  The main goal of this thesis is to unveil some questions related to the
formation of complex fullerene-based molecules in space, with the aim of
resolving some key problems in astrophysics. The unexpected detections of
fullerenes and graphene (possible C24) in the H-rich circumstellar environments
of evolved stars indicate that these complex molecules are not so rare and
bring the idea that other forms of carbon such as hydrogenated fullerenes
(fulleranes), buckyonions, and carbon nanotubes may be widespread in the
Universe, being closely involved in many aspects of circumstellar/interstellar
chemistry and physics. We explore this new and fertile field of research by
focusing our study on some Galactic planetary nebulae (PNe) that contain
fullerenes. In order to do this, we make use of laboratory spectra of several
fullerene-related compounds and compare them with astronomical data. This work
is a first step to open up a new field of interdisciplinary research, crossing
the boundaries between astronomers, chemists, and physicists, and understand
the significant presence of fullerene structures in circumstellar/interstellar
environments.
