LAUSR

Abstract Two heterofunctional azo reactive dyes (R1 & R2) containing both sulphatoethylsulphone and triazine as chromophoric group were computationally designed having improved dyeing and fastness properties. The designed dyes were synthesized via condensation and diazotization reaction. The spectrophotometer, FT-IR and mass spectrometry were used for the structure elucidation of synthesized dyes. The geometries of designed dyes R1 and R2 were optimized without imposing any constraint with B3LYP and CAM-B3LYP at 6-31G (d,p) under the frame work of density functional theory. Exhaust and pad methods were used for the application of the azo dyes on cotton fabric at different dyeing conditions to assess their colorimetric properties and results were compared with the commercial reactive red 195 dye which were in good agreement. Reactive red 195 was used as standard because of structural similarity with these new azo dyes. Exhaustion, fixation parameters and fastness properties of these dyes have been evaluated to define their efficiency and these properties were found comparable with market available dyes. So these dyes are recommended to use for cellulosic fabric dyeing commercially.