PHOTOINDUCED POLYMERIZATION OF SOLID C-70 FILMS

We report experimental evidence for the photopolymerization of C70 fil ms under irradiation with visible or UV light. The tendency of C70 to dimerize is also confirmed by molecular dynamics calculations which fi nd that the lowest energy dimer configuration contains a four-membered ring between monomers, similar to that calculated for the C60 dimer o r 'bucky dumbell'. However, the cross section for this phototransforma tion is found to be considerably smaller than observed for C60, and th is is attributed to a reduction in the number of reactive double bonds from 30 in C60 to only 5 in each polar cap of a C70 molecule.