Effect of molecular interactions and end chain length on ultraviolet absorption behavior and photo stability of alkoxycinnamic acids: Theoretical models of liquid crystal

Abstract

The ultraviolet (UV) absorption spectra of the liquid crystalline dimer complexes of 4-n-alkoxycinnamic acids (nOCNA: n=4, 6, 8, where n is the number of carbon atoms in the alkoxy chain) have been presented. The nOCNA structures have been optimized using the density functional Becke3–Lee–Yang–Parr (B3LYP) hybrid functional with 6-31+G (d) basis set using the crystallographic geometry as input. The electronic structures of the dimer molecules have been evaluated using the optimized geometries. The spectra of the dimer molecules have been calculated by employing the density functional theory (DFT), semiempirical complete neglect of differential overlap/spectroscopy (CNDO/S), and intermediate neglect of differential overlap/spectroscopy (INDO/S) parameterizations. The features of electronic transitions and excited states have been calculated via configuration interaction singles (CIS) with the semiempirical Hamiltonian Zerner intermediate neglect of differential overlap (ZINDO). The effect of molecular interactions and the end chain length may be reasonably useful for the progress and efforts in developing the photo-addressed color displays.