Synthetic and structural considerations on highly curved bowl-shaped fragments of fullerenes

Abstract

Abstract Numerous highly curved fragments of C 60 and unique subunits of C 70 were synthesized under mild conditions using metal-catalyzed protocols. According to X-ray crystallographic analyses, highly curved fragments of C 60 have a maximum π-orbital axis vector (POAV) pyramidalization angle of up to 12.9 °, whereas distinctive fragments of C 70 , analogous to the tube portion of the rugby-shaped buckyball, are less curved. Among the eight buckybowls studied herein, five form polar crystals. Depending on the molecular geometry, the inversion dynamics of buckybowls involves either a planar or an S-shaped (non-planar) transition structure.