Theoretical investigation of the second and third order nonlinear optical properties of some fused heterocyclic aromatic compounds

We report herein the results of coupled perturbed Hartree-Fock (CPHF) ab initio extended basis set calculations on the geometric structures, dipole moments, static first-order (alpha), second-order (beta), and third-order polarizabilities (gamma) of a series of fused heterocyclic aromatic compounds based on quinoline. The effects of the presence/absence of the heteroatom as well as the introduction of other substituents at various positions in the ring system on these molecular properties are described. The effect of the presence of N-oxide is also examined. Suggestions for the design of heterocyclic systems with enhanced polarizabilities are made.