Raman spectroscopy and theoretic study of hyperpolarizability effect in diiodobutenyl‐bis‐thioquinolinium triiodide at low temperature

Abstract

Various structural features, such as proton disorder or noncovalent interactions, determine the existence of switchable nonlinear optical properties under varying external conditions. Thus, for the single crystal of diiodobutenyl‐bis‐thioquinolinium triiodide with the bridge hydrogen atom, previously characterized under ambient conditions by C2/c symmetry, we have measured Raman spectra in the temperature range from 298 K down to 113 K. Variations in low‐wavenumber region of Raman spectra at temperatures below 153 K have been attributed to the change of the bridge hydrogen atom position in the [NHN]+ fragment, thus lowering the crystal symmetry from C2/c to Cc. Quantum chemical calculations in the solid state for noncentrosymmetric Cc structure predict high hyperpolarizability and second‐order electric susceptibilities, comparable to those of modern nonlinear optical materials. This indicates the emergence of nonlinear optical properties in the low‐temperature phase of the studied crystal. Copyright © 2017 John Wiley & Sons, Ltd.

Nonlinear nanophotonic devices in the ultraviolet to visible wavelength range

“…Hydrogen bond pattern prediction based on similar quantum mechanical modeling has also been successful in the design and prediction of NLO organic molecules. Freely available shareware has popularized these methods among chemists and material scientists impacting material design in a range of fields [186][187][188][189][190][191][192][193][194]. More recent computational methods have relied on utilizing an algorithm which can quickly find minimums in the potential energy landscapes of novel organic materials.…”

Crystal structure of bis(1,3-phenylenedimethanaminium) bis(triiodide) tetraiodide – water (1/2) , C8H16I5N2O

“…The aminium group N1 forms weak hydrogen bonds with iodine atoms only, whereas the aminium group N2 forms normal to weak hydrogen bonds with two water molecules and one iodine (see the left part of the figure). [16,27,32,33] the asymmetry is dependent on the intermolecular interactions in the solid state, which are mainly hydrogen bonds in this case. The formal I4 2− anion is characterised by a I5-I6 single bond 2.7762(13) Å for the I 2 molecule [34] and two different medium strong halogen bonds [I4-I5 = 3.2538(10) Å, I6-I4′ = 3.3816(10) Å, ′ = 1−x, −1 + y, 1.5 − z].…”

Halogen and hydrogen bonding in the layered crystal structure of 2-iodoanilinium triiodide, C6H7I4N

“…Within the Raman spectrum of the title compound the lines which are characteristic for an asymmetric triiodide anion [21,33] are found at 109 cm −1 (vs) and 155 cm −1 (vs). A general overview on the spectroscopy of triiodide species is given by Deplano et al in 1999 [34], but the topic is still a matter of intense research activity [35][36][37]. Salts which are based on iodoanilines and structurally related compounds are an interesting system to study halogen bonds in competition with other forces that influence the packing schemes of the corresponding crystal structures [26,38,39].…”