Ab initio study on fullerene C-44 and its hydrogenates

The geometrical structures and electronic properties of fullerene C-44 and its hydrogenates have been studied by using an ab initio method. The calculated results show that C-44 has four isomer conformations and their symmetries belong to D-3h or D-3d Isomer 1(D-3h(a) is the most stable. Adding hydrogen to C-44 isomers gives various exo-hydrogenates with the stability order for the carbon site in the cage as follows: 5(5)5 > 5(5)6 similar to 6(5)6 > 6(6)6. This paper also discusses the aspects that influence stability: geometrical and electronic factors. (C) 1997 by John Wiley & Sons, Ltd