Deuterium isotope effects in the spectra of jet-cooled perylene/methane aggregates

Spectral hole-burning experiments have measured the electronic spectra of aggregates of different deuterium-substituted isotopomers of methane (≤4:1) with perylene. At ≃2-cm -1 resolution, detail in the spectrum reveals at least two isomers each at the 1:1 level for the CH 4 , CH 3 D, and CH 2 D 2 complexes. Splitting observed for the CH 4 species (≃2 cm -1 ) suggests the presence of distinct nuclear spin isomers. The 1,1 aggregate contains two separate methane species, the motion of which is limited only by the perylene molecule. The detailed spectrum of this species differs radically from that of the other isomer (2,0), which contains a contacted methane dimer