Azomethines with nonlinear optical properties and polyesters covalently functionalized with them. Syntheses with nitriles IC

Abstract

Polyesters with covalently bound azomethine and carbonanalogous dye moieties were obtained by polymer analogous reactions. Their nonlinear optical properties were examined by electric field induced second harmonic generation measurements and compared with corresponding monomeric dyes. All of them had maximum absorption wavelengths between 400 and 546 nm. Values for μβ (dipole mement μ, molecular hyperpolarizability β) reached 290×10 −68 Cm 5/V. Quantum chemical calculations indicate the existence of various conformers of the dyes with large differences in their nonlinear optical properties. Furthermore, the calculations also point to a profound sensitivity of the molecular hyperpolarizability to environmental (solvent) effects amounting to an order of magnitude.