Theoretical studies on charge transport and optical properties of tris(N-saclicylideneanilines)

The structural, charge transport and optical properties of the discotic liquid crystalline molecule tris(N-saclicylideneanilines) (TSANs) have been studied using quantum chemical methods. The TSANs have enol-imine and keto-enamine tautomeric forms, and the relative energy calculations show that the keto form is more stable than the enol form. The effective charge transfer integral and site energy corresponding to the hole and electron transport in TSAN molecules were calculated directly from the matrix elements of Kohn-Sham Hamiltonian. The calculated charge carrier mobility using the Monte Carlo simulation of the polaron hopping transport method shows that the TSAN molecules are n-type organic semiconductors and the charge transport strongly depends on the substituted functional groups and the orientation of the pi-stacked molecules. The absorption and emission spectra of TSANs have been analyzed using a time-dependent density functional theory (TDDFT) method. The results obtained from this study will reveal the relationships between the molecular structure and charge transport as well as the optical properties of the TSAN molecules.