Van der Waals clusters containing an aromatic compound and solvent molecules
permit us to investigate “weak” intermolecular interactions which play a key role in a
great variety of physical, chemical, and biological processes. Most of all, hydrated
clusters have attracted extensive research interest as hydrogen bonding is certainly one
of the most fundamental interactions in the solvation processes.
Recently, infrared (IR) spectroscopic studies of such clusters in gas phase combined
with ab initio calculations proved to be highly powerful to provide important
information for a clear understanding of geometric structures, intermolecular
interactions, conformational dynamics, and proton transfer processes in solvated
molecular systems. In this regard, we have explored the branching ratio and mode
selectivity in IR photodissociation of hydrogen-bonded ternary cluster ions by adopting
tandem mass spectrometry with an ultimate goal of unimolecular reaction control. Here,
we present experimental results on IR photodissociation dynamics of hydrated aniline
cluster ions by exciting different vibrational modes such as free NH of aniline+,
symmetric and anti-symmetric bonded NH of aniline+, free OH of water, symmetric and
anti-symmetric bonded OH of water.