842-07-9Relevant academic research and scientific papers
Preparation and antibacterial activity of mixed ligand complexes of Co(II), Ni(II), Cu(II) and Cd(II) derived from 1-phenylazo-2-naphthol and salicylaldehyde
Sharif,El-Tajoury,Elamari
, p. 43 - 48 (2011)
The mixed ligand complexes of Co(II), Ni(II), Cu(II) and Cd(II) have been synthesized by using 1-phenylazo-2-naphthol as primary ligand and salicylaldehyde as secondary ligand. All the prepared complexes were identified and confirmed by elemental analyses (C, H and N), molar conductance measurements, infrared, electronic absorption and electron paramagnetic resonance. The elemental analysis data suggest that the stoichiometry of the complexes to be 1:1:1[M: L1: L2] ratio. The molar conductance measurements of the complexes indicate their non-electrolytic nature. The infrared spectral data showed the coordination sites of the free ligand with the central metal ion. The electronic absorption spectral data revealed the existence of an octahedral geometry for Co(II) and Cd(II) complexes and a square planar geometry for Ni(II) and Cu(II) complexes. The electron paramagnetic resonance spectra of the Co(II) and Cu(II) complexes showed the existence a paramagnetic phenomenon and supported their geometrical structures which confirmed by the electronic absorption spectra. The ligands and mixed ligand complexes have been tested on antibacterial activity against three strains of pathogenic bacteria such as Escherichia coli, Staphylococcus aureus and Pseudomonas aeruginosa.
Relative strength of the intramolecular hydrogen bonding in 1-phenylazo-naphthalen-2-ol and 1-phenyliminomethyl-naphtahlen-2-ol
Nedeltcheva, Daniela,Antonov, Liudmil
, p. 274 - 281 (2009)
The relative strength of the intramolecular hydrogen bonding (IHB) in the title compounds has been investigated by means of ab initio quantum chemical calculations, UV-Vis spectral study and linear solvation energy relationship analysis (LSER) of the obtained tautomeric constants. It has been found that in acetone (and in all used solvents with substantial proton acceptor abilities) the tautomeric constant in the azonaphthol compound is lower than could be expected. The fact is explained with the breakage of the IHB and the coexistence of closed and open enol tautomers. Copyright
A CONTINUOUS PROCESS FOR THE SYNTHESIS OF AZO DYES INVOLVING IN-SITU GENERATION OF DIAZONIUM SALTS
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Paragraph 0056, (2021/05/21)
The present disclosure provides a continuous process for the synthesis coupled compounds of diazonium salts including azo dyes involving in-situ generation of diazonium salts. It further discloses a set up to carry out the process for the synthesis of coupled compounds of diazonium salts.
One-pot synthesis of azo compounds in the absence of acidic or alkaline additives
Cheng, Xin-Wang,Duan, Pan,Liu, Ting-Ting,Yan, Jiao-Zhao,Zeng, Yao-Fu
, p. 486 - 490 (2020/10/22)
A one-pot method for the synthesis of azo compounds by the reaction of β-naphthol with aryl amines using t-BuONO as the nitrosonium source in DCM at room temperature was developed. This method features mild reaction conditions, a simple experimental procedure, and is free of acidic or alkaline additives.
A quantitative one-pot synthesis method for industrial azo pigments with recyclable wastewater
Feng, Guangyuan,Zhu, Meiling,Liu, Lei,Li, Chunbao
supporting information, p. 1769 - 1776 (2019/04/08)
Most industrial azo pigments are synthesized by diazotization in one pot and then coupling in another. This two-pot process has been transformed into a one-pot method by adding granular PTFE (polytetrafluoroethylene) to a mechanically agitated aqueous mixture of NaNO2, HCl, a diazo component and a coupling component. This method avoids the step of using a base or a surfactant to dissolve the coupling component. The reactions were fast and quantitative. The granular PTFE, wastewater and excess HCl were then reused 11 times without deteriorating the reaction rate and product purity. Altogether, 22 industrial pigments and 3 azo compounds were synthesized and the reaction can produce up to 22.7 g of product in the laboratory. Some reactions require less than 2 equiv. of HCl and a mechanism explaining this is proposed. In addition, an o-nitro group effect is advanced to explain the differences in coupling reaction rates for o-, m- and p-nitroaniline.
Unusual fluorescence of: O-phenylazonaphthol derivatives with aggregation-induced emission and their use in two-photon cell imaging
Yoon, Yeoju,Jo, Seonyoung,Park, Sang Jun,Kim, Hwan Myung,Kim, Dongwook,Lee, Taek Seung
supporting information, p. 6747 - 6750 (2019/06/17)
o-Phenylazonaphthol (o-PAN) derivatives including 6-bromo-1-((4-bromophenyl)diazenyl)naphthalen-2-ol (AN-Br-OH) and 1-phenylazo-2-naphthol (AN-OH, known as Sudan I (Color Index 12055)) were synthesized to investigate their fluorogenic behaviors, in which their aggregated-induced emission (AIE) is reported. The o-PANs showed a two-photon absorption. The protection of hydroxyl groups in o-PANs was used for fluorescence imaging of esterase-expressed HepG2 cells, which is potentially suitable for sensing and two-photon cell imaging applications.
Continuous flow solvent free organic synthesis involving solids (reactants/products) using a screw reactor
Sharma, Brijesh M.,Atapalkar, Ranjit S.,Kulkarni, Amol A.
supporting information, p. 5639 - 5646 (2019/10/22)
Here we report for the first-time various organic transformations such as aldol condensation, oxidation, nucleophilic substitutions, protection, acylations and coupling reactions using a mechanochemical approach at a controlled temperature using a single synthesis platform. Almost minimal solvents or solvent-free conditions are used, making it a very efficient and clean synthesis of various products. A jacketed screw reactor when operated at different temperatures (0 °C to 160 °C) and over a range of rotation speeds for changing the residence time (15 s-300 s) helped to achieve maximum conversion. This approach is also extended to the synthesis using substrates having different substitutions, heterocycles and steric hindrance.
Electronic and spectral studies of some five coordinate complexes of copper (II)
Kumar, Birendra,Rani, Rekha,Prasad, Dayanand,Singh, Praveen Kumar,Kumar, Amit,Sharma, Shivadhar
, p. 1463 - 1468 (2019/09/06)
1-phenylazo-2-nephthol has been synthesized and used for complexation with Cu(II) metal ion along with pyridine, α-picoline, β-picoline, γ-picoline and water as secondary ligands. On the basis of elemental analysis and molar conductivity complexes were formulated as CuL2X [Where L is the prime ligand i.e 1-phenyl-azo-2-nephthol and X is the secondary ligand i.e. pyridine, α-picoline, β-picoline, γ-picoline and H2O.] The magnetic moment of these complexes (1.80-1.83 BM) indicates that these complexes are magnetically dilute. The appearance of 3 bands in the electronic spectra of complexes rules out the trigonal bipyramidal (D3h) symmetry arround Cu(II) ion in these complexes rather the electronic spectra favours square pyramidal (C4V) symmetry of these five coordinate complexes. The highest value of 10Dq clearly indicates the greater coordinating ability of α-picoline than pyridine, β-picoline and γ-picoline.
Method used for synthesizing azo compound using solid particle one kettle method
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Paragraph 0107; 0108; 0109, (2019/01/07)
The invention relates to a method used for synthesizing an azo compound using solid particle one kettle method. The method comprises following steps: solid particles are introduced into a reaction container, an inorganic acid, an aromatic primary amine, sodium nitrite, water, and a coupling component are added, mechanism stirring is carried out, when the reaction is monitored to be finished, filtering and rinsing are carried out, and the obtained filter cake is a finished product; or the solid particles are introduced into the reaction container, the inorganic acid, the aromatic primary amine,sodium nitrite, and water are added, mechanical stirring is carried out, after complete conversion of the aromatic primary amine, the coupling component is added, mechanical stirring is carried out,when the reaction is monitored to be finished, filtering and rinsing are carried out, and the obtained filter cake is a finished product. The solid particles are preferably selected from polytetrafluoroethylene particles, haw seeds, or stainless steel sand. The solid particles are added into the reaction system to promote reaction, no pre-heating or alkali adding dissolving of diazo components orthe coupling component is needed; most reaction is finished in 1h; reaction time is short; product quality is high; and reaction filtrate and excess inorganic acid can be recycled for a plurality of times.
A concept for stimulated proton transfer in 1-(phenyldiazenyl)naphthalen-2-ols
Hristova,Deneva,Pittelkow,Crochet,Kamounah,Fromm,Hansen,Antonov
, p. 91 - 99 (2018/11/23)
A series of aryl azo derivatives of naphthols (1–3) were studied by means of UV–Vis and NMR spectroscopy in different solvents as well as by quantum chemical calculations and X-ray analysis. Previous studies have shown that Sudan I (1) exists as a tautomeric mixture. The effect of the solvents is minimized by the existing intramolecular hydrogen bond. Therefore, the influence on the tautomeric state in structurally modified 1 has been investigated. Structure 2 contains an additional OH-group, which deprotonates easily and affects the position of the tautomeric equilibrium by changing the electronic properties of the substituent. The implementation of a sidearm in 3 creates a condition for competition between the nitrogen from the azo group and from the piperidine unit for the tautomeric proton. In this case the use of acid as a stimulus for controlling the tautomeric process was achieved.
