2491-74-9Relevant articles and documents
Cyclodextrin-induced host-guest effects of classically prepared poly(NIPAM) bearing azo-dye end groups
Maatz, Gero,Maciollek, Arkadius,Ritter, Helmut
, p. 1929 - 1935 (2012)
A thermo-, pH- and cyclodextrin-(CD) responsive poly(N-isopropylacrylamide) (PNIPAM), with a N,N-dimethylaminoazobenzene end group was synthesized. Using 3-mercaptopropionic acid as a chain transfer agent, PNIPAM with a well-defined COOH end group was obtained. The acid end group was transferred to the corresponding acid chloride and then functionalized with N,Ndimethyl[4-(4'- aminophenylazo)phenyl]amine. This dye-end-group-labeled polymer showed acidochromic effects, depending on the pH and the presence of randomly methylated β-cyclodextrin (RAMEB-CD). Also higher cloud-point values for the lower critical solution temperature (LCST) in the presence of RAMEB-CD were observed. Additionally, this azo-dye-end-group-labeled polymer was complexed with hyperbranched polyglycerol (HPG) decorated with β-CD to generate hedgehog-like superstructures.
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.]
Carboxyl and nitrite functionalized graphene quantum dots as a highly active reagent and catalyst for rapid diazotization reaction and synthesis of azo-dyes under solvent-free conditions
Valizadeh, Hassan,Shomali, Ashkan,Nourshargh, Saideh,Mohammad-Rezaei, Rahim
, p. 522 - 528 (2015/03/18)
Carboxyl and nitrite functionalized graphene quantum dots was prepared from carboxyl and hydroxyl functionalized graphene quantum dots using NaNO2 in the absence of mineral acids. This functional group conversion was confirmed by FT-IR spectroscopy, photoluminescence and X-ray diffraction. The carboxyl and nitrite functionalized graphene quantum dots was used as an effective nitrosonium ion source and reusable catalyst for the efficient diazotization of a variety of arylamines without using any additional acid. Subsequent azo-coupling of these freshly prepared diazonium salts with a range of active aromatic compounds led to the requisite azo-dyes in excellent yields in very short reaction times with a simple experimental procedure.
