- 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
-
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.
- Shomali, Ashkan,Valizadeh, Hassan,Noorshargh, Saeideh
-
p. 409 - 418
(2017/07/24)
-
- Synthesis of a nitrite functionalized star-like poly ionic compound as a highly efficient nitrosonium source and catalyst for the diazotization of anilines and subsequent facile synthesis of azo dyes under solvent-free conditions
-
Nitrite functionalized star-like poly ionic (NFSPI) compound was synthesized and used as a highly efficient nitrosonium source and catalyst for the conversion of aniline derivatives to diazonium salts. Azo dyes were prepared via in situ azo-coupling reaction of these diazoniums with active aromatic compounds under solvent-free conditions in very short reaction time in excellent yields. NFSPI plays dual role as a three-dimensional nitrosonium source and catalyst because of its poly ionic characteristic. The isolated products were confirmed with FT-IR spectrum, 1H-NMR, 13C-NMR spectroscopy and CHNSO analysis. The structure of heterogeneous reagent and catalyst was confirmed by FT-IR spectrum, SEM images, EDX and CHNSO analysis. Yields and reaction times for the synthesis of a variety of products via this procedure were compared with reported values in literature.
- Valizadeh, Hassan,Shomali, Ashkan,Ghorbani, Jalal,Noorshargh, Saeideh
-
-
- COMPOSITION FOR DYEING KERATIN FIBRES, COMPRISING A CATIONIC DIAZO DIRECT DYE CONTAINING A 2-IMIDAZOLIUM UNIT
-
The present invention relates to a composition for dyeing keratin fibres, comprising at least one cationic diazo direct dye chosen from the compounds of formula (I) or (II) below, the mesomeric forms thereof, and also the acid-addition salts thereof and s
- -
-
Page/Page column 47-48
(2008/06/13)
-
- THERMAL ISOMERIZATION OF AZOBENZENES. III. SUBSTITUENT, SOLVENT, AND PRESSURE EFFECTS ON THE THERMAL ISOMERIZATION OF PUSH-PULL AZOBENZENES.
-
The substituent, solvent, and pressure effects on the rate of the thermal cis-to-trans isomerization of 4-dimethylamino-4 prime -nitroazobenzene (NDAAB) derivatives have been studied. 2-Methyl- and 2 prime -chloro-NDAAB isomerize faster than NDAAB, and 2 prime -methyl- and 2-chloro-NDAAB isomerize slower than NDAAB. For 2,2 prime -dimethyl- and 2,2 prime -dichloro-NDAAB, the rates are between those of the monosubstituted ones. These findings are very similar to those for 4-(dimethylamino)azobenzene (DAAB) derivatives, and no fundamental difference in the kinetic-substituent effects was observed between NDAAB and DAAB. The volume of activation, which is of a negative value, varies remarkably from solvent to solvent and from substituent to substituent; its magnitude increases generally with an increase in the solvent polarity.
- Nishimura,Kosako,Sueishi
-
p. 1617 - 1625
(2007/10/02)
-