Metallofullerenes as potential candidates for the explanation of astrophysical phenomena

Detection of complex organic species in space has been one of the biggest challenges of the astrophysical community since the beginning of space exploration, with C₆₀-fullerene representing one of the largest molecules so far detected. The presence of small metal-containing organic molecules, like MgNC or CaCN, in space, promoted the idea that C₆₀ may also interact with metals and form metallofullerenes based on the fact that in certain circumstellar and interstellar environments, the ingredients for the formation of metallofullerenes, i.e., metal and fullerenes, are abundant. In this perspective, we summarized the current effort to explore the presence of metallofullerenes in space, which started soon after the discovery of fullerenes about 40 years ago. Several implications of astrophysical phenomena were briefly discussed and shown to be addressable as the possible consequence of metallofullerenes' presence. We highlighted the spectral fingerprints that might be followed to achieve the future detection of cosmic metallofullerenes from a combined effort of laboratory and quantum chemical calculations. These results are expected to gain great importance with the James Webb Space Telescope (JWST), whose capability of unprecedented high sensitivity and high spectral resolution in the far- to mid-infrared range could aid the unequivocal detection of metallofullerenes in space.