  Recent Spitzer Space Telescope observations of several astrophysical
environments such as Planetary Nebulae, Reflection Nebulae, and R Coronae
Borealis stars show the simultaneous presence of mid-infrared features
attributed to neutral fullerene molecules (i.e., C60) and polycyclic aromatic
hydrocarbons (PAHs). If C60 fullerenes and PAHs coexist in fullerene-rich space
environments, then C60 may easily form adducts with a number of different PAH
molecules; at least with catacondensed PAHs. Here we present the laboratory
infrared spectra (~2-25 um) of C60 fullerene and anthracene Dies-Alder mono-
and bis-adducts as produced by sonochemical synthesis. We find that
C60/anthracene Diels-Alder adducts display spectral features strikingly similar
to those from C60 (and C70) fullerenes and other unidentified infrared emission
features. Thus, fullerene-adducts - if formed under astrophysical conditions
and stable/abundant enough - may contribute to the infrared emission features
observed in fullerene-containing circumstellar/interstellar environments.
