Synthesis and colour spectroscopic investigation of some hemicyanine dyes

New hemicyanine dyes with a benzo[2,3‐b;2′,3′‐b′]bis‐furo[3,2‐d]pyrazolium nucleus were prepared. Spectroscopic investigations were carried out in 95% ethanol for all the synthesised cyanine dyes and/or in pure solvents which have different polarities for some selected dyes. Structural identification was carried out via elemental analysis, infra‐red and proton nuclear magnetic resonance spectral data.     

Simulation,synthesis, characterisation and dyeing properties of a fluorescent hemicyanine dye

In this study, a hemicyanine dye, trans‐4‐(4‐(diethylamino)styryl)‐1‐ethylpyridinium bromide (DYE‐BD), was synthesised and simulated. The maximum absorption wavelength of DYE‐BD was calculated with the same basis set by using the Gaussian 09 software based on different methods, while time‐dependent density functional theory was applied to simulate the maximum emission wavelength of the designed dye. The changes in enthalpy and Gibbs free energy were simulated at the b3lyp/6‐31G(d) level, and energy changes in the luminescence process were assessed using mathematical methods. Furthermore, DYE‐BD was used to colour acrylic fabric following the typical dyeing procedure for cationic dyes. The photostability of the synthesised dye was analysed using quantum theory and mathematical methods. The synthesised dye, analysed using the Ecological Structure Activity Relationships class program, had no toxicity to aquatic life, while the acrylic fabrics dyed with DYE‐BD met the fluorescent orange requirements for background and combined performance materials according to the EN ISO 20471:2013 standard.     

Extended conjugation in di- and tri- arylmethane dyes. Part 3. The effects of increased planarity in Victoria Blue dyes

The synthesis of novel derivatives of the Victoria Blue series of dyes containing the 3,6-bis(dimethylamino)fluoren-9-yl moiety is reported. The consequent increased planarity of the system results in a large bathochromic shift of the x-band compared to the parent compound.     

An argon laser induced polymerization photoinitiated by both mono- and bichromophoric hemicyanine dye-borate salt ion pairs. The synthesis, spectroscopic, electrochemical and kinetic studies

A series of homodimeric hemicyanine dyes based on (p-dimethylaminostyryl)benzothiazolium, (p-dimethylaminostyryl)benzoxazolium, (p-dimethylaminostyryl)-2,3,3-trimethyl-3H-indolium residues were synthesized. Several photoredox pairs containing mono- and bichromophoric hemicyanine dyes, possessing benzothiazole, benzoxazole or indolinium group linked by 5 or 10 methylene groups have been evaluated as novel photoinitiators for free radical polymerization induced with the argon-ion laser visible emission. In tested photoredox pairs, hemicyanine dye acts as an electron acceptor and it is coupled with borate anion which is an electron donor. The photochemistry of the series of bichromophoric hemicyanine borates: 1,5-bis-[N,N′-(2,2′-(4-N,N-dimethylamino)styryl)benzothiazolium]pentane, 1,10-bis-[N,N′-(2,2′-(4-N,N-dimethylamino)styryl)benzothiazolium]decane (S5, S10), 1,5-bis-[N,N′-(2,2′-(4-N,N-dimethylamino)styryl)benzoxazolium]pentane, 1,10-bis-[N,N′-(2,2′-(4-N,N-dimethylamino)styryl)benzoxazolium]decane (O5, O10) and 1,5-bis-[N,N′-(2,2′-(4-N,N-dimethylamino)styryl)-3,3,3′,3′-tetramethyl-3H-indolium]pentane, 1,10-bis-[N,N′-(2,2′-(4-N,N-dimethylamino)styryl)-3,3,3′,3′-tetramethyl-3H-indolium]decane (I5, I10) was compared to the photochemistry of structurally related monochromophoric hemicyanine borates (S1, O1, I1).     

The synthesis, characterization, thermal and optical properties of copper, nickel, and vanadyl complexes derived from azo dyes

Two, novel, tetradentate Schiff-base ligands, namely bis-5-phenylazosalicylaldehyde diethylenetriimine and bis-5-[(4-methoxyphenyl)azo]salicylaldehyde diethylenetriimine, as well as their Cu²⁺, Ni²⁺, and VO²⁺ complexes, were synthesized and characterized using elemental analysis, infrared and also UV–Visible spectroscopy, ¹HNMR and mass spectra. The thermal stability of the free ligands and the related metal complexes, as determined using differential scanning calorimetry and thermal gravimetric analysis, were found to be thermally stable upto 240–275 °C depending on the type of ligand and the central metal atom. The λ_max of the ligands and their transition metal complexes in the region 300–800 nm are discussed. The novel metal complexes offer potential for application as recording media owing to both their absorption spectra in the blue-violet light region and high thermal stability.     

Synthesis and antimicrobial activity of certain novel monomethine cyanine dyes

A series of novel monomethine cyanine dyes were synthesized by using 3-methyl-5-substituted-1-phenyl-pyrano[2,3-c]pyrazole derivatives 2a–c. Reaction of equimolar ratios of 2a–c with 2(4)-methyl heterocyclic quaternary salts afforded the corresponding monomethine cyanines 3a–c. Reaction of compound 5 with 2(4)-methyl heterocyclic quaternary salts gives monomethine 6a–c. Condensation reaction of equimolar ratios of compounds 7 and 9a,b with 2(4)-methyl heterocyclic quaternary salts afforded the corresponding monomethine cyanines 8a–c and 10a,b respectively. The new synthesized monomethine cyanine dyes were identified by elemental analyses, IR, ¹H-NMR and Ms spectral data. The electronic absorption spectra in ethanolic solution of novel monomethine cyanine dyes were measured and the antimicrobial activity of some selected monomethine cyanine dyes was discussed.     

4,4′-二氨基苯甲酰替苯胺系列偶氮染料的合成及应用

选定 4,4′ 二氨基苯甲酰替苯胺为重氮组分 ,以水杨酸、γ酸为偶合组分 ,控制一定反应条件 ,合成了红棕色、红色、紫色苯甲酰替苯胺型系列直接染料 ,并在铬羊皮上作染色试验 ,染成的有色革具有较高的耐磨擦坚牢度和较高的日晒牢度。     

两种杯[6]芳烃的红外光谱和拉曼光谱研究

研究了两种对－叔丁基杯〔６〕芳烃的红外和拉曼光谱。对－叔丁基杯〔６〕芳烃Ｉ的环状的分子内缔合氢键和部分甲基化的（１,３,５－三甲基）－对－叔丁基杯（６）芳烃Ⅱ的三中心氢键在红外光谱中有明显反映杯（６）芳烃的ｐｉｎｃｈｅｄ ｃｏｎｅ（紧锥型）构象也得到了证明,而两种杯（６）芳烃氢键构象和强度的不同导致了二者的拉曼谱图也存在较大的差异。     

Microwave-assisted solvent-free synthesis and spectral properties of some dimethine cyanine dyes as fluorescent dyes for DNA detection

A series of dimethine cyanine dyes were synthesized in a fast, efficient and high yield by the condensation of quaternary salts with 1H-indole-3-carbaldehyde in the presence of piperidine under solvent-free microwave irradiation. The products were identified by ¹H NMR, IR, UV–vis spectroscopy and elemental analysis. The absorption and fluorescence properties of the dyes in both the free state and DNA or BSA were investigated. Significant enhancement of the fluorescent quantum yield was observed for all the dyes in the presence of DNA, with one compound demonstrating excellent sensitivity as a fluorescent probe.     

The kinetics of sorption of basic dyes from aqueous solution by sphagnum moss peat

The kinetics of sorption of three basic dyes, namely, Chrysoidine (BO2), Astrazon Blue (BB3) and Astrazone Blue (BB69) onto sphagnum moss peat have been investigated. The study focuses on the application of three sorption kinetic models for predicting the uptake of basic dyes. The sorption behaviour is found to be second order, based on the assumption of a pseudo-second order mechanism. The rate constant of sorption, the equilibrium capacity and initial sorption rate with the effect of various peat doses and initial dye concentrations have also been predicted.     

论偶氮染料的偶氮-腙互变异构

偶氮染料存在着偶氮-腙互变异构。其中包括两个概念, 一是偶氮体和腙体是一对异构体, 由其结构不同导致其发色和化学性能不同;二是两种异构体在满足某种条件下可以互变。对偶氮体或腙体结构的识别是研究偶氮染料结构与性能的基础。当前染料学术界和产业界对偶氮-腙互变异构有两大误识:偶氮体即腙体, 两者不必加以区分;以及两者既为互变异构, 则时刻处于变化中而无法进行区分。本文针对上述误识, 讨论了两种异构体的结构与性能关系。一个偶氮染料的偶氮体及醌腙体是两种结构与性能, 如紫外-可见光谱吸收、化学反应性能及牢度不同的化合物。通常仅以某种异构体结构为稳定状态存在, 折中结构结决定了它的颜色和染色性能。两者仅在某种特定的条件下可以互相变化。这些条件取决于化合物结构、所处环境条件, 如温度、溶剂、介质pH等环境因素对偶氮-腙平衡的影响。介绍了用其红外光谱、拉曼光谱、核磁波谱、质谱以及晶体的X衍射谱来确认互变异构体的方法。     

The synthesis of novel perylene-like dyes and their aggregation properties in Langmuir and Langmuir-Blodgett films

The synthesis of novel perylene-like dyes with different length and molecular structure of terminal chains substituted to the main perylene core is described. The dyes are able to form compressible and stable monolayers at the air-water interface (Langmuir films), which can be easily transferred onto solid substrates (Langmuir-Blodgett films). In the Langmuir and Langmuir-Blodgett films, the dye molecules show tendency to creation of self-aggregates, both in the ground and excited electronic states. The influence of the molecular structure of the substituents on the aggregation properties is observed and discussed.     

High-temperature thermal and X-ray diffraction studies, and room-temperature spectroscopic investigation of some inorganic pigments

Inorganic Cr- and Mn-containing pigments of different structural types were investigated by high-temperature and spectroscopic methods. The differential scanning calorimetry in the temperature interval 298-1723 K was applied to measure temperatures of phase transition and melting of the studied compounds. High-temperature X-ray diffraction in the range 298-1173 K was used for the determination of the thermal expansion coefficients for the first time. Factor group analysis was used to predict general vibration modes of pigments and determine the activity of these vibrations in Raman and IR spectra, the Assignment of bands in Raman, IR and diffuse reflectance spectra was undertaken.     

The intramolecular capture of thermally generated merocyanine dyes derived from naphthopyrans: Photochromism of 5-(diarylhydroxymethyl)-2H-naphtho[1,2-b]pyrans

A series of 2H-naphtho[1,2-b]pyrans bearing a diarylmethanol unit at C-5 have been synthesised by the addition of an excess of an aryllithium reagent to alkyl 2H-naphtho[1,2-b]pyran-5-carboxylate precursors. These naphthopyrans show photochromism when exposed to ultraviolet irradiation and also generate intense colours at low pH through triarylmethine cation generation. However, photochromism of the triarylmethine cation derived from the naphthopyran unit could not be detected. An irreversible cascade process initiated by the thermally-induced ring-opening of the diarylmethanol substituted 2H-naphtho[1,2-b]pyrans in the presence of an acid catalyst afforded novel benzopentalenonaphthalenone dyes.     

High-pressure synthesis,crystal structure,and physical properties of NaAlB14 single crystals

Pure NaAlB₁₄ single crystals were successfully synthesized directly from Na, Al, and B at high pressure and high temperature, different from the previously reported method, that is, synthesized from Na₂B₄O₇, Al, and B. The growth of NaAlB₁₄ single crystals was promoted by increasing the reaction temperature. The atomic structures of NaAlB₁₄ single crystal along the [100], [010], [001], and [021] axes were characterized by using a scanning transmission electron microscope. The Raman spectra of NaAlB₁₄ were investigated theoretically and experimentally, and they showed the expected oscillations of the covalent framework. In addition, photoluminescence spectra indicated that NaAlB₁₄ is a semiconductor luminescence material with red (1.68 eV) and near-infrared (1.50 and 1.36 eV) emission characteristics. The band structure revealed that NaAlB₁₄ is an indirect band gap semiconductor with a wide band gap of 2.22 eV.     

Recent progress in synthesis,growth mechanisms,and electromagnetic wave absorption properties of silicon carbide nanowires

With the research and development of nanomaterials, one-dimensional (1D) nanowire structures have received a lot of attention due to their unique physical and chemical properties. Among them, silicon carbide nanowires (SiC NWs) have low density, excellent oxidation resistance, dielectric properties, and electromagnetic (EM) wave absorption properties, which can well meet the development needs of civilian equipment and military weaponry. SiC NWs have outstanding research and application potential in the field of EM wave absorption. However, comprehensive summaries of SiC NWs have not been available so far. Based on this, this paper reviews the research progress of SiC NWs microwave absorbing materials, various micro-morphologies of SiC NWs are introduced in detail, as well as diverse preparation strategies and multiple growth mechanisms are also stated. Ultimately, recent advances in research progress of SiC NWs and their composites in EM wave absorption are elaborated, along with the future research directions of SiC NWs in the field of EM wave absorption.     

Thermodynamic investigation of methanol and dimethyl ether synthesis from CO2 Hydrogenation

The thermodynamics involved in the catalytic hydrogenation of CO₂ have been examined extensively. By assuming that methanol and dimethyl ether (DME) are the main products, two reaction systems each consisting of two pararell reactions were analyzed and compared in terms of the equilibrium yield and selectivity of the useful products, methanol and DME. The calculation results demonstrated that the production of DME allows much higher oxygenate yield and selectivity than that of methanol.     

Desorption and transfer processes in different classes of dyes

We report an analytical approach to study dye desorption and transfer processes in aqueous environment. The study was conducted simulating standard laundry washes using two different donor textiles, a polyester textile dyed with Disperse Blue 79 and a cotton textile dyed with Reactive Red 239, and two acceptor textiles, undyed cotton and polyester, respectively. Dye bleeding/solubilization from a donor textile to the solution was investigated through UV–visible absorbance analysis, while the dye absorption onto acceptor textile was quantified by UV–visible reflectance analysis. Dye desorption and transfer processes were investigated in water and surfactant solutions at different concentrations. A desorption and transfer model for the two classes of dyes was hypothesized by performing kinetic experiments. The results show that both processes depend on the presence of surfactants for the disperse dye. Conversely, the presence of surfactants has little effect on the reactive dye. Finally, the presence of an acceptor polyester significantly increases the bleeding of the disperse dye, while the presence of an acceptor textiles less influences the total release of the reactive dye.     

The use of reactive dyes in protein separation processes

The salient points of the chemistry of triazine based reactive dyes judged to be of interest to biochemists are summarised and the various alternative reactive systems and chromophores used in reactive dyes outlined. The development of the use of reactive dyes in dye affinity chromatography is discussed, parallels being drawn between textile dyeing and immobilisation techniques to provide suggestions for improvements in technique. The properties of the matrix are considered and structural features in the dye responsible for protein attraction analysed. The recent tailoring of dye structures to enhance utility in dye affinity chromatography and progress in the scaling up of high performance liquid affinity chromatography is reviewed.     

热敏染料FH—102的合成

归纳了热敏染料ＦＨ－１０２的不同合成方法,并进行了工艺选择。对中间体及产品的合成研究进行了总结与讨论。