Nonlinear optical responses of self-Assembled monolayers functionalized with indolino-oxazolidine photoswitches

Claire Tonnelé, Kornelia Pielak, Jean Deviers, Luca Muccioli, Benoît Champagne, Frédéric Castet

Research output: Contribution to journalArticle

Abstract

A computational approach combining molecular dynamic simulations and density functional theory (DFT) calculations is implemented to evaluate the second-order nonlinear optical (NLO) responses of photoresponsive self-Assembled monolayers (SAMs) based on indolino-oxazolidine molecular switches. These numerical simulations provide a complete atomistic picture of the morphology of the SAMs, revealing a high degree of positional disorder and an almost isotropic orientation of the chromophores. Subsequent DFT calculations, carried out to evaluate the average first hyperpolarizability of indolino-oxazolidine switches within the SAM, predict that the structural disorder does not significantly reduce the NLO contrast compared to that of the isolated molecules. Chromophores in the SAM can assume a limited number of specific conformations, due to the high rotational barrier that characterize the conjugated bonds along the indolino/oxazolidine-dyene-Thiophene sequence. A notable exception is the rotation about the thiophene-Thioalkyl bond, which is not only almost free, but also strongly correlated with the magnitude of the first hyperpolarizability. Controlling this rotation by chemical design could thus be a viable strategy to optimize the SAMs NLO response and the performance of photoresponsive devices based on indolino/oxazolidine switches.

Original languageEnglish
Pages (from-to)21590-21597
Number of pages8
JournalPhysical Chemistry Chemical Physics
Volume20
Issue number33
DOIs
Publication statusPublished - 1 Jan 2018

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