Spectroscopic properties of jet-cooled methanol clusters (n=1–6) attached to anthracene

Measurements are reported of the S0→S1 and S1→ion transition energies of jet-cooled anthracene, perturbed by contact with methanol clusters (n=1–6). Comparisons are made with similar experiments on methanol clusters nucleated by perylene and benzene. The cluster anthracene/(CH3OH)3 shows a much larger S0↔S1 red shift (527 cm−1) than n=1,2,4,5,6. This suggests a distinct conformation for the n=3 cluster, like the perylene case but unlike benzene, possibly involving a planar cyclic trimer species. Ionization threshold and photodissociation studies are used to confirm the species observed, and allow estimation of the binding energies.