Excimer formation in jet-cooled van der Waals clusters of 1-cyanonaphthalene and 1-cyano-4-methylnaphthalene

Abstract

The fluorescence excitation spectra of 1-cyanonaphthalene and 1-cyano-4-methylnaphthalene in jet expansion indicate the formation of van der Waals clusters of these compounds. The excitation of the cluster bands (n > 3–4) affords a large Stokes-shifted excimer fluorescence with decay times of 140–150 ns, while that of the dimer band gives only short wavelength resonance fluorescence. Similar excimer fluorescence was detected by excitation of the ground-state dimer in a low temperature (77 K) rigid solution of 3-methylpentane and also of polycrystalline samples of these compounds.