Magnetic circular dichroism spectroscopy and electronic structures of C₃ symmetry buckybowls

TD-DFT and ZINDO/s calculations of C_3v and C₃ symmetry buckybowls are reported. Magnetic circular dichroism (MCD) spectroscopy has been used to validate the theoretical descriptions of the electronic structures and the optical spectroscopy, with Michl's perimeter model used as a conceptual framework to analyze the results. The MCD spectroscopy has been found to be broadly similar to that reported previously for triphenylene. Two weak Gaussian-shaped Faraday ^B0 terms at lower energy can be readily assigned to forbidden L₁ and L₂ transitions; while an intense derivative-shaped Faraday ^A1 term at higher energy is assigned to the allowed B transition.