The formation of heterogeneous van der Waals complexes in helium droplets

The formation of the heterogeneous van der Waals complexes of tetracene with two and three argon atoms in helium droplets have been studied using the pick up technique. The laser-induced fluorescence spectra were measured with embedding of the chromophore tetracene molecule prior to the argon atoms and vice versa. The results indicate that once the Arn complex is formed within the helium droplet it remains intact upon subsequent attachment of the tetracene molecule. This observation suggests a strategy of formation and study of larger hetero complexes where the possible number of structural isomers can be considerably reduced.