Photophysical and photochemical properties of anthraquinones: A DFT study

in the present work, we investigated the photophysical and photosensitive properties and further explored the substituent effects on these properties of a series of anthraquinones by means of theoretical calculations. It is revealed that comparing with the parent 9,10-anthraquinone (AQ), the substitutents red-shifted the absorption spectra and lowered the E-TI of anthraquinones considerably. Moreover, the present results also provide some deeper insights into the photosensitization mechanisms of anthraquinones, that is, although anthraquinones can photo-generate O-1(2) through direct energy transfer in both non-polar and polar solvents, they give birth to O-2(center dot-) through electron transfer only in polar solvents, and it is the anthraquinones anions (generated from autoionization) that are responsible for the O-2(center dot-) generation. (C) 2008 Published by Elsevier B.V.