Relationship between structure and property of novel reactive yellow dyes containing fluoro-triazine bifunctional groups

Three bi-functional reactive yellow dyes containing fluoro-triazinyl groups,which were based on 2-aminonaphthalene-1,3,6-trisulfonic acid as the diazo components and m-urido-aniline as the azo components,have been studied.Their UV-Vis absorption spectra,dyeing performance parameters and wet fastness were evaluated,and compared with reactive yellow dye C.I.176 with similar structure.The relationship between dye structures and their dyeing properties was investigated.It showed that because of the electrophilic and easy leaving properties of fluorine atom,fluoro-triazinyl reactive dye reacts with fibers much faster than the corresponding chloro-triazinyl reactive dye.Different substituent groups on triazinyl ring can affect the planar and linear structure of molecules,this leads to the change of performance parameters of dyes.In addition,the effect of different substituent groups in the dye precursor on spectrum follows the rule of micro-perturbation MO theory concerning chromophore.