Spectroscopy of Acridines and Xanthones

The family of acridines and xanthones represent important groups of aza-aromatic compounds of interest in different areas. Acridine was discovered to be an important agent with interest in the field of photodynamic therapy, among other applications. The change on the npi* to pipi* nature of the fluorescing state upon increasing of the solvent polarity can be successfully explained by the ab initio results. On the other hand, xanthone derivatives such as thioxanthone are nowadays under intense research because of their particular spectroscopical properties, such as the lack of a expected solvatochromic shift which puzzles spectroscopists.