سال انتشار: ۱۳۸۷

محل انتشار: همایش بین المللی ژئولیت ایران

تعداد صفحات: ۵

نویسنده(ها):

a Teimouri –
a Najafi Chermahini – Department of Chemistry, Yasuj University,
h.d Dabbagh – Department of Chemistry, Isfahan University of Technology,

چکیده:

Azo dyes are compounds that contain azo groups linked to methine or aromatic sp2-hybridized C-atoms.
The formation of diazotizing reagent starts with protonation of nitrous acid under strongly acidic conditions,
and azo coupling carried out at low temperature in the presence of nucleophilic coupling components, the
reactivity of a nucleophilic substrate increases with increasing basicity phenolates and amines [1]. These
conventional acidebase catalyzed processes are effective for the near quantitative formation of the desired
products. But the main limitation of such synthetic processes is their environmental incompatibility. The
acidic and basic effluents from the laboratory and industry produce permanent damage to the environment
and disturb the ecological balance [2]. In recent years, clay based catalysts are reported to be effective for
performing many of the acidebase catalyzed organic reactions in a better, environmentally benign manner [3,
4]. Nowadays more and more heterogeneous Bronsted acids, e.g. zeolites are utilized, the excellent catalytic
abilities are due to the presence of Bronsted and Lewis acid centers in the zeolite structure [5]. Because of its
high protonic acidity and unique shape-selective behavior, ZSM HZSM-5, HY, and H-beta have been shown
to be a highly active and stable catalyst for reactions [6].
As part of our ongoing research program for exploring