Photophysics of 3-Substituted Benzanthrones:  Substituent and Solvent Control of Intersystem Crossing

Abstract

The solvent dependence of absorption and fluorescence spectra, fluorescence lifetimes (τ Fl ), and quantum yields (q Fl ) of various 3-substituted benzanthrone derivatives have been investigated. A consistent correlation between fluorescence quantum yield and emitting state energy has been found that holds for all 6 derivatives in 11 solvents. The experimental data together with the results of semiempirical quantum chemical calculations indicate that the main quenching channel of the fluorescent S 1 (π,π*) excited state is intersystem crossing to an upper (n,π*) triplet state, T N . The rate constant and efficiency of intersystem crossing between these two states are strongly influenced by the substituent and by the solvent polarity, as both modulate the singlet state energy and the S 1 -T N energy gap. The rate constant of direct S 1 f T 1 intersystem crossing is small in most systems but appears to increase with a decrease in the energy of the S 1 state.

Luminescence and structural properties of thermally evaporated benzanthrone dyes thin films

“…The polarization occurring upon irradi− ation results from the electron donor−acceptor interaction between the electron−donating substituents at the 3−position and the electron−accepting carbonyl group of the chromo− phorous system [11,12].…”

The synthesis of N-derivatives of 3-aminoperylene and their absorption and fluorescence properties

“…2); the shift is not large and increases with solvent polarity (Table 1). 1,4-Dioxane (DO) behaves like a more polar solvent even though its dielectric constant (2.22) is smaller than that of dibutyl ether (DBE) (3.08); it could be caused by quadrupole moments that contribute significantly to solvation (similar behaviour was observed for toluene and chlorbenzene) [3].…”

“…In previous papers [2,3] we reported on the synthesis and solvent effect on absorption and fluorescence spectra, fluorescence lifetime and fluorescence quantum yield of N-triazinyl derivatives of 3-aminobenzanthrone. Recently, we have described spectral and photophysical characteristics of N-triazinyl derivatives of 1-and 2-aminopyrenes [4].…”

The synthesis and fluorescence of N-substituted 1- and 2-aminopyrenes

“…In a previous paper [4], we reported on the synthesis, absorption and fluorescence spectra of N-(1,3,5-triazine-2-yl)-3-aminobenzanthrone derivatives. More recently, we have reported on a solvent dependence of absorption and fluorescence spectra, fluorescence lifetimes and fluorescence quantum yields of various 3-substituted benzanthrone derivatives [5]. The experimental data together with the results of semi-empirical quantum chemical calculations indicate that the main channel of the fluorescent S 1 (p,p*) excited state of studied compounds is an intersystem crossing to an upper (n,p*) triplet state.…”