Abstract
A number of red to violet thienyl-2-azo and thienyl-5-azo disperse dyes were prepared using Gewald's methodology. Structural characterization of these novel dyes was carried out using IR, NMR and mass spectroscopy. UV–visible studies of these azo dyes in a number of polar solvents showed a considerable difference in the
λ
max. The introduction of various substituents to these azo dyes as well as the polarity of solvents resulted in absorption in the visible region ranging from 461 to 555
nm.