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Tunning Second-Order NLO Properties through Symmetry on Pyrazine Derivatives

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Pyrazine derivatives studied in this work

Dr. Verònica Postils Ribó is a post-doctoral researcher at the Institut des Sciences Moléculaires at the University of Bordeaux.

Catégorie : conférence/cours/séminaire (spécialisé)
Date : 11/05/2023 10:00 - 11/05/2023 11:00
Lieu : Auditorium CH22; Chemistry & Physics buildings
Orateur(s) : Dr. Verònica POSTILS RIBÓ
Organisateur(s) : Benoît Champagne
Λ and X-shaped chromophores have been proved as a good alternative to 1D chromophores to obtain large response properties adequate for electro-optic devices. In this project linear and nonlinear properties of two new series of X-shaped pyrazine-derivative chromophores with (or almost) C2v symmetry are investigated by means of density functional theory (DFT). The two series are differentiated by the orientation of the symmetry elements (C2 axis and σplane) of the point group, forming 2,3- and 2,6-isomers according to Figure 1. They comprise cyano groups as acceptor units, methoxy groups as donor units, and 2,5-thiophene groups as π-conjugated linkers that systematically enlarge the X shape of the chromophore. Focusing on the different orientation of the C2v symmetry elements and how these structural changes affect the electronic structure and the characterization of the electronic excited states of the chromophores, a rationalization of the second-order nonlinear responses (mainly Hyper-Rayleigh Scattering (HRS) hyperpolarizabilities and depolarization ratios (DR)) will be done from a fundamental point of view.  

 

Contact : Benoît Champagne - benoit.champagne@unamur.be
Télecharger : vCal