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Electronic Structures and Spectral Properties of 4-Thiophene-1,8-Naphthalimide Derivatives

The molecular geometries, frontier molecular orbital properties, absorption and emission properties of seven 4-thiophene-1,8-naphthalimide derivatives are studied. The ground state optimized structures are obtained by density functional theory (DFT). The lowest singlet states are studied with the configuration interaction singles (CIS) approach. The transition energies of absorption and emission are obtained using time-dependent density functional theory (TD-DFT). It was found that, the 1,8-naphthalimide derivatives with an electron-donating group on the thiophene ring have enhanced fluorescence properties. Our calculations are in good agreement with the experiment results.