![]() Recently, various SMHBLCs were documented as different kinds of H-donors and H-acceptors that offer wide many structural shapes ( Ahmed and Khushaim, 2020 Al-Mutabagani et al., 2020c). Hydrogen bond has essential role in the formation of mesophases in liquid crystals. The hydrogen bonds are either intramolecular, when they are in the same molecule, or intermolecular, if the interacting groups belong to different molecules. In general, hydrogen bonds are non-covalent, directional interactions between H-bond donor and an acceptor such as O or N atoms. Such interactions might be H-bonding ( Paleos and Tsiourvas, 2001 Kato et al., 2006 Demus et al., 2011), or halogen bonding ( Nguyen et al., 2004 Metrangolo et al., 2006 Präsang et al., 2008 Wang et al., 2018 Alaasar et al., 2019 Saccone and Catalano, 2019) with both having the advantage of a formed liquid crystalline compound compared to covalent-bonding interactions. Supramolecular H-bonded liquid crystal complexes (SMHBLCs), which have been known for decades, began receiving more attention in the middle of the 20th Century ( Fairhurst et al., 1998). The normalized entropy of the clearing transitions (∆S/R) was calculated to illustrate the molecular interaction enhancements with the chain lengths. The relation between the dimensional parameters was established to show the effect of the aspect ratio on the mesophase range and stability. Finally, the density functional theory computational modeling has been carried out to explain the experimental findings. Also, the mesomorphic temperature ranges decreased in the order I/A6 > I/A8 > I/A10 > I/A16 with linear dependency on the chain length. All formed complexes (I/An) were studied by the use of differential scanning calorimetry and their phase properties were validated through the use of polarized optical microscopy Results of mesomorphic characterization revealed that all presented complexes exhibited enantiotropic mesophases and their type was dependent on the terminal lengths of alkoxy chains. Moreover, binary phase diagrams were established for further confirmation. FT-IR, temperature gradient NMR, Mass Spectrometer and Chromatography spectroscopy were carried out to confirm the -CN and −COOH H-bonded complexation by observing their Fermi-bands and the effects of the 1H-NMR signals as well as its elution signal from HPLC. All prepared complexes were prepared from 4-n-alkoxybenzoic acid (An) and N-4-cyanobenzylidene-4-n-(hexyloxy)benzenamine (I). 7College of Sciences, Chemistry Department, Madina Monawara, Taibah University, Al-Madina, Saudi ArabiaĪ new selection of supramolecular liquid crystal complexes based on complementary molecules formed via hydrogen-bonding interactions is reported.6King Abdullah University of Science and Technology, Analytical Chemistry Core Lab, Thuwal, Saudi Arabia.5King Abdullah University of Science and Technology, Core Labs, Thuwal, Saudi Arabia.4King Abdullah University of Science and Technology (KAUST), Biological and Environmental Sciences and Engineering Division (BESE), Thuwal, Saudi Arabia.3Department of Chemistry, Faculty of Science, Cairo University, Cairo, Egypt.2Faculty of Science, Chemistry Department, Alexandria University, Alexandria, Egypt.1College of Sciences, Chemistry Department, Yanbu, Taibah University, Yanbu, Saudi Arabia.Alnoman 1, Mariusz Jaremko 4, Abdul-Hamid Emwas 5, Salim Sioud 6 and Khulood A.
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