Azomethine Dyes Research Articles

Microwave Assisted Synthesis, Spectrofluorometric Characterization of Azomethine as Intermediate for Transition Metal Complexes with Biological Application.

Azomethine (1, 5 - Dimethyl - 2 - phenyl -[(3, 4, 5 -trimethoxybenzylidene) amino] -1, 2 - dihydropyrazol - 3 - one) (DTAD) was synthesized by the reaction of 4-aminophenazone with 3,4,5 trimrthoxybenzaldehyd by microwave irradiation. Physicochemical studies such as electronic absorption, molar absorptivity, oscillator strength, dipole moment, florescent quantum yield were investigated in order to explore the analytical potential of azomethine dye. Azomethine go through the solubilization in different micelles and may be used as a probe or quencher to determine the critical micelle concentration (CMC) of SDS and CTAB. It's coordinate to metal salt through the pyrazol-3-one oxygen and the azomethine nitrogen. The structure of ligand and its meal complexes was elucidated by IR, (1)H, (13)C-NMR, EI-MS spectroscopic methods and elemental analysis. The antibacterial activity of these compounds were first tested in vitro by the disc diffusion assay against two Gram-positive and two Gram-negative bacteria, and then the minimum inhibitory concentration was using chloramphenicol as reference drug. The results showed that compound 1.1 is better inhibitor of both types of tested bacteria as compared to chloramphenicol.

Influence of microwave irradiation on hypochlorite decolorisation of synthetic dyes

In this study three synthetic dyes were treated using hypochlorite or combination of hypochlorite and microwave irradiation in order to investigate factors which determine decolorisation of the investigated compounds. An azo dye (C.I. Reactive Orange 16 - RO16), an azo methine dye (C.I. Basic Yellow 28 - BY28) and an antraquinone dye (C.I. Acid Blue 111 - AB111) were used for experiments. Hypochlorite stability as well as the influence of microwaves on hypochlorite stability was also investigated.

Computational Insights into Excited-State Proton-Transfer Reactions in Azo and Azomethine Dyes.

State of the art density functional theory approaches are employed to provide an accurate description of the photophysical properties of azodyes and Schiff bases displaying intramolecular hydrogen-bonding features. These compounds exist as tautomeric mixtures at the ground state and, in the case of Schiff bases, an excited-state intramolecular proton transfer (ESIPT) occurs upon excitation. The experimentally observed photophysical properties are discussed here in light of the theoretical findings. To rationalize the different experimentally observed radiative behavior of the azo and azomethine structures, a nonradiative decay pathway that is possibly active in such systems is determined. The characterization of this deactivation path, tested for two related compounds exhibiting different fluorescence quantum yields, enables us to disentangle the different and contrasting effects governing the excited-state behavior of these molecular systems.

Development of kinetic models for photoassisted electrochemical process using Ti/RuO2 anode and carbon nanotube-based O2-diffusion cathode

A coupled photoassisted electrochemical system was utilized for degradation of C.I. Basic Yellow 28 (BY28) as a cationic azomethine dye under recirculation mode. Experiments were carried out by utilizing active titanium/ruthenium oxide (Ti/RuO2) anode and O2-diffusion cathode with carbon nanotubes (CNTs). Transmission electron microscopy (TEM) image of the CNTs demonstrated that CNTs had approximately an inner and outer diameter of 5nm and 19nm, respectively. Then, the dye degradation kinetics was experimentally examined under various operational parameters including BY28 initial concentration (mg/L), current density (mA/cm2), flow rate (L/h) and pH. Based on the generally accepted intrinsic elementary reactions for photoassisted electrochemical process (PEP), a novel kinetic model was proposed and validated for predicting the kapp. The developed kinetic model explicitly describes the dependency of the kapp on BY28 initial concentration and current density. A good agreement was obtained between the predicted values of kapp and experimental results (correlation coefficient (R2)=0.996, mean squared error (MSE)=2.10×10−4 and mean absolute error (MAE)=1.10×10−2). Finally, in order to profoundly evaluate and compare the accuracy of the suggested intrinsic kinetic model, an empirical kinetic model was also developed as a function of main operational parameters, and an artificial neural network model (ANN) by 3-layer feed-forward back propagation network with topology of 5:9:1. The performance of the mentioned models was compared based on the error functions and analysis of variance (ANOVA). A comparison according to the errors function demonstrated that the experimental data were fitted appropriately by all of the proposed models with an adequate accuracy. Moreover, ANOVA results showed that there is no significant discrepancy among the predicted values of the three proposed models.

Synthesis, Spectroscopic, Physicochemical, Crystal Structure and DFT Studies of 4,5,6,7-tetrahydro-1-benzothiophene-3-carbonitrile Based Azomethine Dyes

Synthesis, Spectroscopic, Physicochemical, Crystal Structure and DFT Studies of 4,5,6,7-tetrahydro-1-benzothiophene-3-carbonitrile Based Azomethine Dyes

Luminescent guest–host composite films based on an azomethine dye in different matrix polymers

New hybrid guest/host composite films obtained by dispersing a light-emitting azomethine dimer into three different matrix polymers have been studied. Poly(methyl methacrylate) (PMMA), UDEL polysulfone (PSU) and chitosan were chosen as host matrix. Differential scanning calorimetry, polarized light microscopy, scanning electron microscopy and atomic force microscopy measurements revealed the composite morphology and their thermal properties. UV–vis and fluorescence spectroscopy indicated the influence of polymer matrix on the azomethine dye optical properties. The composite films exhibited strong photoluminescence emission when excited with maximum absorption wavelength. It was concluded that polysulfone is a good candidate in guest/host composite obtaining.

Solvatochromism, spectral properties and antimicrobial activities of new azo–azomethine dyes with N2S2O2 donor set of atoms

Six new azo–azomethine dyes, H2Ln (n=1–6), with N2S2O2 donor set of atoms have been prepared via condensation reaction of 1,10-diaza-4,7-dithiadecane, I, with substituted azo-coupled salicylaldehyde. The dyes were characterized by IR, UV–Vis and 1HNMR spectroscopic methods as well as elemental analysis. The solvatochromic behavior of the dyes was also probed by studying their UV–Vis spectra in four pure organic solvents of different polarities and a meaningful correlation was observed. Furthermore, all prepared dyes were assayed for their antibacterial and antifungal activities by disc diffusion method. The results indicated that all prepared dyes show good inhibition against Staphylococcus epidermidis and Bacillus cereus and did not show any antibacterial activity against Escherichia coli as compared to standard drugs.

Synthesis, characterization, solvatochromism and biological properties of 2,2′-((1E,1′E)-((1,2,5-oxadiazole-3,4-diyl)bis (azanylylidene))bis(methan-ylylidene))bis(4-(phenyldiazenyl)phenol)

Azo–azomethine dyes 2-((4-amino-1,2,5-oxadiazol-3-ylimino)methyl)-4-(phenyl diazenyl)phenols (2a–h) have been synthesized by condensation reaction of 3,4-diamino-1,2,5-oxadiazole with 2-hydroxy-5-[(E)-(aryldiazenyl)]benzaldehyde (1a–h) in methanol. The structures of dyes have been characterized by elemental analysis, mass, IR, UV–Vis, 1H and 13С NMR spectroscopy. UV–Vis absorption spectra indicated enol–keto tautomeric and positive solvatochromism in compounds 2a–h which is dependent on the substitution, solvent, pH and environment temperature. The synthesized compounds were investigated for their in vitro antioxidant activity by diphenylpicrylhydrazyl assay. Compounds substituted with electron donating groups, such as, alkyl and methoxy groups showed moderate antioxidant activity. The in vitro antibacterial activity of all compounds was determined by disk diffusion method. The test compounds showed varying degree of inhibition against B. cereus and S. aureus strains.

New 1,2,4-triazole-based azo–azomethine dye. Part III: Synthesis, characterization, thermal property, spectrophotometric and computational studies

A new 1,2,4-triazole-based azo–azomethine compound, H2L, has been prepared by condensation reaction of 1-(3-formyl-4-hydroxyphenylazo)-4-ethylbenzene with prepared triazole-based diamine. The structure of H2L was characterized by using FT-IR, UV–Vis and 1H NMR spectroscopic methods as well as elemental analysis. Hard model chemometrics method has been used to determine the formation constants of zinc(II), copper(II), nickel(II) and cobalt(II) complexes of H2L in DMSO by UV–Vis spectrophotometric method. Solvatochromic behavior of the dye has been also investigated in some organic solvents with different polarities. Thermal properties of the prepared dye was examined by thermogravimetric analysis. Results indicated that the framework of the dye was stable up to 245°C. Furthermore,1H chemical shifts and UV–Vis of H2L were studied by the gauge independent atomic orbital (GIAO), continuous set of gauge transformations (CSGT) and time-dependent density functional theory (TD-DFT) methods respectively at the level of density functional theory using B3LYP/6-311+G(d) basis sets in DMSO. The computational data are in reasonably good agreement with the experimental data.

The triazine-based azo–azomethine dyes; spectroscopy, solvatochromism and biological properties of 2,2′-((2,2′-(6-methoxy-1,3,5-triazine-2,4-diyl) bis(oxy)bis(2,1-phenylene))bis(azan-1-yl-1-ylidene)bis(methan-1-yl-1-ylidene))bis(4-phenyldiazenyl)phenol

The macrocyclic azo–azomethine dyes 2,2′-((2,2′-(6-methoxy-1,3,5-triazine-2,4-diyl) bis(oxy)bis(2,1-phenylene))bis(azan-1-yl-1-ylidene)bis(methan-1-yl-1-ylidene))bis(4-phenyl diazenyl)phenol and its substituted derivatives were synthesized and characterized by elemental analysis, mass, FT-IR, UV, 1H and 13С NMR spectroscopy. The solvatochromism of dyes was evaluated in various solvents. The effects of substitution, pH as well as environment temperature on the electronic absorption spectra are also reported. The newly synthesized compounds are explained on a basis of positive solvatochromism behavior of compounds due to intramolecular hydrogen bond in enol–keto tautomeric and dipole moment changes. In addition, the antioxidant and antibacterial activities of compounds were evaluated. The synthesized compounds display antioxidant properties, but did not show a remarkable antibacterial activity.

Solvatochromic and electrochemical properties of new thermally stable azo–azomethine dyes with N2S2O2 donor set of atoms

A new series of azo–azomethine dyes with N2S2O2 donor set of atoms have been synthesized via condensation reaction of α,α′-bis(2-aminoethylthio)-1,3-xylene and substituted azo-coupled salicylaldehyde. The dyes were characterized by IR, UV–Vis and 1H NMR spectroscopic methods as well as elemental analysis. The solvatochromic behavior of the dyes was probed by studying their UV–Vis spectra in four pure organic solvents of different polarities and a meaningful correlation was observed. The electrochemical properties of the dyes have been also studied by cyclic voltammetry in DMSO. Moreover, thermal properties of the prepared dyes were examined by thermogravimetric analysis and results indicated that the framework of the dyes is stable up to 260°C.

New 1,2,4-triazole-based azo–azomethine dyes. Part II: Synthesis, characterization, electrochemical properties and computational studies

A new series of monoiminated 1,2,4-triazole-based azo–azomethine dyes have been synthesized via condensation reaction of 4-amino-3-methyl-5-mercapto-1,2,4-triazole with various substituted azo-coupled salicylaldehyde. The dyes have been characterized by using FT-IR, UV–Vis and 1H NMR spectroscopic methods as well as elemental analysis. The electrochemical behavior of the dyes has been investigated by cyclic voltammetry in DMSO at five different scan rates. Solvatochromic behavior of the dyes has been also investigated in four organic solvents with different polarities. Furthermore, the 1H chemical shielding of the dyes were studied by the gauge independent atomic orbital (GIAO) method at the level of density functional theory (DFT).

Synthesis and Spectral Study of New Azo - Azomethine Dyes and its Copper (II) Complexes Derived from Resorcinol, 4-Aminobenzoylhydrazone and 4-Amino antipyrine

Four new azo dyes L1, L2, L3 and L4, were prepared by linking benzaldehyde p-aminobenzoylhydrazone (3), p-hydroxybenzaldehyde p-amino- benzoylhydrazone ( 4 ), naphthaldehyde p-aminobenzoylhydrazone (5) and p-methoxybenzaldehyde paminobenzoylhydrazone (6) to resorcinol and through diazo-coupling reactions. Mixed -ligand dinuclear complexes with general stoichiometry [Cu2L(amino antipy.)2]Cl2 (11, 12, 13 and 14) was synthesed from azo ligands and bidentate ligand (4-aminoantipyrine) with copper. The structures of both azo dyes and their complexes were identified by elemental analyses (C.H.N), FTIR, 1 H-NMR,

カラー写真像を形成しているアゾメチン型色素溶液の光変退色; モデルマゼンタ色素-カルボニル化合物-アルコールの脱気溶液の光退色生成物の同定

カラー写真像を形成しているアゾメチン型色素溶液の光変退色; モデルマゼンタ色素-カルボニル化合物-アルコールの脱気溶液の光退色生成物の同定

カラー写真像を形成するアゾメチン型色素溶液の光変退色; イエローモデル色素-カルボニル化合物-アルコールの脱気溶液の光退色生成物の同定

カラー写真像を形成するアゾメチン型色素溶液の光変退色; イエローモデル色素-カルボニル化合物-アルコールの脱気溶液の光退色生成物の同定

ChemInform Abstract: Synthesis and Application of Some Azo and Azomethine Dyes Containing Pyrazolone Moiety.

AbstractChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.

Synthesis and Application of Some Azo and Azomethine Dyes Containing Pyrazolone Moiety

Abstract3‐Amino‐1‐phenyl‐4,5‐dihydro‐1H‐pyrazol‐5‐one (1) was used as starting material for the synthesis of a number of azo compounds 3a–3c and azomethine derivative 4. The deblocking of 3a–3c and 4 gave rise to 5a–5c and 6 in which a free amino was revealed. The diazonium salts of 5a–5c and 6 were coupled with several phenols to produce a number of bis azo compounds 7a–7c and 8a–8c with azomethine in position 4 and azoic group in position 3. The prepared dyes were structurally confirmed by elemental analysis, spectral methods and applied to different fibers (wool, polyester and blend of wool/polyester) as disperse dyes and their fastness properties were measured.

A one-pot synthesis of some novel tetrakisazo disperse dyes bearing twenty-membered macrocyclic poly(azomethine)

Multiple-chromophore-containing dyes have been synthesized by azo coupling of twenty-membered poly(azomethine) dye 1 and 3-nitro- (2a) or 2,4-dinitrobenzene-1-diazonium tetrafluoroborate (2b) in solvents of various polarity (water, chloroform) in the presence or absence of dibenzo-18-crown-6 as phase transfer catalyst. The dyeing ability of the dyes was investigated as well as spectral and kinetic study of azo coupling was performed. The obtained disperse dyes are suitable for dyeing Nylon and polyester fibers from light reddish-brown to dark brown colors with good uniformity of dyeing as well as light, washing and sublimation fastness.

4-[(E)-Phenyldiazenyl]-2-[(E)-phenyliminomethyl]phenol

The title azo–azomethine dye, C19H15N3O, was synthesized by the reaction of 2-hydr­oxy-5-[(E)-phenyl­diazen­yl]benzaldehyde with aniline. With respect to the azo double bond, the two attached benzene rings display a trans configuration with a C—N=N—C torsion angle of 178.5 (3)°. The structure is stabilized by intra­molecular O—H⋯N and inter­molecular C—H⋯O hydrogen bonds.

ジヒドロキシベンジリデンアニリンおよびそのナフチル導入型アゾメチン系色素を配位子とするアルミニウムキレート錯体の合成と性質

ジヒドロキシベンジリデンアニリンおよびそのナフチル導入型アゾメチン系色素を配位子とするアルミニウムキレート錯体を合成し, 置換基や骨格による熱分解性や溶解性, 吸収スペクトル, 蛍光性などへの影響を検討した。アルミニウムキレート錯体は, 種々の置換基をもつ配位子とジエチルアルミニウムクロリドの反応により, 金属と配位子1:1の錯体として得られた。アルミニウムキレート錯体は, 加熱により二量体などに変化し, 高い温度で分解することが推定された。キレート錯体の紫外可視吸収において, 極大吸収波長および吸収端は相当する配位子に比べどちらも長波長側にシフトした。置換基としてはニトロ基をもつキレート錯体が最も長波長シフトを示した。また, アルミニウムキレート錯体には蛍光性が見られ, 蛍光強度は相当する配位子に比べ著しく増加し, 置換基をもたないものに比べ置換基をもつとどの置換基でも増加した。