Molecular design and theoretical study of one- and two-photon absorption properties for trinaphthylamine-centered pseudo octupolar molecules

DFT B3LYP/6-31G∗ method was used to calculate the equilibrium geometries and electron structures of a series of trinaphthylamine-centered pseudo octupolar molecules; ZINDO/SOS method was used to calculate the one-photon absorption(OPA) and two-photon absorption(TPA) properties. The calculated results show that 3(4-pyridinylvinyl)- trinaphthylamine (TN-3PY) has better OPA and TPA properties than 3(4-pyridinylvinyl)-triphenylamine (TP-3PY) because of the stronger electron-donating property of trinaphthylamine relative to triphenylamine. The TPA cross-sections of 2-benzoxazolyl (BZO) ended molecules are all larger about 1000 GM than those of 4-pyridinyl (PY) ended ones; however their transparencies are not better than those of PY-ended molecules. When N atom in trinaphthylamine is replaced by B or Al, the octupolar molecules obtained do not show better TPA properties because B and Al have electron-accepting properties.