Electronic spectroscopy of jet-cooled anthracene/(H2O)n clusters (n=1–16): comparisons of inhomogeneous structure

Abstract

Measurements of the S0→S1 electronic excitation spectra of anthracene/(H2O)n clusters (n=1–16) are reported. Preliminary data on perylene/(H2O)n, n=1–8, are included for comparison with the anthracene work and with literature data involving benzene. Near-threshold ionization and ion photodissociation measurements were employed to ensure correct identification of the species being studied. However, such measurements also reveal significant differences in the dissociation energies of the ionized clusters. Several cases are reported for anthracene/(H2O)n, including n=4, 5, 10, 14, and 15, where the spectra are much simpler than for other clusters of similar size. These results are discussed in connection with literature calculations for pure water clusters, which have suggested that water tetramers, and possibly pentamers, can act as building blocks for larger clusters.