Are Fulleranes Responsible for the 21 Micron Feature?

摘要

cqvip:Recent detections of C60,C70,and C60^+ in space induced extensive studies of fullerene derivatives in circumstellar environments.As the promising fullerene sources,protoplanetary nebulae(PPNe)shows a number of unidenti ed bands in their infrared spectra,among which a small sample exhibits an enigmatic feature at ~21μm.Hydrogenation converts fullerenes into fulleranes,which breaks the symmetry of fullerene molecules and produces new infrared bands.In this work,we investigate the possibility of fulleranes(C60Hm)as the carrier of the 21μm feature in terms of theoretical vibrational spectra of fulleranes.The evidences favoring and disfavoring the fullerane hypothesis are presented.We made an initial guess for the hydrogen coverage of C60Hm that may contribute to the 21μm feature.