T. Kircher et Hg. Lohmannsroben, Photoinduced charge recombination reactions of a perylene dye in acetonitrile, PCCP PHYS C, 1(17), 1999, pp. 3987-3992
In the present study, the photophysical properties of the perylene dye PBI
[N,N'-bis(1-hexylheptyl)-3,4:9,10-perylenebis(dicarboximide)] and the quenc
hing of PBI fluorescence by organic quencher molecules in acetonitrile was
investigated with stationary and time-resolved fluorescence and absorption
measurements. On the basis of a simplified reaction scheme, a comprehensive
analysis of the fluorescence quenching process was achieved for 8 PBI-quen
cher molecular pairs for which the formation of free PBI ions was observed.
It is notable that both the anionic and cationic species ((PBI-)-P-2, (PBI
+)-P-2) were detected as primary products of the intermolecular ElT process
es. Together with other data from our group and by Mataga et al. (Chem. Phy
s., 1988, 127, 249) an evaluation of the results within the framework of th
e Marcus theory of non-adiabatic electron transfer was performed. It was fo
und that with an overall variation of the standard free energy changes for
the charge recombination (CR) reaction to the PBI ground (Delta G(CR)(G)) a
nd triplet states (Delta G(CR)(T)) of more than 2 eV the CR reaction rate c
onstants cover the whole energetic range of the non-adiabatic electron tran
sfer, i.e. from the normal to the Marcus inverted regime.