Effect of alkyl chains on luminescence properties with 3-hydroxy-2-naphthoate esters

•Four 3-hydroxy-2-naphthoate esters have been obtained.•Their crystal structures were characterized by single crystal X–ray diffraction.•The luminescence properties can be mediated by the substituted alkyl chain.•The emission maxima are proportional to the alkyl chain length.•The order of the maximal peaks is in an accordance with that of C···H/H···C interactions.