Three structural types of carbon cluster anions and the magic numbers

Abstract

Abstract The distribution of negative carbon clusters, C , is studied in the size range from 4 to 100 atoms using a Smalley compact supersonic source interfaced to a Fourier transform mass spectrometer. Tht mass spectrum of the anion clusters shows three regions which, based on earlier work, can be assigned to three different types of structures: chain, monocyclic and fullerene. The boundaries observed for the three regions in the mass spectrum suggest that the transition from chain to cyclic structure occurs between C and C , and the one from cyclic structure to fullerene occurs in the region of C to C . Magic numbers in the cyclic cluster region are found to be 17, 21, 25, 29 and 33 ( n = 4 m + l), and in the fullerene region, 60 and 74. Water can react with carbon clusters in the supersonic source to form hydrogenation products followed by electron attachment to give C n H − and C n H (for even n smaller than about 22). With argon as the target gas, only small C ( n < 14, except n = 4) are observed to undergo low energy collision‐induced dissociation (CID) yielding mainly C . While CID of C n H − gives C , no product was observed during CID of C n H .