TRANSITION-STATE ENERGIES FROM EXPERIMENTAL SPECTRA

We present a simple method for extracting transition-state parameters for photodissociation and inversion reactions from very easily obtained experimental data. Our method uses electronic spectra to fairly accurately determine the potential energy at the minimum barrier to symmetric isomerization. Our method is inherently more sensitive to the barrier height than other methods that utilize a need to accurately measure splitting energies of the vibrational levels. The method we present derives the barrier height via the energy of a wave function sitting atop the barrier whose height is to be determined. Thus, it is suitable for dissociative, i.e., reactive potentials, as well. We present the NH3 tunneling barrier and the photodissociation of H2O as examples.