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    Application of a Novel Symmetric Benzophenone Derivative Schiff Base in Lyotropic Media and Spectroscopic Properties
    (Pleiades Publishing Inc, 2024) Suhta, A.; Meral, S.; Agar, A. A.; Sutay, B.; Lopez, E. M. Vazquez; Coruh, U.
    The structural and spectroscopic properties of a new -ONNO- type Schiff base were analyzed. The compound 6,6 '-((1E,1 ' E)-(hexane-1,6-diylbis(azaneylylidene))bis(phenylmethaneylylidene))bis(3-(octyloxy) phenol) was synthesized by condensing a diamine and a ketone in tetrahydrofuran, resulting in a high yield. The symmetric Schiff base, in which both amine ends converted to the imine structure, was examined using XRD, NMR, IR and UV-Vis spectroscopies. The theoretical calculations were done successfully using DFT approach at 6-31G(d,p) basis set to investigate the properties of the title compound that cannot be studied by experimental analyses. NBO analysis was used to study hyper-conjugative interactions involving the overlap of sigma or pi electrons and electron density between adjacent atoms and to determine the stabilization energy. The DFT theoretical parameters and XRD experimental parameters were compared and showed good agreement. 2D fingerprint and 3D Hirshfeld surface plots were obtained to determine the intermolecular interactions. The features of the optimized structure were investigated by several analyses such: NBO, Frontier molecular orbitals, ESP, MEP and ECT which cannot be studied by theoretical methods. The UV-Vis spectroscopy was used to investigate the interaction of the synthesized benzophenone Schiff base compound with lyotropic media. The synthesized compound is significantly compatible with the prepared lyotropic medium due to its highly symmetrical and amphiphilic structure.
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    Öğe
    Synthesis, characterization and effects to cholesteric lyotropic liquid crystal media of -ONNO- type Schiff bases and metal complexes
    (Bulgarska Akademiya na Naukite, 2024) Meral, S.; Ağar, A. Alaman
    Lyotropic liquid crystals (LLC) are remarkable candidates in biomimetic applications, and in this respect, their interaction mechanisms with the target molecule are controversial. The study aims to create an ordered host system for biosimilar guest molecules to determine interactions. -ONNO- type tetradentate julolidine derivative, symmetric Schiff bases were synthesized with 1,2-ethandiamine and 1,4-butanediamine, and then copper complexes were obtained from Schiff bases with a cage-like structure. To characterize the synthesized compounds FT-IR, 13C and 1H-NMR and UV-vis spectroscopies were employed. Decylammonium chloride (DACl), NH4Cl, H2O and the optically active amphiphilic molecule L-alanine decyl esther (L-ADE) as a chiral dopant were utilized in the host system. The properties of lyotropic cholesteric phases and the effects of the synthesized compounds were examined using a polarized optical microscope (POM) by measuring the helical pitch as a parameter. Synthesized Schiff bases and metal complexes (2.5-20 mM) were added to the cholesteric phase whose helical pitch was measured at 110 µm without destroying anisotropic properties. The synthesized compounds caused a lengthening in helical pitch due to settled micelles on the surface or within the micelle core, leading to a change in micelle-micelle interaction. Specifically, Cu(ac)2·H2O shortened the helical pitch. © 2024 Bulgarian Academy of Sciences, Union of Chemists in Bulgaria.