Photoinduced Polymerization of Solid C 60 Films

Abstract
We report experimental evidence for the photopolymerization of C 70 films under irradiation with visible or UV light. The tendency of C 70 to dimerize is also confirmed by molecular dynamics calculations which find that the lowest energy dimer configuration contains a four-membered ring between monomers, similar to that calculated for the C 60 dimer or ‘bucky dumbell’. However, the cross section for this phototransformation is found to be considerably smaller than observed for C 60 , and this is attributed to a reduction in the number of reactive double bonds from 30 in C 60 to only 5 in each polar cap of a C 70 molecule.