1435-60-5Relevant articles and documents
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van Haverbeke,Herman
, p. 932 (1979)
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Ionic liquid 1-(3-trimethoxysilylpropyl)-3-methylimidazolium nitrite as a new reagent for the efficient diazotization of aniline derivatives and in situ synthesis of azo dyes
Valizadeh,Amiri,Shomali,Hosseinzadeh
, p. 495 - 501 (2011)
A new ionic liquid 1-(3-trimethoxysilylpropyl)-3-methylimidazolium nitrite was synthesized. This ionic liquid was used as a convenient nitrosonium source in diazotization of arylamines into their corresponding diazonium salts which were converted into their related azo dyes via the in situ azo-coupling with aniline derivatives or phenolic compounds. The diazotization of anilines in this ionic liquid and subsequent azo-coupling generated the related azo dyes in good to excellent yields at 0-5 °C in short reaction times via a simple experimental procedure.
Stimuli responsive materials supported by orthogonal hydrogen and halogen bonding or i···alkene interaction
Frangville, Pierre,Gelbcke, Michel,Kumar, Shiv,Meyer, Franck,Van Hecke, Kristof
, (2021/12/24)
Smart materials represent an elegant class of (macro)-molecules endowed with the ability to react to chemical/physical changes in the environment. Herein, we prepared new photo responsive azobenzenes possessing halogen bond donor groups. The X-ray structures of two molecules highlight supramolecular organizations governed by unusual noncovalent bonds. In azo dye I-azo-NO2, the nitro group is engaged in orthogonal H···O···I halogen and hydrogen bonding, linking the units in parallel undulating chains. As far as compound I–azo–NH–MMA is concerned, a non-centrosymmetric pattern is formed due to a very rare I···π interaction involving the alkene group supplemented by hydrogen bonds. The Cambridge Structural Database contains only four structures showing the same I···CH2=C contact. For all compounds, an19F-NMR spectroscopic analysis confirms the formation of halogen bonds in solution through a recognition process with chloride anion, and the reversible photo-responsiveness is demonstrated upon exposing a solution to UV light irradiation. Finally, the intermediate I–azo–NH2 also shows a pronounced color change due to pH variation. These azobenzenes are thereby attractive building blocks to design future multi-stimuli responsive materials for highly functional devices.
Photoisomerization and Mesophase Formation in Azo-Ionic Liquids
Renier, Olivier,Bousrez, Guillaume,Stappert, Kathrin,Wilk-Kozubek, Magdalena,Adranno, Brando,Pei, Hanwen,Spielberg, Eike T.,Smetana, Volodymyr,Mudring, Anja-Verena
, p. 214 - 225 (2019/12/24)
Ionic liquids present a versatile, highly tunable class of soft functional materials. Aside from being low melting salts, they can be endowed with additional functionalities. In N-alkylimidazolium halides, which are a prominent class of ionic liquids (ILs), the imidazolium cation was linked via an ether-bridge to an azobenzene unit in order to obtain photoresponsive materials through photoinduced trans-cis isomerization. The azobenzene unit, in turn, was modified with electron-donating or -withdrawing groups such as methyl-, tert-butyl-, methoxy-, N,N-dimethylamino, and nitro groups to study their influence on the photoisomerization and phase behavior. Endowing the imidazolium additionally with a long alkyl chain allows the materials to potentially form liquid crystalline (LC) mesophases before melting into the isotropic liquid. All studied compounds qualify as ionic liquids, and all, except for the nitro-compound, show the formation of smectic mesophases melting to the isotropic liquid. The compounds with the bulkiest aliphatic substituent, the tert-butyl, shows the lowest melting point, the largest mesophase window, and an efficient photochemical trans-cis conversion (>90%). In summary, by tuning sterically and electronically the cationic part of ILs, a photoswitchable room temperature liquid crystal could be developed and design guidelines for photoresponsive ionic liquids could be obtained.
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.]
