Picosecond ultraviolet multiphoton laser photolysis and transient absorption spectroscopy of liquid benzenes

Ultraviolet multiphoton excitation with a picosecond laser pulse at the wavelength of no appreciable ground-state absorption has been used to excite benzene and alkylbenzenes homogeneously in the neat liquid state and to investigate their photophysical and photochemical primary processes by picosecond time-resolved transient absorption spectral measurements. The excimer formation processes in neat liquid benzenes excited by two-photon absorption of the 355-nm picosecond pulse from a Nd³⁺:YAG laser have been confirmed to proceed via ionization and recombination processes, and the lifetime of the ionized (ion pair) state has been determined to be 10-20 ps in neat benzene.