American Chemical Society
cg7b00404_si_001.pdf (1.72 MB)

Ethyne-Linked Push–Pull Chromophores: Implications of Crystal Structure and Molecular Electronics on the Quadric Nonlinear Activity

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journal contribution
posted on 2017-06-21, 00:00 authored by Paul Kautny, Helene Kriegner, Dorian Bader, Michal Dušek, Georg A. Reider, Johannes Fröhlich, Berthold Stöger
Three ethyne-linked push–pull materials consisting of a dimethylaniline donor and acceptors of increasing electron-withdrawing strength were prepared as nonlinear optical chromophores. Despite a high similarity of the molecular structures, all three materials featured unrelated non-centrosymmetric crystallization behavior. One of the compounds exhibits a remarkable packing with Z′ = 16 molecules in the asymmetric unit forming two interpenetrating subsystems. Inspection of the nonlinear optical activity of single crystalline powders revealed an extraordinarily efficient second harmonic generation of one of the materials with a 1200-fold increased second harmonic response compared to potassium dihydrogen phosphate. The second harmonic generation efficiency of the materials under investigation has been related to both the intrinsic molecular properties as well as the alignment of the individual chromophores within the crystal packing, highlighting the importance of a multidisciplinary approach to understand the properties of nonlinear optical materials.