Synthesized Azo Dye Research Articles

Thermostable Polarizing Film on the Basis of Poly (vinyl alcohol) and New Dichroic Synthesized Azo Dye for Optical Applications: Theoretical and Experimental Investigations

Quantum-chemical calculations using the Density Functional Theory (DFT) approach for structural analysis of the new dichroic mono azo dye: Sodium (E)-5-((4-carboxylatophenyl)diazenyl)-2-hydroxybenzoate (S) (trans isomer) was carried out using B3LYP methods with 6-311+G* basis set. After calculations, the new mono azo dye was synthesized. UV, FT-IR and 1H NMR spectra of the compound S are reported. The electronic spectrum of the mono azo dye S was also carried out in the water solution. Interpretation of absorption strips in UV region of spectrum was also reported. On the basis of the polyvinyl alcohol (PVA) and the new dichroic synthesized azo dye thermostable polarizer film absorbing in the UV region of spectrum (λmax=388 nm) with effect of polarization (PE) in the absorption maximum 97% was developed. The main spectral-polarization parameters (transmittance, optical density) of stretched PVA-films were measured and discussed.It was also established that oriented colored PVA-films is phenomenon of anisotropy of thermal conductivity (l|| / l^). Thermal conductivity in the direction of orientation (l||) is higher than in the direction perpendicular to the orientations (l^). The developed thermostable polarizer film was used in polarizing microscopes, circular polarizers, magnetometers, spectropolarimeters and electrical signals sensors.

Characterization and application of azo dye (E)-N-phenyl-4-(thiazole-2-yldiazenyl)aniline (PDA) for biomedical sterilization.

Sterilization is the certain and absolute decontamination of microorganisms totally from all manner of alive and active species. Sterilization devices used in the sterilization processes are between laboratory and external patient application devices of biomedical device technology, and they are designed to remove equipments from germs. The application potential of hetarilazo indole based azo dyes in the biomedical sterilization are known and azo dyes come into prominence in this class because of simplicity of their synthesis and procurement of low-cost raw materials. In this work, the application potential of a novel synthesized azo dye, (E)-N-phenyl-4-(thiazole-2-yldiazenyl)aniline was investigated as an indicator in the biomedical sterilization performing the electrochemical and spectroscopic characterizations. The application of indicator was tested by ethylene oxide, hydrogen peroxide and peracetic acid sterilization techniques introducing into various sterilization rolls.

On the structure of transition metals complexes with the new tridentate dye of thiazole series: Theoretical and experimental studies

The 1-[(5-Benzyl-1,3-thiazol-2-yl)diazenyl]naphthalene-2-ol (BnTAN) is a recently synthesized azo dye that can act as a tridentate ligand in complexes with transition metals. In a series of previous works, this analytical reagent was shown to be applicable for selective, reliable, express and relatively inexpensive determination of heavy metals in different objects through the spectrophotometric technique. Although the action of 1-(2-thiazolylazo)-2-naphthol (TAN) dyes as tridentate ligands has been suggested in the literature long time ago, due to the lack of experimental data, it was necessary to investigate the mechanism of formation and the structure of BnTAN complexes with the such transition metals as Cu(II), Zn(II) and Cd(II). Furthermore, the reactivity and properties of different acidity forms and conformers of BnTAN and related TAN dyes were not fully defined, so the determination of these properties by analysis of wavefunction was also necessary.Two standard spectrophotometric methods and voltammetric technique were used to determine the composition of complex of BnTAN with metals ions. All three experimental methods indicate that coordination ratio of metal:dye is equal to 1:2. Moreover, this study reports the stability and geometry of conformers of different forms (anionic/neutral/cationic) of BnTAN, along with a detailed analysis of electronic properties, reactivity and aromaticity of the most stable conformers of BnTAN forms. Each of the above forms has some difference in position of benzyl ring against the thiazole moiety, which is explained in terms of attraction and repulsion of these two fragments induced by partial atomic charges. The crucial influence of hydrogen bond and weak non-covalent interactions between naphthyl, aza- and thiazolyl fragments has been established.The quantum chemical calculations have shown that partial atomic charges of anionic, neutral and cationic forms can explain the reactivity of each BnTAN form, and have also clarified the mechanism of formation of metal complex through the connection of metal with phenol oxygen, thiazolyl nitrogen and one nitrogen of aza group – thus giving two five-membered metal-containing cycles and confirming that BnTAN acts as a tridentate ligand.The obtained results introduce novel and crucial information which can assist in understanding the mechanism of complex formation of BnTAN and display the strength and level of detail of applying quantum chemical methods to reveal the reactivity, energy properties, and electronic properties of this new dye.

Electrochemical behavior and voltammetric detection of fenitrothion based on a pencil graphite electrode modified with reduced graphene oxide (RGO)/poly(E)-1-(4-((4-(phenylamino)phenyl)diazenyl)phenyl)ethanone (DPA) composite film

A combination of a novel synthesized azo dye (E)-1-(4-((4-(phenylamino)phenyl)diazenyl) phenyl)ethanone and reduced graphene oxide was used to electrochemically modify the surface of a pencil graphite electrode. The surfaces of the modified electrodes were characterized using electrochemical techniques (cyclic voltammetry and electrochemical impedance spectroscopy) and spectroscopic techniques (scanning electron microscopy and attenuated total reflectance). This azo dye/reduced graphene oxide modified electrode was applied first time for the electrochemical detection of an organophosphorus pesticide, fenitrothion. The modified pencil graphite electrode displayed excellent performance for the detection of fenitrothion. Cyclic voltammetry was used to study the dependence of the scan rate on the peak current and peak potential and to determine the kinetic parameters for fenitrothion. Square wave voltammetry was used to determine the effect of pH on the peak potential and for the sensitive and selective detection of fenitrothion using the modified electrode. Satisfactory results were obtained with the proposed sensor for the analysis of FT in tomato samples.

Spectroscopic (Polarization, ExcitedState, FT-IR, UV/Vis and <sup>1</sup>H NMR) and Thermophysical Investigations of New Synthesized Azo Dye and Its Application in Polarizing Film

Quantum-chemical calculations using the Density Functional Theory (DFT) approach for structural analysis of a new azo benzene derivative: Sodium 6-amino-5-hydroxy-3-((E)-(2-methoxy-4-((E)-(4-sulfonatophenyl)diazenyl)phenyl)diazenyl)naphthalene-2-sulfonate (A) (trans isomer) was designed using B3LYP method with 6-311++G** basis set. The electronic absorption spectrum of the A in water solution was calculated using TDB3LYP/6-311++G** method. The excitation energies, electronic transitions and oscillator strengths for studied structure have also been calculated. On the basis of calculations a new dichroic azobenzene dye A was synthesized. The experimental UV-Vis, FT-IR and 1 H NMR spectra of the title molecule were presented. On the basis of polyvinyl alcohol (PVA) and the dichroic synthesized azobenzene dye A thermostable polarizing film absorbing in the seen region of the spectrum (λ max = 550nm) with Polarization Efficiency (PE) in the absorption maximum (λ max = 92%) and Stretching Degree (R s ) = 3.0 was developed. The experimental spectral-polarization parameters of stretched colored PVA-films were measured. During the work it was established that oriented PVA-films is phenomenon of anisotropy of thermal conductivity (λ ‖ /λ ⊥ ). Thermal conductivity in a direction of orientation (λ ‖ ) is higher than in a direction perpendicular orientations (λ ⊥ ).

Synthesis of fluorescent molecular probes based on cis-cinnamic acid and molecular imaging of lettuce roots

We synthesized azo dye- and fluorescence-labeled cis-cinnamic acid analogues possessing inhibitory activity against lettuce root growth and a trans-isomer without bioactivity as a control probe. The radicles incubated with the azo dye-labeled analogue were stained red, with their tips especially deeply dyed. The fluorescent images of the radicles incubated with each of these molecular probes depicted that the root cap was fluorescence-stained. However, images of the control radicles prepared by staining with the trans-isomer fluorescent probe did not show emission at the root cap. These contrasts suggest specific localization of the cis-cinnamate analogue at the columella cells.

Photo-electrochemical studies of chemically deposited nanocrystalline meso-porous n-type TiO2 thin films for dye-sensitized solar cell (DSSC) using simple synthesized azo dye

Nanocrystalline titanium dioxide (TiO2) thin films were deposited by successive ionic layer adsorption and reaction method onto fluorine doped tin oxide coated glass substrate at room temperature (300 K). Titanium trichloride and sodium hydroxide were used as cationic and anionic sources, respectively. The as-deposited and annealed films were characterized for structural, morphological, optical, electrical and wettability properties. The photoelectrochemical study of TiO2 sensitized with a laboratory synthesized organic dye (azo) was evaluated in the polyiodide electrolyte at 40 mW cm−2 light illumination intensity. The photovoltaic characteristics show a fill factor of 0.24 and solar conversion efficiency value of 0.032 % for a TiO2 thickness of 0.96 µm as compared to efficiency of 0.014 % for rose Bengal of the same thickness.

Electrochemical characterization of azo dye (E)-1-(4-((4-(phenylamino)phenyl)diazenyl)phenyl)ethanone (DPA)

An enormous range of possible dyes are available, especially as the starting molecules are readily available and cheap. As other dye classes become less viable from either an environmental or economic reasons, azo dyes come to the forefront. Therefore, electrochemical characterization of a novel synthesized azo dye (E)-1-(4-((4-(phenylamino) phenyl)diazenyl)phenyl)ethanone was achieved for the first time. Cyclic voltammetry, chronoamperometry and square wave voltammetry techniques were used to investigate the electrochemical behavior and electrocatalytic effect of azo dye (E)-1-(4-((4-(phenylamino) phenyl)diazenyl)phenyl)ethanone at pencil graphite electrode. Cyclic voltammograms were utilized to determine the effect of scan rate and pH on the peak current and peak potential. Chronoamperometry technique was used to determine diffusion constant, D and the type of adsorption isotherms. The kinetics parameters which were the apparent electron transfer rate constant, ks and charge transfer coefficient, α were calculated. Square wave voltammetry was used to verify responses of cyclic voltammetry technique.

Synthesis, spectral characterization, thermal, anticancer and antimicrobial studies of bidentate azo dye metal complexes

As a part of systematic investigation of biologically active compound, m-phenylene diamine, new azo dye ligand was synthesized by diazotization of m-phenylene diamine and coupled with coupling compound, p-methoxy benzaldehyde. A new series of Cr(III), Mn(II), Fe(III), Co(II), Ni(II), Cu(II), Zn(II) and Cd(II) complexes derived from this azo dye ligand (L) were synthesized. The structures of the ligand and metal complexes were confirmed by elemental analysis, spectroscopic studies (IR, UV–Vis, 1H NMR, mass spectrometry, electronic spectra, magnetic susceptibility and ESR), conductivity measurements, thermogravimetric analyses (TG-DTG) and X-ray powder diffraction. The molar conductance measurements of the complexes in DMF determine electrolytic nature of the complexes. On the basis of elemental and thermal analyses, magnetic moment, electronic and ESR spectral studies, an octahedral geometry was assigned for metal complexes. XRD data reflect that azo dye ligand and its Cr(III), Mn(II), Fe(III), Co(II), Ni(II), Cu(II) and Zn(II) complexes are amorphous while Cd(II) complex is crystalline. Also, the newly synthesized azo dye ligand, in comparison with metal complexes, is screened for its antimicrobial and anticancer activity against breast cancer cell line (MCF7). The results showed that Mn(II), Ni(II) and Zn(II) metal complexes have higher anti-breast cancer activity than free ligand.

Particle Size, Morphology and Color Characteristics of C.I. Pigment Red 57:1 : 1. Effect of Synthesis Conditions

The effects of synthesis conditions on characteristics of the calcium-azo complex pigment, C.I. Pigment Red 57:1, were studied. It was mainly considered that the industrially required synthesis conditions for lowering electrical conductivity of the pigment solution keeping pigment quality such as particle size and color characteristics. Three parameters were chosen as control factors during the synthesis. The first was the amount of hydrochloric acid added to transform sodium nitrite into nitrous acid. The second was the amount of calcium chloride added to insolubilize the synthesized azo dye. The final factor was pH control during the coupling reaction. The electrical conductivity and pigment aggregate particle size were dependent on the amount of hydrochloric acid and calcium chloride. Higher HCl concentration gave brighter yellowish-red color because of smaller particle aggregate size and narrower size distribution. Amount of charged ions in the synthesis process might affect the lake formation resulting different particle aggregate size and color shade.

Union Dyeing of Wool/Polyester Blend Fabric Using Sulphatoethylsulphone Dye Derivative of C.I. Disperse Yellow 23

This paper aims to synthesise, characterise and find out the properties of a model dye for convenient union dyeing of wool, polyester and wool/polyester blend fabric compared with C.I. Disperse Yellow 23. The reactive disperse dye was prepared containing sulphatoethylsulphone (SES) as a reactive group. The dye was synthesised by diazotization and coupling reaction. Firstly, we synthesized azo dye intermediate I using 1-aminobenzene-4-sulphatoethylsulphone diazotized and then coupled it with aniline. The synthesized azo dye intermediate I was diazotized and coupled with phenol to give dye 2. Different factors affecting the dyeability and fastness properties of SES dye 2 were thoroughly investigated on wool, polyester and wool/polyester blend fabrics in comparison with C.I. Disperse Yellow 23 dye 1. Maximum exhaustion and total fixation yield using sulphatoethylsulphone (SES) dye 2 were achieved on wool fabric at neutral pH 7. The dye showed high dyeing performance due to its nonionic reactive VS derivative. The dyeing results indicate high quality dyeing properties

Solvent Effects on the Electronic Spectra of Some Heterocyclic Azo Dyes

The influence of solvent polarity on the absorption spectra of some synthesized azo dye with heterocyclic moieties and <TEX>${\beta}$</TEX>-naphthol (1-3) have been investigated using a UV-Visible spectrophotometer. The spectral characteristics of the azo dyes (1-3) in different solvents at room temperature were analyzed. The solvatochromic empirical variables like <TEX>${\pi}^*$</TEX>, <TEX>${\alpha}$</TEX>, and <TEX>${\beta}$</TEX> have been used to discuss the solvatochromic behaviour of the dyes and to evaluate their contributions to the solute-solvent interactions. A multi-parameter regression model for quantitative assessment of the solute/solvent interaction and the absorption has been used to explain the solvent effect on azo dyes (1-3).

Synthesis of Some Novel Bis 1,3,4-Oxadiazole Fused Azo Dye Derivatives as Potent Antimicrobial Agents

bis(5-(furan-2-yl)-1,3,4-oxadiazol-2-yl)azo dyes were synthesized by multistep reaction sequences, which is diazotized and coupled with different napthols and quinoline. Structure of newly synthesized compounds were characterized and confirmed by IR, NMR and Mass spectral studies. The newly synthesized azo dye fused with (5-(furan-2-yl)-1,3,4- oxadiazole) were screened for their acute toxicity and gross behavioral studies and in-vitro anti-microbial activity. Synthesized compounds exhibit significant biological activity and can certainly hold greater promise in discovering safer biologically active molecules.

A highly versatile stable optical sensor based on 4-decyloxy-2-(2-pyridylazo)-1-naphthol in Nafion for the determination of copper

A new optical chemical sensor based on the recently synthesized azo dye, 4-decyloxy-2-(2-pyridylazo)-1-naphthol (DPAN), immobilised in Nafion membranes is reported. The sensing membranes cast onto glass substrates and integrated into a flow-through measuring cell were homogeneous, transparent, mechanically stable and showed no evidence of reagent leaching. The DPAN/Nafion sensor was used for the determination of Cu(II) which forms a blue coloured complex with DPAN. The main parameters of the computer controlled flow system incorporating the flow-through optical sensor, a multi-port selection valve and a peristaltic pump were optimized. The duration of the time during which the sample was aspirated into the flow system governed the sensitivity and working range of the Cu(II) determination thus making the system easily adaptable to a wide range of Cu(II) concentrations in the samples analyzed. The copper content in solutions obtained after dissolving turnings of certified aluminium bronze and bronze standards was determined using 90 s aspiration time while a 600 s aspiration time was required for the determination of the Cu(II) concentration in tap water. Satisfactory agreement with atomic absorption spectroscopy (AAS) results and the bronze standards specifications was obtained in all cases.