Dk. Palit et al., PICOSECOND STUDIES ON THE ELECTRON-TRANSFER FROM PYRENE AND PERYLENE EXCITED SINGLET-STATES TO N-HEXADECYL PYRIDINIUM CHLORIDE, Chemical physics letters, 269(3-4), 1997, pp. 286-292
Picosecond laser flash photolysis studies have been carried out on two
aromatic solutes, pyrene (Py) and perylene (Pe), in methanolic and aq
ueous micellar solutions of a cationic surfactant, hexadecyl pyridiniu
m chloride (CPC) on excitation at 355 nm. In methanolic solutions, the
addition of CPC quenches the singlet state of the aromatics giving ri
se to cation radicals, Py+. and Pe(+.), respectively. The cation radic
als either decay by geminate recombination or escape in the bulk solut
ion phase in approximate to 1000 ps. In aqueous micellar solutions of
CPC, only Py+. is observed, while for Pe, initially both the singlet a
nd the cation radical are observed immediately after the 35 ps laser p
ulse. The observed decay kinetics are explained in terms of electron t
ransfer and geminate recombination processes.