this research is an attempt to measure the effect of alkyl tail on the visible spectra and order parameters s of some azo n-ester-1,8-naphthalimide(anen) disperse dyestuff. for the first time, the visible absorption spectra of two azo n-ester-1,8-naphthalimide(anen) dyes with identical molecular size and diverse alkyl tails were obtained in liquids and liquid crystalline solvent. ordinary organ...