Quantum chemical and molecular dynamics simulations of photoinduced UV-absorption and circular dichroism of a new synthesized symmetrical-base derived from condensation of two mole 5-(4-diethylamino-phenyl)-penta-2,4-dienal with a chiral diamine were performed. Photoinduced changes from trans- to cis-isomers in chromophore and transitions between the trans–trans and cis–cis isomers corresponding to right- and left-enantiomers through the metastable cis–trans conformation may explain the observed spectral measurements. The crucial role in the observed transitions is played by CC bonds close to the benzyl planes of the bis-based molecules (bis-Schiff base, BSB). At the same time rotation of the benzoate rings (about 110°) seems to be important. The performed simulations show that among the calculational technique Adamo–Barone DFT method gave better agreement with experiment.