Solvation dynamics of large van der Waals aniline-Arn clusters:: Experiment and theory

An experimental and theoretical study of large van der Waals aniline-Ar-n clusters (n = 7-35) has been carried out. The van der Waals shift of the S-1 <-- S-0 electronic transition and of the vertical ionization potential have been recorded by mass-resolved resonant two-photon two-color ionization techniques. Minimum energy configurations and isomerization processes have been investigated by molecular dynamics simulations. In particular, a careful analysis of the solvation structures at temperatures close to the experimental conditions has been performed by using appropriate global geometrical parameters. This approach allows a deep understanding of the evolution with size arising from the spectroscopic data. A new interpretation of the magic character of the aniline-Ar-22 cluster observed in the resonant two-photon ionization mass spectrum is proposed.