Disazo Dyes Research Articles

Five new heterocyclic disazo dyes derived from the 4-position: Synthesis, characterisation, and acute toxicity evaluation

In the present work, five novel heterocyclic disazo dyes (AA3a−AA3e) were synthesised. The characteristic properties of these synthesised dyes were examined, and their elemental analysis values were calculated. The dyes were characterised by the FT-IR, 1H NMR, and 13C NMR spectroscopy. The impacts of several solvents on the absorption abilities of the synthesised compounds were analysed by a UV–vis spectrophotometer. Also, the absorption properties and tautomeric changes of the dyestuffs in the existence of inorganic acids and bases were investigated. Apart from these analyses and examinations, given the possibility of their release into the environment especially during their potential subsequent applications, the acute toxicity of each synthesised dyes to Gammarus roeseli (Crustacea: Amphipoda) was tested in the study. The current study is of great importance in the sense that it gives precious information on the acute toxicity levels of the dyestuffs AA3a−AA3e as well as their synthesis and spectral properties.

Newly Synthesized Aminothiazole Based Disazo Dyes and Their Theoretical Calculations

In this study, ten novel disazo dyes based on aminothiazoles (4a-e, 5a-e) were synthesized in the first section. By using their 1H-NMR, FT-IR, and UV-Vis spectra, these synthesized dyes’ structures were verified. In the second section, the density functional theory (DFT) was used to calculate the molecular geometry, vibrational frequency and molecular electrostatic potential (MEP) diagram in the ground state using the B3LYP level and the 6-311 G(d,p) basis set. UV-vis data were obtained using the Gaussian 09 TD-DFT Cam-B3LYP 6-311 G ++ (d,p) basis set. To explore the chemical shift values, the gauge independent atomic orbital (GIAO) approach was used. Time-dependent DFT (TD-DFT) approach was used to determine the HOMO–LUMO calculations. As a consequence of our research, it was found that the experimental values and the computational spectroscopic values of the synthesized disazo compounds were consistent.

An alternative strategy for the synthesis of disazo disperse dyes and their application on polyester fabric

Due to the limitations of dye solubility in reaction solvents, the crosslinking reaction between two monoazo disperse dyes will tend to result in low yield and multiple by-products. In this work, an alternative synthetic strategy was used to prepare three disazo disperse dyes, which involved first synthesizing crosslinked coupling components with diisocyanate compounds followed by diazotization with a double diazonium salt. The structures of these new dyes were characterized by nuclear magnetic resonance (NMR), mass spectrometry (MS), and fourier transform infrared spectroscopy (FT-IR) analysis, and the spectral characteristics of the dyes in dimethylformamide (DMF) solutions were evaluated. Three synthesized disazo dyes were applied to the polyester fabrics by high-temperature and hot-melt dyeing processes. The results showed that a higher yield was obtained for all three dyes, and each of the dyes had relatively high molar extinction coefficient and slow dyeing rate on the polyester fabric due to the existence of the double-chromophore. Therefore, a certain amount of carrier or solubilizer had to be added to the dyebath to improve the dyeing rate. At 220 °C for 2.5 min, a satisfactory dyeing effect was achieved, which demonstrated that the disazo disperse dyes exhibited excellent colorfastness properties. Compared with high-temperature dyeing, thermosol dyeing produced higher dye uptake, build-up, and fastness properties, and this process was suitable for the dyeing of polyester fabrics with the disazo disperse dyes.

Development of the molecular engineering of disazo dye sensitizers and TiO2 semiconductor surface to improve the power conversion efficiency of dye-sensitized solar cells

Employing organic sensitizers is potentially advantageous in dye-sensitized solar cells (DSSCs) compared with ruthenium(II) complexes since they comprise earth-abundant elements and have high molar absorption coefficients and notable structural diversity. However, the molecular engineering of organic dyes is of great interest as they can be designed to maximize light harvesting. Herein, a family of disazo dye molecules containing multiple donor and acceptor groups with two π-spacer parts (AD1-AD5) was employed as photosensitizers to fabricate novel DSSCs based on modified TiO2 semiconductor (GNT/AD1-AD5). Modification of the TiO2 surface was carried out with doping of nitrogen and graphene into the titanium dioxide substrate. The effect of an extended π-conjugation system and linking groups of dye molecules in photovoltaic performance has been examined. Moreover, the power conversion efficiency has been compared in the case of utilizing two different redox mediators including iodine and cobalt-based electrolytes. GNT/AD4 with triiodide/iodide electrolyte achieved the highest solar to electrical energy conversion efficiency (η = 3.82%, VOC = 0.862 V), in the series.

Analysis of Relationship Between Some Disazo Dyes Derived from 2,4-Dihydroxyquinoline and Its Anticancer and DNA Binding Properties by Density Functional Theory

It was studied some physical and chemical properties of 2,4-dihydroxy quinoline derivative diazo dyes by theoretical methods. Six different solvents were used to determine the solvatochromic behavior and absorption of the compounds, and the experimental results were compared with the theoretical data obtained from quantum chemical calculations. DFT calculations were carried out to obtain the geometric, electronic and some chemical reactivity parameters of the compounds. The atom in molecule, natural bond orbital, density of state, non-covalent interaction, Fukui function, electron localization function, and electron delocalization range analyzes of the compounds were performed to determine the relationship between the electronic properties and the DNA binding capacity and the cytotoxicity against HeLa and PC3 cancer cell lines. It was observed that the compounds substituted with –Cl and –NO2 had higher DNA binding and higher anticancer effect. Besides the positions of the substituents, the electron density in the bonds, the delocalization index values and the distribution of the nucleophilic and electrophilic attack sites are among the important factors determining the reactivity of the compounds. In addition, the HOMO energies of the compounds with better DNA binding properties were calculated higher than the other compounds.

Synthesis and absorption properties of five new heterocyclic disazo dyes containing pyrazole and pyrazolone and their acute toxicities on the freshwater amphipod Gammarus roeseli

AbstractIn this study, five new heterocyclic disazo dyes containing pyrazole and pyrazolone were synthesised (3a‐3e). The synthesised disazo dyes were characterised by elemental analysis and Fourier Transform–infrared and proton nuclear magnetic resonance spectroscopy. The effects of two different solvents upon the absorption ability of the dyes substituted with electron‐withdrawing and electron‐donating groups were examined in detail. In addition, the acute toxicity of each synthesised azo dye was evaluated using a short‐term bioassay with Gammarus roeseli (Crustacea: Amphipoda) for 48 hours. According to the evaluations, the dyes 3a, 3b and 3d were categorised as slightly toxic, and the dyes 3c and 3e as practically non‐toxic. Considering the toxicity of the dye 3a, it was determined that the substitution of the electron‐withdrawing group in the azo dye resulted in more toxicity, while the substitution of the electron‐donating group resulted in less toxicity. It was also found that the presence of the strongly electron‐withdrawing group resulted in the azo dye becoming more toxic in comparison with the presence of the weakly electron‐withdrawing group, but that the presence of the strongly electron‐donating group resulted in the azo dye becoming less toxic in comparison with the presence of the weakly electron‐donating group. It is contended that this study is novel and of great importance in terms of synthesising new azo dyes, investigating their absorption properties and assessing their acute toxicities.

New disazo dyes derived from aminopyrazoles: synthesis, spectroscopic properties, computational study and structural properties

AbstractIn this study, five new pyrazolyazo pyrazole dyestuff syntheses are reported. For this purpose, 5‐amino‐4‐arylazo‐3‐methyl‐1H‐pyrazoles were diazotised and coupled with 3‐amino‐5‐hydroxy‐1H‐pyrazole. Fourier Transform–infrared, ultraviolet‐visible and proton nuclear magnetic resonance spectroscopy were used to investigate the properties of aminopyrazole‐based dyes obtained in this study. The maximum absorption wavelengths of these dyes in various solvents were determined. The theoretical calculations of the molecules in the ground state were performed with the density functional theory/Becke 3‐parameter and Lee–Yang–Parr/6‐311G(d,p) method by using the Gaussian 0.9 W program. The results were compared with the corresponding experimental data. Acid‐base and substituent effects on the absorption spectra of dyes were also examined and reported.

Novel heterocyclic disazo dyes containing pyrazole and phenylpyrazole. part 1: Synthesis, characterization, solvent polarity and acid-base sensitive characteristics

A series of diazotised aniline and aniline derivative compounds were reacted with solution of malononitrile in pyridine at 0–5 °C were obtained 1a-1m compounds. Then 4-arylazo-3,5-diamino-1H-pyrazole (2a-2m) derivatives were synthesized by coupling arylazo malononitrile compounds with hydrazine. Finally, the synthesized pyrazole derivative 2a-2m compounds were again diazotised. By reacting these diazotised compounds with 3-amino-5‑hydroxy-1-phenylpyrazole, the new thirteen heterocyclic disazo dyes (3a-3m) were joined the dye literature and the dye industry. The structures of these newly synthesized compounds were characterized using elemental analysis and spectroscopic methods such as Fourier transform infrared spectroscopy-Attenuated total reflectance (FT-IR-ATR), 1H-Nuclear magnetic resonance (1H NMR) spectroscopy and mass spectroscopy. Then solvatochromic properties and solvent effect in dimethyl sulfoxide, dimethyl formamide, acetonitrile, acetic acid, methanol and chloroform were investigated. In addition, the effects of organic and inorganic acids and bases on the absorption spectra of the compounds and the substituent effect of the phenyl ring-bound groups were investigated.

Дослідження впливу хімічних властивостей активних барвників на процес фотодеструкції забарвлень бавовняних трикотажних полотен

Today, reactive dyes are the most popular class used to obtain dyed cotton textile materials, and the only one for cotton knitwear. Colours obtained with reactive dyes are highly resistant to washing due to the formation of a covalent bond of the dye with the polymer. In connection with the emergence of new classes of bi- and polyfunctional reactive dyes, it is urgent to establish the regularities of the influence of their chemical structure on the lightfastness of the obtained colours. The aim of the work is to study the influence of chemical properties of reactive dyes, namely the chemical structure of chromophore, the number and type of active groups, on the lightfastness of colours obtained on cotton knitted fabrics. The study was carried out using a cotton knitted fabric prepared in an appropriate way. The dyeing of the textile material was carried out using mono-, bi- and polyfunctional dyes in the appropriate modes. In terms of chemical structure, the dyes under study were azo and disazo dyes, anthraquinone, phthalocyanine, and formazan dyes. According to the chromophore chemical structure the studied dyes were monochlorotriazine, dichlorotriazine, vinyl sulfonic and bifunctional with a monochlorotriazine / vinyl sulfone active group. For the obtained knitted fabric samples, the kinetics of colours photodestruction was investigated. Insolation of the samples was carried out on the RF 1201 BS (REFOND) device with a mercury-tungsten lamp with periodic determination of samples colour differences using a PCE-TCR 200 colorimeter. The article presents the results of a study of the dependence of dyed cotton knitted fabric samples lightfastness on the chemical properties of reactive dyes. The chemical class of dyes has been established, which have low resistance to light in comparison with other investigated chromophore systems. In addition, the dependence of the cotton knitted fabric colours lightfastness on the chemical structure and the number of active groups was found.

Physical Structure Analysis and Optical Properties of Sudan III Thin Film

Background: Sudan III is known red disazo dye possess a hydroxyl group which is sensitively to interact with others molecules such as CO2, O2, SO2 through hydrogen bonding. Methods: Fabrication of Sudan III thin film for sensor technology application has been carried out by using PVD method. The physical structure that is crystallinity of this film has been investigated by using XRD method. Results: The XRD spectra of powder Sudan III shows crystalline structure while the XRD spectra of thin film results of the PVD method, which is deposited on substrate glass slide shows amorphous structure. There are no differences in the crystallinity content of Sudan III thin film that exposure to acetone and alcohol vapor. The interplanar distance of crystals plane is about 28.47 nm, the average crystallite size is about 35.6 nm and the average molecular chain separation is about 37.9 nm. Sudan III thin film result of the PVD method shows an interesting optical characteristic (absorption). There are significantly different between UV-VIS spectra Sudan III thin film compared to the UV-VIS spectra of Sudan III solution. The UV-VIS spectra of the Sudan III thin film shows a decreasing of peak intensity in visible wavelength which indication of orientation effect of molecule on substrate surface. The aborption peak at UV region for Sudan III thin film shows a shifting to the long wavelength compared to the Sudan III in form of solution.

Studying the stability of Solvent Red 19 and 23 as excise duty components under the influence of controlled factors

In this study, we examine the chemical stability of two disazo dyes, namely Solvent Red 19 and 23 (SR 19 and SR 23), under simulated conditions. Both dyes are considered to be chemically stable under normal exploitation conditions and therefore, are used extensively as excise duty components that enable a rapid visual verification of the tax levels that were imposed on fuel products as well as identifying fuel usage. However, the results from this study confirmed that the colour of the samples that had been fortified with either SR 19 or SR 23 fades under the influence of external conditions such as UV-A irradiation and temperature over time. The UV-A irradiation was the dominant factor that was responsible for the colour of the samples to fade in two designed experiments that were carried out independently for two model systems. The analysis of the UV/Vis and fluorescence spectra as well as the interpretation of the changes that were observed in the chromatographic profiles provided substantial evidence that the colour fading was caused by the photodegradation of the disazo dyes, which also occurs in non-polar media including fuel products. SR 19 is more stable than SR 23.

The application of disperse dyes derived from 4-bromoaniline and 3-chloroaniline on to polyester fabric

A series of new disazo disperse dye compounds based on 4-amino-2-chlorophenylazo-4-bromobenzene intermediate were prepared by linking various arylamines and phenolic derivatives to this intermediate through diazo coupling reactions. The structures of the azo compounds were confirmed by FT-IR, 1 H NMR, 13 C NMR and UV-visible spectral data. The results of the UV-vis absorption spectra of some of the dyes showed near-infrared absorptions around 573-800 nm. The results of the colour fastness to washing and sublimation gave an excellent value of grade 5. The light fastness values were found to be technically acceptable with the grey-scale grade of 5 to 6-7. Also, the rubbing fastness was observed to be grade 3/4 to 4. KEY WORDS : Disazo dyes, Spectral absorption, Polyester, Fastness, Near-infrared absorption Bull. Chem. Soc. Ethiop. 2019 , 33(1), 127-134 DOI: https://dx.doi.org/10.4314/bcse.v33i1.12

Anticancer, antimicrobial, and DNA protection analysis of novel 2,4-dihydroxyquinoline dyes

A new series of 2,4-dihydroxyquinoline derived disazo dyes has been synthesized by the reaction of 5-amino-4-phenylazo-3-methyl-1H-pyrazole derivatives with 2,4-dihydroxyquinoline. The structures of the obtained dyes were identified by various spectrophotometric methods such as FT-IR, 1H-NMR, and elemental analysis. The synthesized compounds were also examined for different biological activities, including DNA protection, antimicrobial, and anticancer activities. Compound 3b was found most effective on Gram-positive bacteria. A DNA protection assay was applied to all compounds, and it was found that compounds 3h and 3j had a high capacity for binding to DNA. Besides, compounds 3h and 3j showed cytotoxicity against HeLa and PC3 cancer cell lines. These compounds could potentially be used as drugs or drug additives based on their effects on bacterial and cancer cell lines.

Disazo dyes containing pyrazole and benzothiazole moieties: synthesis, characterization, absorption characteristics and tautomeric structures

Eight newly synthesized disazo disperse dyes containing benzothiazole and pyrazole moieties were prepared by diazotization of 2-aminobenzothiazole, coupling with 3-aminocrotononitrile as active methylene, cyclization reactions with hydrazine hydrate and phenyl hydrazine, diazotization again and finally coupling with dimedone, dioxane, 1-methyl imidazole and 2-methyl imidazole, respectively. Their structures were characterized with spectroscopic methods (FT-IR, 1H-NMR, 13C-NMR) and solvatochromic properties were studied with UV–Vis spectroscopy in different solvents. Tautomeric structures of synthesized dyes were also examined in detail.

Antimicrobial activities and absorption properties of disazo dyes containing imidazole and pyrazole moieties

ABSTRACTThe newly synthesized thirteen disazo dyes containing imidazole and pyrazole cycles (3a-3m) were carried out by diazotization reaction of 5-amino-4-arylazo-3-methyl-1H-pyrazoles (2a-2m) and coupling reaction with 1-methyl imidazole. Structures of synthesized azo dyes were characterized by UV–Vis, FT-IR, 1H-NMR, elemental analysis and their solvatochromic properties were studied in DMSO, DMF, methanol, acetic acid and chloroform. In addition, the antimicrobial activities of dyes against twelve pathogenic bacteria were examined in detail and all dyes showed antimicrobial activity against different bacterial strains.

Photochemical Degradation of Disazo Dyes, R-Salt Derivatives, on Dyed Cotton

ABSTRACTDirect disazo dyes, R-salt derivatives, were synthesized and examined. The dyes were prepared by coupling of appropriate components with tetrazotized diacyl derivatives of aromatic diamines. Derivatives of dicarboxylic acids with the general formula HOOC―(CH2)n―COOH (n = 0 ÷ 4) were used as acylating agents. Photochemical degradation rates of dyes on dyed cotton fabric were studied. Compositions of azo-hydrazone tautomers, their aggregates, and their decay rates in UV-Vis light were determined. It was assumed that the length of aliphatic chain in the molecule affects the rate of its photochemical degradation T1/2, tautomeric composition, and dyes aggregation in azo and hydrazo forms.

A combined experimental and DFT investigation of disazo dye having pyrazole skeleton

Disazo dye containing pyrazole skeleton has been synthesized. The structure of the dye has been confirmed by using FT-IR, 1H NMR, 13C NMR, HRMS spectral technique and elemental analysis. The molecular geometry and infrared spectrum are also calculated by the Density Functional Theory (DFT) employing B3LYP level with 6-311G (d,p) basis set. The chemical shifts calculation for 1H NMR of the title molecule is done by using by Gauge-Invariant Atomic Orbital (GIAO) method by utilizing the same basis sets. The total density of state, the partial density of state and the overlap population density of state diagram analysis are done via Gauss Sum 3.0 program. Frontier molecular orbitals such as highest occupied molecular orbital (HOMO) and lowest unoccupied molecular orbital (LUMO) and molecular electrostatic potential surface on the title molecule are predicted for various intramolecular interactions that are responsible for the stabilization of the molecule. The experimental results and theoretical values have been compared.

New coumarin-based disperse disazo dyes: Synthesis, spectroscopic properties and theoretical calculations

5-Amino-4-arylazo-3-methyl-1H-pyrazoles (3a-l) have been diazotised and coupled with 4-hydroxycoumarin to give rise to the coumarin-based disperse disazo dyes (3a-l). The newly synthesized twelve coumarin-based disperse disazo dyes have been characterized by using the elemental analysis and the spectral methods. The solvatochromic behavior of these dyes in various solvents is evaluated. Substituent, acid and base effects on the visible absorption spectra of the dyes substituted with electron-withdrawing and electron-donating groups at their o-, m-, p-position are also reported in detail. Molecular geometries and spectroscopic properties of the compounds considered in this work are also analyzed by using ab initio calculation methods based on the density functional theory (DFT) in the ground state. The theoretical results obtained from DFT are compatible with the experimental results.

Disazo dyes containing pyrazole and indole moieties: Synthesis, characterization, absorption characteristics, theoretical calculations, structural and electronic properties

The newly synthesized thirteen disperse disazo dyes 3a–3m were prepared by diazotization of 5-amino-4-arylazo-3-methyl-1H-pyrazoles 2a–2m and coupling with 2-methyl indole. Their structures were characterized by UV–vis, FT-IR, 1H NMR and elemental analysis. Solvatochromic properties in different solvents were studied. Also, the effects of acid and base on the visible absorption spectra of the dyes were informed. Besides, the theoretical vibrational frequencies have been scaled and compared with the corresponding experimental data. 1H NMR spectra were recorded and chemical shifts of the molecules were compared to TMS by using the Gauge-Independent Atomic Orbital (GIAO) method. A study on the electronic and optical properties, absorption wavelengths, excitation energy and dipole moment is performed using DFT method. NBO analysis is carried out to picture the charge transfer between the localized bonds and lone pairs. All spectroscopic properties examined with the experimental techniques were supported with the computed results.

Sulfuric disazo dye stabilized copper nanoparticle composite mixture: synthesis and characterization

A copper nanoparticle–sulfuric disazo dye (Cu–SD1) composite was synthesized using the sol–gel method.