Spectroscopic and electrochemical studies of N, N′-bis(decamethylcarboxylic)-3,4,9,10-perylene-bis(dicarboxyimide)

Abstract

The vibrational and electronic characterization of N, N′-bis(decamethylcarboxylic)-3,4,9,10-perylene-bis(dicarboxyimide) prepared by the Langmuir-Blodgett (LB) technique was accomplished, and the average molecular orientation in LB films was calculated from the transmission and RAIRS data. It was found that the short and long chromophore axes are tilted to the perpendicular by about 70° and 28°, respectively. Using electronic spectra together with steady state fluorescence, it was concluded that the packing behavior of perylene tetracarboxylic diimide is mainly determined by II-II aromatic interactions. The electrochemical measurements show the presence of a non-negligible amount of pinhole defects in the prepared films. Monolayers of arachidic acid were used as spacer layers on silver island films, and resonance Raman scattering from the molecules was studied as a function of their spacing from the rough silver layer. A long range SERRS effect with an enhancement dropping off between 11 and 13 nm was obtained.