55252-43-2Relevant articles and documents
Trapping of a reaction intermediate by cyclodextrins
Ye,Tong,D'Souza
, p. 6271 - 6274 (1992)
The formation and decomposition of an intermediate is observed spectrophotometrically in the coupling reaction between p-nitrophenyldiazonium chloride and N,N-dimethylaniline in the presence of β-cyclodextrin. A kinetic analysis of this process is reported.
New Simple Functions To Describe Kinetic and Thermodynamic Effects of Pressure. Application to Z-E Isomerization of 4-(Dimethylamino)-4'-nitroazobenzene and Other Reactions
Asano, Tsutomu,Okada, Toshio
, p. 238 - 243 (1984)
Two simple three-parameter equations are proposed as functions to describe kinetic and thermodynamic effects of pressure.The functions are found to reproduce experimental results more accurately than the most frequently used quadratic equation.The estimat
Reversal of Pressure Effect on Thermal Z-E Isomerization of 4-(Dimethylamino)-4'-nitroazobenzene
Asano, Tsutomu,Okada, Toshio
, p. 695 - 696 (1987)
It has been discovered that the kinetic effect of pressure on Z-E isomerization of 4-(dimethylamino)-4'-nitroazobenzene reverses at about 500 MPa in glycerol triacetate at 25 deg C.At lower pressures, the rate increases with increasing pressure, but at hi
Further Kinetic Evidence for the Competitive Rotational and Inversional Z-E Isomerization of Substituted Azobenzenes
Asano, Tsutomu,Okada, Toshio
, p. 4454 - 4458 (1986)
The first-order rate constant for thermal Z-E isomerization of 4-(dimethylamino)-4'-nitroazobenzene was measured in various solvents at different temperatures and pressures.The temperature dependence of the activation volume was qualitatively different in
Experimental and theoretical studies of azo derivatives in terms of different donors, acceptors and position isomerism: Synthesis, characterization and a combined electronic absorption, electrochemical and DFT study
Mohan A, Keerthi,Purushothaman, Aiswarya,Janardanan, Deepa,Haridas, Karickal R.
, (2021/10/12)
Eight azo derivatives with two donor groups- diphenylamine and N,N-dimethylphenyl, and four acceptor groups - 3-nitrophenyl, 4-nitrophenyl, 4-phenylcarboxylic acid, and 3-phenylcarboxylic acid, were synthesized and characterized using 1H-NMR an
Hole Catalysis as a General Mechanism for Efficient and Wavelength-Independent Z → E Azobenzene Isomerization
Goulet-Hanssens, Alexis,Rietze, Clemens,Titov, Evgenii,Abdullahu, Leonora,Grubert, Lutz,Saalfrank, Peter,Hecht, Stefan
supporting information, p. 1740 - 1755 (2018/06/29)
Whereas the reversible reduction of azobenzenes has been known for decades, their oxidation is destructive and as a result has been notoriously overlooked. Here, we show that a chain reaction leading to quantitative Z → E isomerization can be initiated before reaching the destructive anodic peak potential. This hole-catalyzed pathway is accessible to all azobenzenes, without exception, and offers tremendous advantages over the recently reported reductive, radical-anionic pathway because it allows for convenient chemical initiation without the need for electrochemical setups and in the presence of air. In addition, catalytic amounts of metal-free sensitizers, such as methylene blue, can be used as excited-state electron acceptors, enabling a shift of the excitation wavelength to the far red of the azobenzene absorption (up to 660 nm) and providing quantum yields exceeding unity (up to 200%). Our approach will boost the efficiency and sensitivity of optically dense liquid-crystalline and solid photoswitchable materials. Video Abstract: [Figure presented] Molecular switches are a key ingredient in stimulus-responsive and adaptive materials and devices. Light is among the most attractive stimuli, yet photoswitches often require intense irradiation with high-energy UV light and suffer from inefficient switching as well as fatigue. Thus, the design of robust and efficient photoswitches constitutes an important challenge to boost the sensitivity and energy efficiency of the respective materials and devices. Here, we describe that the isomerization of azobenzene switches from their less stable Z isomer back to the more stable E isomer can be triggered by tiny, i.e., catalytic, amounts of holes caused by chemical, electrochemical, or photochemical oxidation. Our method is generally applicable to the entire family of azobenzene switches, does not require expensive equipment, and allows the reliable and efficient operation of these photoswitches by using red light with quantum efficiencies up to 200%. An efficient and generally applicable method is developed for operating azobenzene molecular switches by using catalytic amounts of holes (via an oxidant) or photons (via a photosensitizer). The pathway allows for indirect Z → E photoisomerization using lower-energy light than required for direct azobenzene excitation and with high quantum yields exceeding unity. The method should help to enhance the sensitivity of photoresponsive materials and devices with high optical density.
New generation of nitrite functionalized star-like polyvinyl imidazolium compound: Application as a nitrosonium source and three dimensional nanocatalyst for the synthesis of azo dyes
Shomali, Ashkan,Valizadeh, Hassan,Noorshargh, Saeideh
, p. 409 - 418 (2017/07/24)
The compounds with three-dimensional and ionic structures have attracted considerable attentions because of their unique characteristics as a drug carrier and catalyst. Star-like poly ionic compounds are a new generation of three-dimensional structures which have both; the exclusive ionic features and three-dimensional structures. Recently, we reported the synthesis of diazonium salts from aniline derivatives using carboxyl and nitrite functionalized graphene quantum dots. Methods: Nitrite-functionalized star-like polyionic (NFSP) compound was synthesized as a new generation of three-dimensional nanocatalyst. Herein, the use of NFSP as an efficient reagent and nanocatalyst for the diazotization of aniline derivatives and subsequent synthesis of azo dyes via the reaction with active phenolates under solvent-free conditions was reported. Results: In order to demonstrate the positive impact of NFSP efficiency, the reaction times and yields of the products were compared with other methods and catalysts which have been reported previously. The brilliant performance of NFSP can be ascribed to multifunctional reagent and also trapping the ingredient within catalyst cavities. Conclusion: A highly effective and cost-effective method has been developed for the preparation of azo dyes. In reported method, new three-dimensional catalyst with highly ionic characteristic and multifunctional nitrosonium source is available. These special features reduced the required amount of catalyst, reaction time and also increased the efficiency of catalyst.
Nano-CuFe2O4-supported sulfonic acid as a novel and recyclable nanomagnetic acid for diazotization of aromatic amines: efficient synthesis of various azo dyes
Nemati, Firouzeh,Elhampour, Ali,Natanzi, Mahshid B.,Sabaqian, Samaneh
, p. 1045 - 1054 (2016/05/02)
Abstract: A novel heterogeneous sulfonic acid functionalized nanomagnetic CuFe2O4 was successfully prepared and characterized by analyzing different obtained data including Fourier transform infrared spectroscopy, X-ray powder diffraction, field emission scanning electron microscopy, energy-dispersive X-ray spectroscopy, thermogravimetric analysis, dynamic light scattering and vibrating sample magnetometer. Then the novel acidic reagent was examined in synthesis of various azo-containing compounds from coupling of aryl diazonium ferrite sulfate salts with aromatic and non-aromatic compounds. The procedure starts by diazotization of aromatic amines with NaNO2 and wet CuFe2O4–SO3H and then coupling reaction of aryl diazonium ferrite sulfate salts with appropriate reagent. The prepared nano-solid acid showed high activity in synthesis of variety of aryl diazonium salts. In addition the as-prepared aryl diazonium ferrite sulfate salts are stable at room temperature for many hours and reacted efficiently in coupling reactions of aryl diazonium salts. All the azo dyes are synthesized in high yields and simple reaction conditions at room temperature. Moreover, the nanomagnetic solid acid was easily recovered from the reaction mixture and reused five runs without significant loss of activity. Graphical Abstract: [Figure not available: see fulltext.]
Convenient and rapid diazotization and diazo coupling reaction via aryl diazonium nanomagnetic sulfate under solvent-free conditions at room temperature
Koukabi, Nadiya,Otokesh, Somayeh,Kolvari, Eskandar,Amoozadeh, Ali
, p. 12 - 17 (2015/10/05)
For the first time, nanomagnetic-supported sulfonic acid is used for conversion of several types of aromatic amine, containing electron-withdrawing groups as well as electron-donating groups to the corresponding azo dyes in excellent yield. The synthesis of these compounds is described by the sequential diazotization-diazo coupling of various aromatic amines with sodium nitrite, nanomagnetic supported sulfonic acid and coupling agents under solvent-free conditions at room temperature. This new method offers several advantages including short reaction time, mild reaction conditions, avoidance of harmful acids, and simple work-up procedure. More importantly, aryldiazonium salts supported on magnetic nanoparticles (aryl diazonium nanomagnetic sulfate) were sufficiently stable to be kept at room temperature in the dry state.
Solvatochromic behavior of dyes with dimethylamino electron-donor and nitro electron-acceptor groups in their molecular structure
De Melo, Carlos E. A.,Nandi, Leandro G.,Domínguez, Moisés,Rezende, Marcos C.,Machado, Vanderlei G.
, p. 250 - 260 (2015/03/31)
Six dyes with N,N-dimethylaminophenyl and 4-nitrophenyl or 2,4-dinitrophenyl groups in their molecular structures were prepared and characterized. These compounds have different conjugated bridges (C-C, C-N, and N-N) connecting the electron-donor and the electron-acceptor groups. All compounds are solvatochromic, with reverse solvatochromism occurring. The solvatochromic band observed in each spectrum for the dyes is due to a π rarr π? transition, of an intramolecular charge transfer nature, which occurs from the electron-donor N,N-dimethylaminophenyl group to the electron-acceptor group in the molecules, which is reinforced by the structures of the compounds optimized by applying density functional theory, which exhibit high planarity. The reverse solvatochromism was explained considering two resonance structures. The benzenoid form is better stabilized in less polar solvents and characterizes the region displaying positive solvatochromism, while the dipolar form is better stabilized in more polar solvents, in the region of negative solvatochromism. The Catalán multiparametric approach was used to study the contribution of solvent acidity, basicity, dipolarity, and polarizability to the solvatochromism exhibited by the compounds. These compounds are good candidates for the investigation of the polarizability and, to a lesser extent, the dipolarity of the medium, with very little interference from specific interactions of the solvent through hydrogen bonding.
