Structures and stability of the hydrides of C32, C34 and C36

A systematic study was performed on C32H32, C34H34 and C36H36 at the Hartree–Fock and density functional theory levels of theory. The calculated results demonstrate that the lowest-energy isomer is classic for C32H32 and non-classic for C34H34 and C36H36. For C32H32 and C34H34, the pentagon–pentagon fusions are an important factor in determining their stability. For C36H36 the lowest-energy isomers containing heptagons are all more stable than the corresponding one of classic structures and the pentagon–pentagon fusions determine their stability. Our calculations reveal that fullerene derivatives may not only violate the isolated pentagon rule but also may be non-classic structures containing heptagon(s).