Design synthesis experimental and theoretical dft investigation on hydrogen bond binary liquid crystal system

Abstract

Solid possesses definite melting point, directional and structural newlineproperties whereas, isotropic liquid retains identical properties in all directions. newlineHowever, Liquid Crystals (LCs) have shared both anisotropic and isotropic newlineproperties. LC is a distinct organic substance that exists between solid and liquid newlinemolecules. At the specific temperature, LC exhibits a certain molecular newlinestructure, which can be compared with the crystal state. Materials with newlineLC properties are represented as solid amorphous at a definite temperature and newlineabove the high-temperature range, it characterizes as fluid state. Thermotropic newlineLC research is a highly functional approach that makes the very effective in the newlinephotonic devices such as flat-screen displays, sensors and optical modulators etc. newlineIntermolecular interaction between the hydrogen atoms of different newlinemolecular groups is known as hydrogen bond. Aromatic acid along with newlinealkyl/alkyloxy terminal groups exhibit the mesophase by dimerization of their newlinecarboxylic acid (R-COOH) groups. Intermolecular H-bonds are crucial in the newlineassembly of molecules in LCs. Therefore, new mesogenic phases induced by newlineHydrogen Bond Liquid Crystals (HBLCs) are causing greater consciousness newlineamong LC researchers owing to their significant applications in various field. newlineCurrently, the researcher focused on the thermochromic nematogen and newlinesmectogenic mesophase, which are widely used in industrial and commercial newlineapplications.Homologous sequence of HBLCs are designed and synthesized from the newlinemixture of carboxylic acids. In this thesis the different HBLC mixture is derived newlinefrom Diglycolic acid (DGA), Thiodigycolic acid (TDGA), Aminobenzoic acid newline(ABA), and p-n-alkyloxybenzoic acid (nOBA). Further, the Methylene blue newline(MB) dye compound is doped with (DGA+12OBA) HBLC mixture and newlinep-n-dodecyloxybenzoic acid (12OBA).The different instruments are used to characterize the synthesized HBLCs mixture. HBLCs are analyzed using a highly sophisticated instrument newlinelike Fourier Transform-Infrared Spectrometer (FTIR) for H-bond confirmation newlineof DGA+5 to 12OBA, TGA+10 to 12OBA, and ABA+12OBA. Further, Nuclear newlineMagnetic Resonance Spectroscopy (NMR) for chemical structure and X-ray newlineDiffraction Spectroscopy (XRD) to identify the nature of the crystalline newlinecompounds. newline newline