Spectroscopy and photophysics of 6,7-dimethyl-alloxazine: experimental and theoretical study

Molecular structure, ground state and triplet–triplet electronic absorption spectra were predicted for the title compound using the timedependent density functional theory calculations. These predictions reproduce well the experimental results, making allowance for the contribution of the solvent interactions, disregarded in the present calculations. Spectral and photophysical properties were compared to those of other alloxazine derivatives, and rationalized based on the proximity effect theory. Triplet quenching rate by oxygen was determined, along with the resulting singlet oxygen yields. q 2004 Elsevier B.V. All rights reserved.