title: Spectroscopy and photophysics of iso- and alloxazines: experimental and theoretical study.
abstract: We present a systematic study of the effect of methyl substitution on iso- and alloxazines in acetonitrile solutions. Substitution patterns have profound effects on both spectral and photophysical properties, with fluorescence quantum yields varying by more than an order of magnitude. TD-DFT calculation were used for the first time to correlate electronic structure changes with the substitution patterns, with good agreement between calculated and theoretical band positions and oscillator strengths. Both n-pi* and pi-pi* states in these compounds are predicted, with the oscillator strengths indicating that only the pi-pi* states should be observable in the absorption spectra. Substitution patterns are shown to be responsible for energy order inversion between these states.
authors.affiliation: Faculty of Commodity Science, Poznań University of Economics, Poznań, Poland. ewa.sikorska@ae.poznan.pl
authors.forename: Ewa
authors.initials: E
authors.lastname: Sikorska
authors.forename: Igor V
authors.initials: IV
authors.lastname: Khmelinskii
authors.forename: David R
authors.initials: DR
authors.lastname: Worrall
authors.forename: Jacek
authors.initials: J
authors.lastname: Koput
authors.forename: Marek
authors.initials: M
authors.lastname: Sikorski