Abstract
The frontier molecular orbitals (FMOs) play a vital role in the process of charge transport and optical properties. We explained the distribution of highest occupied molecular orbitals (HOMOs) and lowest unoccupied molecular orbitals (LUMOs) on different individual ligands in the meridianal isomer of methyl derivatives of tris(8-hydroxyquinolino)aluminum (mer-Alq3). The structures have been optimized at the B3LYP/6-31G* level. Energy decomposition analysis has been performed at the B3LYP/DZP level. It has been explained that HOMOs are on A-ligands due to weaker electrostatic interaction energy between L-a-AlLbLc fragments while LUMOs are on B-ligands due to weaker orbital interaction energy between L-b-AlLaLc fragments. (c) 2009 Elsevier B.V. All rights reserved.