Two Distinct Solvated
Structures of Para-Nitroaniline
in Acetonitrile and Their
Dissociation and Reassociation
Dynamics
K. Mohanalingam,1S. Yamaguchi,2and H. Hamaguchi1,3
Received12 May 1997
Abstract
We have measured the femtosecond time-resolved absorption spectra of para-nitroaniline
in acetonitrile just after the photoexcitation to the lowest excited singlet state. The
Singular Value Decomposition (SVD) analysis shows that two temporal evolutions
follow the photoexcitation. The fast component (0.7 ps time constant) describes the
dissociation of the 1:2 associated form to generate the 1:0 form followed by its
reassociation with AN molecules. A slower temporal evolution of 10 ps is most likely to
represent the cooling down process of the whole system.