Solvent Dependent Energy Transfer of N-bridged Naphthalimide-Bisindolymaleimide Fluorescent Dyes

Abstract

Double build-in chromophores, naphthalimide (NIM) and bisindolymaleimide (BIM), were synthesized and characterized. Absorption and emission properties of double chromophores dye were fully investigated in various solvents. The priority of through bond energy transfer (TBET) to NTM or BIM is solvent dependent. There appears large different emission wavelength change in CHCl₃ and DMF with alkyl attached to BIM. However, the product of cyclohexyl substitution leads to a different emission behavior, which is non-sensitivity to solvent polarity. Quantum chemical calculation for the molecular orbital reveals that intramolecular charge transfer (ICT) is the key factor for their different opto-electronic properties.

Keywords:

• Biindolymaleimide
• ICT
• naphthalimide
• solvent dependent
• TBET

Acknowledgments

This work was supported by the National Natural Science Foundation of China (grant no. 21072048), the PIRTUHP (grant no. 2012IRTSTHN006), PCSIRT (grant no. IRT1061), and by the Basic Science Research Program through the National Research Foundation of Korea (NRF) funded by the Ministry of Education, Science and Technology (grant no. 20120008198).