SPECTROSCOPIC CHARACTERIZATION AND LANGMUIR-BLODGETT MONOLAYERS OF N,N'-UNSYMMETRICAL DIALKYL-3,4/9,10-PERYLENEBIS(DICARBOXIMIDE)S

The spectroscopic characterization of N-pentyl-N'-R-unsymmetrical dialkyl-3,4:9,10-perylenebis(dicarboximide)s (R = CH3, C2H, and C3H7) is reported. Langmuir monolayers of all three non-amphiphilic molecules were successfully prepared and transferred to solid substrates. The absorption and fluorescence spectra of solutions and Langumuir-Blodgett (LB) films were studied. Vibrational fundamental frequencies were observed using surface-enhanced resonance Raman scattering and transmission and reflection-absorption Fourier transform infrared spectroscopy. The formation of aggregates in the ground and excited states (excimer formation) is also discussed.