Synthesis and photochemical properties of novel 4-diarylamine-1,8-naphthalimide derivatives

Several novel, diarylamine-substituted 1,8-naphthalimide derivatives were synthesized and characterized by FT-IR, 1H, 13C NMR, mass spectra and elemental analyses. The asymmetry inherent in the compounds prevented them from crystallizing and high thermal stability compounds were formed, with glass transition temperatures up to 105 °C. The UV–vis absorption and photoluminescent (PL) spectra of the compounds in n-hexane, tetrahydrofuran (THF) and CH2Cl2 were investigated. The lowest absorption band of the naphthalimide derivatives centered at ≈450 nm was assigned to charge-transfer transition with an emission at 494–506 nm in nonpolar solvents such as n-hexane and at 578–624 nm in polar solvents such as THF and CH2Cl2.