Azo Derivatives Research Articles

Extraction-Chromogenic Systems for Vanadium(V) Based on Azo Dyes and Xylometazoline Hydrochloride

Liquid-liquid extraction-chromogenic systems for vanadium(V) based on xylometazoline hydrochloride (XMZ) and azo derivatives of resorcinol (ADRs) were studied. The following ADRs were used: 4-(2-thiazolylazo)resorcinol (TAR), 5-methyl-4-(2-thiazolylazo)resorcinol (MTAR), and 6-hexyl-4-(2-thiazolylazo)resorcinol (HTAR). Concentration of the reagents, pH of the aqueous medium and shaking time were subjects of optimization experiments. The chloroform-extracted ternary complexes were of composition 1:1:1. The molar absorptivity coefficients (el), absorption maxima (l), constants of extraction (Log K), and fractions extracted (E%) were found to be e553 = 2.50 ´ 104 dm3 mol-1 cm-1, Log K = 3.5, and E = 96% (ADR = TAR); e550 = 1.88 ´ 104 dm3 mol-1 cm-1, Log K = 3.4, and E = 98% (ADR = MTAR); and e554 = 2.62 ´ 104 dm3 mol-1 cm-1, Log K = 5.0, and E = 99.5% (ADR = HTAR). The Sandell's sensitivities and Beer's law limits were determined as well.

Simultaneous measurement of hydrogen carbonate and acetate anions using biologically active receptor based on azo derivatives of naphthalene.

A novel receptor based on azo-derivatives of 1-naphthylamine (2-((E)-((4-chloro-3-(trifluoromethyl)phenyl)imino)methyl)-4-((E)-naphthalene-1-yldiazenyl)phenol(2) abbreviated CTNP was successfully designed and synthesized. Its sensing properties were studied deeply. Systematic studies of CTNP with HCO3- and AcO- anions in DMSO disclosed that there is hydrogen-bonding between CTNP and incoming anions. Significant changes in the visible region of the spectrum, as well as a drastic color change of CTNP from pale yellow to red, observed due to interaction as mentioned earlier. The stoichiometry of [CTNP: HCO3- or AcO-] complexes and association constants determined through Job's method and Benesi-Hildebrand (B-H) plot, respectively. Taking into account the analysis results, CTNP performs the selective recognition of sub-millimolar concentrations of HCO3- and AcO- efficiently. The antifungal activity of the receptor was tested against Aspergillus brasiliensis and Aspergillus niger. CTNP exhibited excellent antifungal activity against both strains. CTNP also represented antibacterial activity against Gram-positive bacteria: Staphylococcus epidermidis. It was cleared that designed receptor can be applied under physiological conditions for a long duration.

Azo Derivatives of Pyrocatechol, Resorcinol, and Salicylic Acid as Collectors for Sulfide Ore Flotation

Heterocyclic and aromatic azo derivatives of pyrocatechol, resorcinol, and salicylic acid have been investigated as collectors for the flotation of sulfide ores. The acid-base properties of the compounds were studied, their solubility in an alkaline solution was determined. It was established that the fixing of reagents on the surface of the ore occurs mainly by the chemical mechanism. Adsorption constants were calculated. It was found that most of the studied reagents exhibit collective properties with respect to sulfide copper—nickel ore. The use of mixtures of azo compounds with potassium butyl xanthogenate leads to an increase in the degree of extraction of nickel and copper, as well as the quality of the concentrates, in comparison with one butyl xanthogenate.

Carbon‐Supported Organic Electrode Materials for Aqueous Rechargeable Lithium‐Ion Batteries

AbstractElectro active organic compounds represent one of the most capable electrode materials for the next generation green and sustainable rechargeable lithium ion batteries. In this context, we highlight the synthesis of an organic electrode material of azo derivative; diazoaminobenzene (DAAB) by diazotization method followed by lithiation using conventional technique. The electrochemical performances of the electro‐active species are examined by Cyclic Voltammetry, Galvanostatic Cycling with Potential Limitation and Potentio‐electrochemical Impedance Spectroscopy in an aqueous saturated Li2SO4 electrolyte. DAAB has shown considerable progress in terms of cyclic performance, better rate capability and high reversible capacity. The electroactivity of active species are enhanced by the addition of carboxy‐functionalized carbon nanotubes (CNTs‐COOH) as an additive. The half‐cell of lithiated diazoaminobenzene/CNTs‐COOH (dLiDAAB) vs. SCE delivers a capacity of 173.7 mA h g−1 up to 10 cycles at 0.08 mA. The full cell configuration dLiDAAB | aq. Saturated Li2SO4 | 2‐[1H‐indol‐2‐yl (1H‐indol‐3‐yl) methyl] phenol (b‐IMP) delivered a discharge capacity of 81.99 mA h g−1 in the potential window of −0.2 V to 1.2 V. The battery performance of the cell has been increased significantly by the influence of CNTs‐COOH group with 96.95% columbic efficiency. This agreeable result markably suits this material as an anode in aqueous rechargeable lithium batteries for future needs of energy technology.

4-Nitro-Azo Dye-Sensitized Optical Behavior of Organic/Inorganic Hybrid Networks in Zirconium-Based Thin Films: Effect of Cu Co-doping

The considerable attention on organic–inorganic compounds motivated us to study the effect of incorporation of new azo derivative, (2-hydroxy-3-methoxy-5-((4-Nitrophenyl)diazenyl) benzaldehyde), as an applicable organic molecule, in the structure of zirconium-based sol–gel thin films. The driving force behind our study is to see whether the possible coordination of organic and inorganic counterparts leads to the modification of the physical characters of the samples. The study on the UV/Vis transmittance and FTIR spectra of samples confirms that a combination of functional groups with the inorganic bonds is created. The improvement in the photoluminescence intensity is observed due to the lower concentration of dimer in the 1% azo-doped thin film. The effect of the addition of copper on the optical characteristics of samples doped with 1% azo is also studied. The increase in the copper concentration showed to be an intelligent method to achieve higher PL intensity.

One‐pot three‐component synthesis of novel 2‐(3‐nitro‐phenyl)‐quinazoline‐4‐carboxylic acid derivatives

AbstractA simple and easy synthesis of 2‐(3‐nitro‐phenyl)‐quinazoline‐4‐carboxylic acid (3) has been successfully developed through a one‐pot three‐component condensation reaction of (2‐amino‐phenyl)‐oxo‐acetic acid sodium salt (1) obtained from the hydrolysis of isatin with ammonium acetate and 3‐nitrobenzaldehyde. Some novel quinazoline‐ester derivatives 4‐7 were then obtained by the reaction between the new compound 3 and various alcohols. Then, quinazoline‐amide derivatives 10‐14 were synthesized from the reaction of various amines and 2‐(3‐nitro‐phenyl)‐quinazoline‐4‐carbonyl chloride (8), obtained by the reaction of compound 3 with SOCl2. Finally, some novel quinazoline‐azo derivatives 17‐19 were synthesized by the coupling reaction between β‐dicarbonyl compounds and the novel amino‐quinazoline derivative compound 15, obtained by reduction of nitro‐quinazoline derivative compound 11. Thus, a new series of quinazoline‐4‐carboxylic acid, ester, amide, and azo derivatives was synthesized and fully characterized by 1H NMR, 13C NMR, IR, and mass spectrometry analysis.

Synthesis and characterization Some of heterocyclic compounds from Nitrogen derivative

This paper involves the synthesis of new oxazepine derivatives by multi-reaction steps. The first step synthesis azo derivative from 2-naphthol with 3-aminoacetophenone. The second step was the condensation reaction between ketone group of the azo compound and different primary aromatic amines (4-amino phenol, 3-nitro aniline and 4-methyl aniline) to yiled new azo Schiff base compounds (S1-S3) respectively. In the final step, Oxazepine compounds (L1-L3)and (L4-L6)were prepared from reaction imine compounds (S1-S3) with maleic and phthalic anhydride in toluene as solvent. All these derivatives were characterized by melting point, FTIR, HNMR and 13CNMR.

Amine-Functionalized Spin Crossover Building Blocks.

Bistable spin crossover complexes such as [Fe{HB(pz)3}2] (pzH = pyrazole) show promise for sensor applications and electrically‐controlled data storage units, but exploiting their potential hinges on their integration into a functional environment. We here present a system enabling such covalent post‐functionalization steps in both symmetric and asymmetric patterns, based on the amine‐functionalized complex [Fe{HB(4‐NH2pz)(pz)2}2], obtained by reduction of the nitro analogue. The building block aspects of [Fe{HB(4‐NH2pz)(pz)2}2] are showcased by its transformation into amide, imine and azo derivatives, which are structurally and magnetically characterized. All tris(pyrazolyl)borate complexes retain the spin crossover properties of their parent compound, with spin crossover temperatures ranging from 350 to 430 K. The transition parameters are correlated with the electronic properties of the functionalizing group, opening the possibility of fine‐tuning the spin crossover properties of the building block as it is integrated in the environment of choice.

Synthesis and anti-bacterial activity of some azo compounds

Some azo compounds were prepared by the reaction of 4-amino benzamide with benzoyl chloride forming N-benzoyl-4-amino benzamide, the later was diazotized to give N-benzoyl-4-((substituted phenyl)diazenyl)benzamide (1-6). The compounds were characterized by F.T-IR, 1H-NMR and 13C-NMR. The azo derivatives (1-6) were tested for their antibacterial activity against (S. aureus, S. epidermidis, E. coli and P. aeruginosa) by using disc diffusion method. The minimum inhibitory concentrations (MICs) of the compounds also calculated by agar streak dilution method. The azo derivatives show moderate activity against the used bacteria.

Photoacoustic effect of azo derivatives modified by click reagents and parceled by liposomes

Photoacoustic (PA) imaging has been highlighted as one of the latest and the most promising biophotonic diagnostic modalities. As promising contrast agents, near-infrared (NIR) light-absorbing agents are highly in great demand. Here, the PA and photothermal (PT) effects of a series of NIR absorbing azo derivatives were characterized. Interestingly, compared with tetracyanoethylene (TCNE) and 7,7,8,8-tetracyanoquiodimethane (TCNQ), the click reagent 2,3,5,6-tetrafluoro-7,7,8,8-tetracyanoquiodimethane (F4-TCNQ) caused the red shift to near infrared (NIR) region for the peaks of PA intensity of molecules. Moreover, symmetrical molecular structure of NIR dyes had better PA effect. The M2a (clicked by TCNQ) molecules were embedded into hydrophobic phospholipid bilayer of liposomes (M2a⊂L) and internalized into human breast cancer Michigan Cancer Foundation-7 (MCF-7) cell. The toxicity of the cell was low, because the cell viability reached amost 100%, which was evaluated through CCK-8 assays to determine the metabolic viability of MCF-7 cells, while the cell PA intensity was high (1.5 × 103). The systematical research of the NIR dyes not only provided a series promising NIR dyes for imaging and treatment, but also guided the design of contrast agents and PT agents which had high PA and PT effects.

Synthesis and spectroscopic characterization of medicinal azo derivatives and metal complexes of Indandion

The development of new and more effective antibiotic agents is necessary for human health. Herein, we have prepared the series of azo-derivatives of 1,3-indandion and metal complexes (Cu2+, Zn2+, Ni2+ and Mn2+) with these azo derivatives like 3-hydroxy-2-[phenyldiazenyl]-1H-inden-1-one (HPDIO), 3-hydroxy-2-[2-methylphenyldiazenyl]-1H-inden-1-one (HMPDIO),3-hydroxy-2-[2-nitrophenyldiazenyl]-1H-inden-1-one (HNPDIO) and 3-hydroxy2-[2-chlorophenyldiazenyl]-1H-inden-1-one (HCPDIO) have been successfully synthesized and screened against some bacteria. The appearance of –NN- peak at 1400-1500 cm−1 with disappearance of NH2 peak at 3500 cm−1 in FTIR spectra and chemical shift at 4.07–4.05 ppm and appearance of multiplet at 8.0–7.5 ppm for phenyl protons confirmed the synthesis of new azo derivatives. The appearance of, C–N sharp peak at 102 ppm, aromatic carbon peak in the range of 115–135 ppm, C–OH sharp peak at 192 ppm and CO peaks at 160–187 ppm and appearance of molecular ion peaks at 250 m/z, 264 m/z, 295 m/z and 284 m/z respectively further gives strong indication for the synthesis of proposed azo derivatives. Further, the XRD analysis of azo derivatives confirmed that these derivatives have cubic geometry. A relationship between anti-bacterial activities and structure of synthesized compounds have been established, the addition of electron donating group (for example methyl group) on the compound (HMPDIO) showed remarkable results which were equal to standard drug ciproxin against B. subtilis. Furthermore, the metal complexes of HCPDIO with Zn(II) and HNPDIO with Cu(II) showed more anti-bacterial activity against E.coli, P.aeruginose, B.subtilis and S.aureus than other metal complexes and azo derivatives. The compounds also screened against antioxidant as well as chymotrypsin activity and HCPDIO gives maximum inhibition against antioxidant activity than standard drug (BHA). All the ligands give good inhibition results against chymotrypsin activity except HCPDIO.

Synthesis and switching properties of new derivatives of azoresveratrol

The synthesis and response upon light irradiation of azoresveratrol and six derivatives are reported. While UV irradiation of para-hydroxy trans compounds leads to thermally unstable cis isomers, the para-methoxy and the para-phosphoric ester substituents result in reaching a high conversion and increasing the thermal stability. In addition, the phosphoric ester azo derivative presents similar properties in organic and aqueous solutions, opening the way towards biological applications.

On the Charge-Transfer Excitations in Azobenzene Maleimide Compounds: A Theoretical Study.

Photoswitchable systems with charge-transfer (CT) transitions have gained much attention during the recent years because of their many emerging applications. CT transitions themselves are of fundamental importance from physical, chemical, engineering, and molecular modeling points of view because they depend on the modified intramolecular electronic structure. CT transitions in azobenzene (AB) were observed when substituted with the maleimide (MI) functional group. This work represents a systematic theoretical study of excited states of the AB-MI structures of eight azo derivatives. In addition to the two main azo transitions (π → π* and n → π*), our calculations show a CT occurring between the azo moiety as a donor and the MI group as an acceptor. The CT mechanism can be characterized based on both the number and the position of the MI fragments. MI groups in the azo structure result in low-energy transitions, changing the order of the main transitions by introducing a CT character. Calculations using both density functional theory (DFT) and high-end molecular orbital theories confirm the CT character of these derivatives, although the order of excited states was found to differ depending on the chosen level of theory. We present here the first theoretical investigation of the electronic excited states (nπ*CT and ππ*CT) and corresponding transitions for this class of compounds. The computational results showed that the CT mechanism in AB-MI derivatives can occur via two pathways: planar and twisted. Our findings are expected to be of substantial interest, especially in the area of molecular optoelectronics and in the design of responsive materials.

Synthesis and spectral characterization of some new azo benzothiazole derivative and relative compounds

A series of azo benzothiazole derivatives (2a–m) were prepared by coupling of the appropriate arylamine diazonium salts with 2-(benzo[d]thiazole-2-yl)-3-oxo-pentadinitriles (1). Also, the cyclization of azo derivatives (2d, 2h) with malononitrile in refluxing DMF afforded pyridazine carbonitrile derivatives (3a,b). Moreover, the azo derivatives (2a–m) underwent cyclization on refluxing in DMF to afford pyridazine derivatives (6a–m). All the newly synthesized compounds were characterized by both analytical and spectral analyses. Dyeing performance of the synthesized dyes on polyester fibers has been assessed. Most of the dyes showed good affinity to polyester fibers. No details regarding the synthesis and dyeing performance of such dyes are reported before in the literature.

Picosecond Switchable Azo Dyes.

Azo dyes that combine electron-withdrawing thiazole/benzothiazole heterocycles and electron-donating amino groups within the very same covalent skeleton exhibit relaxation times for their thermal isomerization kinetics within milli- and microsecond timescales at room temperature. Notably, the thermal back reaction of the corresponding benzothiazolium and thiazolium salts occurred much faster, within the picosecond temporal domain. In fact, these new light-sensitive platforms are the first molecular azo derivatives capable of reversible switching between their trans and cis isomers in a subnanosecond timescale under ambient conditions. In addition, theoretical calculations revealed very low activation energies for the isomerization process, in accordance with the fast subnanosecond kinetics that were observed experimentally.

Photocontrol of Supramolecular Azo-Containing Block Copolymer Thin Films during Dip-Coating: Toward Nanoscale Patterned Coatings

Dip-coating allows nanostructured block copolymer (BCP) thin film fabrication in a fast and facile one-step process. It can also be coupled with external controls, such as illumination. Herein, we expose several design principles that enable photocontrol of the nanostructured surface pattern and thickness of supramolecular BCP thin films. This is done using a polystyrene–poly(4-vinylpyridine) (PS-P4VP) BCP and two hydroxy-functionalized small-molecule (SM) azo derivatives that have different photochemical characteristics and that hydrogen bond to the P4VP block. We show how the film preparation concept provides tunability through the chemical structure of the photoactive SM, the relative amount of SM in the dip-coating solution, and the choice of solvent. It was found that the film thickness and SM uptake in the films are increased by illumination when THF is used but are unchanged when toluene is used as solvent, which is attributed to an optical heating effect observable with volatile solvents. The phot...

Medicinal Importance of Azo and Hippuric Acid Derivatives.

In this review, specific therapeutic and medicinal advantages including antiviral, antibacterial, antifungal and antitumor, strategies for drug designing, structure-activity relationship, advances in the syntheses of azo and hippuric acid derivatives of more than 50 compounds have been discussed since 2009-2018. It is found that phenyl-diazenyl azo derivatives and pyridinyl substituted hippuric acid derivatives showed promising antiretroviral potential. The incorporation of azo functionality to the respective quinolones and coumarin moieties and the insertion of thiocarbazone to hippuric acid displayed immense antibacterial activities. While, azo and hippuric acid derivatives of triazole and phenyl species gave maximum fungicidal as well as cytotoxic activities.

Turn-on Fluorescence Chemosensor for Zn2+ Ion Using Salicylate Based Azo Derivatives and their Application in Cell-Bioimaging.

The synthesis and optical studies of salicylate based azo derivatives (DPSAD and IPSAD) are reported. The receptors act as a versatile fluorogenic chemosensor for Zn2+ causing a selective enhancement of fluorescence over other competing cations. The complex formed between receptors and Zn2+ are identified on the basis of absorption and fluorescence titration and further confirmed by ESI-MS. DFT/TD-DFT calculations support the observed optical changes happens only upon complexation with Zn2+ ion. Moreover, receptors are further applied to intracellular sensing and imaging studies. Graphical Abstract Salicylate based azo derivatives (DPSAD and IPSAD) as fluorogenic chemosensor for the detection of Zn2+ ion.

Efficacy of budesonide-loaded mesoporous silica microparticles capped with a bulky azo derivative in rats with TNBS-induced colitis

A colon targeted drug delivery system for inflammatory bowel diseases (IBD), consisting in budesonide loaded mesoporous silica microparticles functionalized with a selective azo-molecular gate (M-Bud), has been evaluated for in vivo efficacy. Experimental colitis in male Wistar rats was induced by rectal instillation of 2,4,6-trinitrobenzenesulfonic acid (TNBS). M-Bud was orally administered to the rats as a suspension in water. Colon/body weight ratio, clinical activity score, and histological evaluation were used as inflammatory indices to measure the performance of the microparticles. The formulation was compared with a suspension prepared from the commercial drug Entocord®. Statistical analyses of all scores indicate that the controlled release of budesonide in colon from M-Bud showed efficacy similar to that of Entocord in the healing of induced colitis in rats.

Uses of 4,4-dicyano-3-phenyl-but-3-enoic acid phenylamide for the synthesis of new compounds: antimicrobial and textile finishing evaluations

PurposeThis work aims to synthesize a series of novel acyclic and/or heterocyclic systems, as precursors for dyes with potential antimicrobial activity that could be used for simultaneous dyeing and antimicrobial textile finishing. Thus, a series of novel pyridine, thiophene and pyrazolo[3,4-b]pyridine derivatives were synthesized, and their antimicrobial and textile finishing properties were studied and evaluated.Design/methodology/approachThe synthesis, structure elucidation and antimicrobial activities of the newly synthesized compounds based on 4,4-dicyano-3-phenyl-but-3-enoic acid phenylamide (1) were demonstrated. The minimal inhibitory concentration in μg/mL of the compounds showed significant antimicrobial activity against most of the tested organisms. On the other hand, their spectral characteristics and fastness properties were measured and evaluated. Antimicrobial activities of the dyed fabrics in terms of inhibition zones (mm) were measured and evaluated.FindingsA series of novel heterocyclic compounds (Schemes 1-3) were synthesized based on starting material (1). Compounds (1), 2, 4a, 8a and 9c exhibited comparable or even higher antibacterial activities than the selected standards (ampicillin), while compounds 2, 3c, 3d, 4a and 8b revealed higher antifungal activities than the selected standard (cycloheximide). On the other hand, some dyes showed high antimicrobial evaluation on the dyed fabrics (nylon 66, acetate and polyester) expressed as size (mm) of inhibition zones (Tables I-IV).Practical implicationsResults revealed that many hydrazo and azo derivatives were synthesized from some pyridines and thiophenes. The antimicrobial evaluation and textile finishing of the newly synthesized products revealed significant and potent values of antimicrobial activity.Originality/valueAll the synthesized compounds were novel and most of them exhibited higher antimicrobial activities than the selected standards antibiotics, thus are valuable for simultaneous dyeing and antimicrobial functional finishing of textile fabrics.