A 3x14 matrix of substituted N-aryl-1,8-naphthalimides was synthesized for the evaluation and discovery of dual fluorescence. Because of their unique photophysical properties, these dual fluorescent systems represent an exception to the widely studied TICT (Twisted Internal Charge Transfer) fluorescent dyes or tautomeric benzofluorescein class of two-color dyes. The small library was designed to investigate the effects of heterocycles, particularly

-excessive and

-deficient systems. Of the forty-two investigated compounds, five displayed well-resolved two-color emission in solvents as non-polar as hexane. Based on the trends in fluorescence lmax and quantum yield, a new model is proposed which potentially predicts LW and SW emission for these systems. In addition, this model provides key design features for the synthesis of new dual fluorescent species.