysis of UV-Vis and IR spectra, the electrochemical degradation products of azo and metal complex azo dyes at lower voltage driving (1-5 V) in organic solvents are oxidized azobenzene, not hydrazine, which was found in the electrochemical degradation of dye water solutions. When the ITOelectrode is modified by a polyimide (PI) film to a thickness less than 4 μm, the electrochemical degradation of the dye in alcohol solution will not appear in the cyclic volt-ampere curves. A dye electrophoresis in organic solution flexible prototype e-paper display was formed and the display picture is shown.     

Some properties of dual fluorescence of methine dyes

Studies of the dependence of methine dye absorption and fluorescence properties on the molecular composition of the dyes, on solvent polarity and on the temperature of the sample were made. The results have confirmed our recent suggestion that the emission band of methine dyes in polar solvents is composed of molecular and excimer fluorescence. The spectral properties of different types of molecular composition of methine dyes indicated the centre in the dye molecule involved in excimer formation. On the basis of a liquid nitrogen temperature spectrum and the lifetimes of fluorescence it is suggested that this type of methine dye which can form the excimers has a strong tendency to aggregate in the ground states. These aggregates are able to quench the molecular fluorescence. An increase of solvent polarity causes disaggregation of dye molecules giving an increase of molecular fluorescence and an increased probability of excimer formation. Thus, in polar solvents the long-wavelength emission band arises.     

Pyrroloquinoline Based Styryl Dyes Doped PMMA,PS, and PS/TiO2 Polymer for Fluorescent Applications

This article presents two highly fluorescent donor-π-acceptor (D-π-A) moieties containing an electron-donating carbazole and phenothiazine donors fused with electron-withdrawing pyrrolo-quinoline acceptor dyes, PQC and PQPT. We also discussed the polymerization and film-forming process of dye PQC and PQPT doped in poly (methyl methacrylate) (PMMA) and polystyrene (PS) polymer to find their optical applications in polymer-based technology. We investigated the fluorescent properties of dyes PQC and PQPT from 0.01 to 1 wt% in poly(methyl methacrylate) (PMMA). We also investigated the changes in the spectrum shape and shift in wavelength with changes in poly(methyl methacrylate) (PMMA), polystyrene (PS), and TiO₂ doped in polystyrene (PS/TiO₂). The analysis of surface morphology of prepared polymer samples was done with the help of a scanning electron microscope. The thermal and photostability of synthesized dyes in poly (methyl methacrylate) (PMMA), polystyrene (PS), and TiO₂ doped in polystyrene (PS/TiO₂) were investigated to get detailed information owing to the application of fluorescent polymers in the field of optoelectronic, nanohybrid coatings in solar concentrators, etc.

Graphical Abstract

     

Three new five-coordinated mercury (II) dyes: Structure and enhanced two-photon absorption

A new donor-bridge-acceptor (D-π-A) type ligand (L: 4′-(4-[4-(imidazole)styryl]phenyl)-2,2′:6′,2″-terpyridine) with two-photon absorption and coordination ability was designed and synthesized. Self-assembly of the ligand with HgX₂ (X = Cl, Br, I) yielded a series of new coordination complexes (Dyes 1-3) with five-coordinated mercury (ΙΙ), which were characterized by single crystal X-ray diffraction determination. Solvent molecules and various weak interactions, including hydrogen bonds (C-H···N, C-H···X) and π-π interactions played significant roles in the final topological structures. Linear and nonlinear optical properties of the ligand and three dyes were described. Experimental results revealed that two-photon absorption cross sections of three dyes are extraordinary stronger than that of ligand.