Two-way molecular switches with large nonlinear optical contrast.

Molecular switches: Highly efficient acido- and photoswitchable frequency doublers (see scheme) based on the indolinooxazolidine core are studied by means of hyper-Rayleigh experiments and quantum-chemical calculations.To optimize the nonlinear optical (NLO) contrast, a series of indolinooxazolidine derivatives with electron-withdrawing substituents in the para position on the indolinic residue have been synthesized. Their linear and nonlinear optical properties have been characterized by UV-visible absorption and hyper-Rayleigh scattering measurements, as well as by ab initio calculations.

Acido-triggered nonlinear optical switches: benzazolo-oxazolidines.

This work is the continuation of our previous experimental and theoretical studies aiming at designing efficient nonlinear optical (NLO) switches derived from the benzazolo-oxazolidine core. Here, we report the synthesis and the characterization of the linear and nonlinear optical properties of benzothiazolo[2,3-b]oxazolidine acidochromes by means of hyper-Rayleigh scattering as well as quantum chemical calculations. It is shown that these new derivatives incorporating a benzothiazole subunit exhibit very high static first hyperpolarizability values in their acido-generated form.

Acidoswitchable NLO-phores: benzimidazolo[2,3-b]oxazolidines.

This paper presents a series of acidoswitchable NLO-phores combining the 9-methylbenzimidazolo[2,3-b]oxazolidine core with various pi systems such as phenylethenyl, phenylethynyl, and naphthylethenyl. All the prepared derivatives are shown to display acidochromic behavior at ambient temperature. The remarkable contrast in the NLO response along the reversible transformations observed in HRS experiments is rationalized by high level theoretical calculations.