Electronic energies, dipole moment matrix elements, and static polarizabilities and hyperpolarizabilities for some diphenyl molecules

Abstract

The "giant dipole" molecules, NR1R2—C6H4—(C≡C)n—C6H4—NO2n = 0, 1, 2, are studied theoretically for three sets of substituents: R1 = R2 = H, R1 = H, R2 = CH3, and R1 = R2 = CH3. For each of these nine molecules, the energies, and permanent and transition dipole moments for the 20 lowest electronic states are calculated using the intermediate neglect of differential overlap (INDO) approximation at the configuration interaction with single excitations (CIS) level. Static polarizabilities and hyperpolarizabilities for the ground states are reported for these "push–pull" molecules. The changes in the physical properties of interest due to increase in conjugation length and the inductive effect of substituents on the donor group attached to the rings are discussed. The energies and permanent and transition dipole moments for the ten lowest electronic states are tabulated for use in future studies of the spectral and dynamical effects of permanent dipoie moments on laser-induced one- and multi-photon electronic transitions in realistic models for many-level giant dipole molecules.