| In this work, ion vibrational structures and dynamical processes in the excited electronic states of supersonic jet-cooled gas phase alkylanilines are investigated with laser photoelectron spectroscopy. These molecules are photoionized with resonant two-photon ionization techniques. The ionization potentials and a number of ion vibrational frequencies are accurately determined by using zero kinetic energy photoelectron spectroscopy. Ab initio calculations provide insights into the bonding changes that take place in aniline and propylaniline upon ionization. Excellent agreement between calculated and measured frequencies is obtained. Picosecond pump-probe light pulses are used to investigate intramolecular vibrational relaxation in the excited electronic states of alkylanilines. It is found that the rate of intramolecular vibrational relaxation depends not only on the density of state where ionization takes place but also on the conformation of molecules. Dynamic simulations are performed to interpret the time-resolved experimental data. |
