Functionalised D-π-A systems with second order nonlinear optical properties

Abstract

Molecules with high optical nonlinear response have been intensively studied in recent years and the interest has increased to develop materials which preserve this property. The orientation of the chromophores and, hence, the NLO activity, depends both on physical factors and on physico-chemical properties of materials. Functionalised organic chromophores are currently used to design multichromophores in second order nonlinear optics (NLO), in order to, for instance, enlarge the first hyperpolarizability β without the usually observed and undesired red shift of the charge transfer (CT) bands. This makes such multichromophoric systems potentially suitable as material for frequency doubling. In this work we present a convenient and versatile synthesis towards functionalized push-pull molecules bearing a hydroxyl functional group. These chromophores are of particular interest for the design of efficient nonlinear optics materials due to their potential large optical nonlinearities and their capacity to be incorporated into polymeric materials or other scaffolds. Previous results proved the efficiency of preparing multichromophores based on a calixarene scaffold. In this work we continue this study using these functionalized chromophores on suitable scaffolds to obtain a high and stable second-order NLO effect.