Isomer-specific radiative lifetimes of molecular heteroclusters

In this paper we propose a novel approach for the deconvolution of the complex spectral structure of the S₀→,S₁ electronic spectra of aromatic molecule-rare-gas heteroclusters, which rests on the experimental observation of isomer-specific radiative lifetimes of structural isomers at a fixed composition. The spectra and the pure radiative lifetimes, τ_r, of 9, 10-dichloroanthracene·Kr_n (n = 1-5) heteroclusters were measured by resonant two-photon two-color ionization. Different τ_r values for distinct spectral features of n = 3-5 heteroclusters with a fixed n allow for the distinction between structural isomers. The confrontation between experiment and a molecular theory of τ_r provides an unambiguous identification of the structural isomers of heteroclusters.