Photoactive thin films based on benzoxazole derivatives

In this work it is presented a photophysical study of thin films based on excited-state intermolecular proton transfer dyes 2-(4'amino-2'-hydroxyphenyl)benzoxazole (AHPBO) and 2-(4'aminophenyl)benzoxazole (APBO). The studied thin films were characterized by Raman Spectroscopy, Atomic Force Microscopy, as well as Photoluminescence and UV-Vis absorption spectroscopies. In addition, theoretical calculations were applied using Gaussian09 software to obtain vibrational frequencies, corresponding vibrational assignments and its correlation with experimentally obtained by Raman spectra. The ESIPT mechanism showed to play a fundamental role on the photophysics of the AHPBO in despite of the APBO where only a locally excited specie takes place in the excited state.