Chiral Side Groups Trigger Second Harmonic Generation Activity in 3D Octupolar Bipyrimidine-Based Organic Liquid Crystals

Stijn Van Cleuvenbergen , Przemysław Kędziora (1) , Jean-Luc Fillaut (2) , Thierry Verbiest (3) , Koen Clays (4) , Huriye Akdas-Kilig (2) , Franck Camerel (2)

1 Institute of Computing Science [Poznan]
2 ISCR - Institut des Sciences Chimiques de Rennes
3 INPAC - Department of Chemistry, University of Leuven
4 University of Leuven Department of Chemistry

The design of efficient noncentrosymmetric materials remains the ultimate goal in the field of organic second-order nonlinear optics. Unlike inorganic crystals currently used in second-order nonlinear optical applications, organic materials are an attractive alternative owing to their fast electro-optical response and processability, but their alignment into noncentrosymmetric film remains challenging. Here, symmetry breaking by judicious functionalization of 3D organic octupoles allows the emergence of multifunctional liquid crystalline chromophores which can easily be processed into large, flexible, thin, and self-oriented films with second harmonic generation responses competitive to the prototypical inorganic KH2PO4 crystals. The liquid-crystalline nature of these chiral organic films also permits the modulation of the nonlinear optical properties owing to the sensitivity of the supramolecular organization to temperature, leading to the development of tunable macroscopic materials.

Keywords: liquid crystals; nonlinear optics; chirality; thin films; bipyrimidine

Domains: Chemical Sciences

Stijn Van Cleuvenbergen, Przemysław Kędziora, Jean-Luc Fillaut, Thierry Verbiest, Koen Clays, et al.. Chiral Side Groups Trigger Second Harmonic Generation Activity in 3D Octupolar Bipyrimidine-Based Organic Liquid Crystals. Angewandte Chemie International Edition, 2017, 56 (32), pp.9546--9550. ⟨10.1002/anie.201705138⟩. ⟨hal-01578551⟩