The solvatochromism, electronic structure, electric dipole moments and DFT calculations of benzoic acid liquid crystals

Abstract

ABSTRACT The electronic transitions of 4-(decyloxy) benzoic acid (4DOBA), 4-undecyloxybenzoic acid (4UDOBA) and 4-(dodecyloxy) benzoic acid (4DDOBA) liquid crystals (LCs) have been investigated by using optical absorption and steady-state fluorescence spectra of in a series of different polarity organic solvents. Two electronic transition bands have been observed in steady-state fluorescence spectra. The solvatochromic properties, electronic transitions and electronic structure of LC compounds have been interpreted to relation with molecular structure. Solvatochromism determining as quantitative to solvent-solute interactions (linear solvent energy relationships) have done by using Kamlet-Taft and Catalan solvatochromism. The electrical dipole moments and electronic absorbance of the LCs molecules states were calculated by using B3LYP/6-311++G(d,p) method and basis set. The ground state experimental electrical dipole moments were determined by Bilot-Kawski method, when the excited state electric dipole moments were determined by Lippert-Mataga, Bakshiev, Kawski-Chamma-Viallet and Reichardt method, respectively. HOMO (Highest Occupied Molecular Orbital), LUMO (Lowest Unoccupied Molecular Orbital), MEP (Molecular Electrostatic Potential) and SAS (Solvent Accessibility Surface) shapes of molecules in both monomer and dimer structure have been drawn and they are proved to be dimers.