C60-based composites in view of topochemical reactions

Abstract

The current paper is aimed at the determination of barriers that govern the covalent coupling between partners of C₆₀-based composites consisting of two fullerenes C₆₀ (C₆₀ dimer), C₆₀ and single-walled carbon nanotubes ([C₆₀-(4,4)] carbon nanobuds), and C₆₀ and graphene ([C₆₀-(5,5)] and [C₆₀-(9,8)] graphene nanobuds). Barrier energies are determined as coupling ones E^tot_cpl and are expanded over two contributions that present the total energy of deformation of the composites' components E^tot_def and the energy of covalent coupling E^tot_cov. In view of these energetic parameters and in contrast to expectations, seemingly identical reactions that are responsible for the formation of intermolecular [2 + 2] cycloadditions in the studied composites result in different final products. This peculiarity is suggested to occur as a result of the topochemical character of the covalent coupling between the two members of the studied composites, once additionally complicated by the varied donor–acceptor contribution.