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Updated: Aug 7, 2026

Novel Techniques for Observing Structural Dynamics of Photoresponsive Liquid Crystals
Published on: May 29, 2018
Effect of polarity and structural design on molecular photorefractive properties of heteroaromatic-based push-pull
Graziano Archetti1, Alessandro Abbotto, Rüdiger Wortmann
1Department of Materials Science and INSTM, University of Milano-Bicocca, Via Cozzi 53, 20125 Milano, Italy.
Abstract:
A combined experimental (optical and electro-optical absorption measurements) and computational (ab initio RHF and DFT) approach has been used to investigate the molecular low- and high-T(g) photorefractive (PR) performances of neutral and zwitterionic heteroaromatic dipolar chromophores in terms of structural and solvent-polarity effects. We have found that the nature of the building units (donor, acceptor, and spacer) and the polarity of the surrounding medium strongly affect all the relevant ground-state and nonlinear optical properties involved in the PR activity, that is, the dipole moment, the polarizability anisotropy, and first hyperpolarizability of the electronic ground-state. The variation of these properties is in turn transferred to molecular low- and high-T(g) PR figures of merit. It is shown that PR molecular performance not only relies on a proper choice of structural components but varies by orders of magnitude as a function of the medium polarity, and this suggests that a combination of molecular design and host-matrix engineering is required for optimized performances of PR materials.
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