Excited States Symmetry Breaking and In-Plane Polarization Cause Chiral Reversal in Diastereomers

• Published in: Molecules (Basel, Switzerland) Vol. 26; no. 15; p. 4680
• Main Authors: Wang, Chenglong, Wang, Jingang, Wang, Chunyang
• Format: Journal Article
• Language: English
• Published: Basel MDPI AG 02-08-2021; MDPI
• Subjects: Broken symmetry; Catalysis; Chirality; chirality reversal; Diastereoisomers; electromagnetic interaction; Electromagnetic interactions; electronic transitions; Graphene; Isomers; Light; Linear polarization; Optical properties; Organic chemistry; Pesticides; Polarization; Polycyclic aromatic hydrocarbons; Symmetry; Beijing China; United States > US; China
• ISSN: 1420-3049; 1420-3049
• DOI: 10.3390/molecules26154680

In this work, we investigate the electronic transitions and chirality of three isomers of huge conjugated systems: asymmetric diastereomers (MMMM) and two symmetrical diastereomers (PMPM and PPMM). The physical mechanism of flipping has been studied theoretically. The new ribbon-shaped polycyclic aromatic hydrocarbons (PAHs) molecule is formed by connecting three graphene-like systems with large conjugated π orbitals. By calculating and analyzing electromagnetic interaction decomposition over distance, it can be found that the chirality reversal of different energies is caused by the symmetrical fracture of TMDM in the Z direction. The chirality reversal at the same energy is caused by the in-plane polarization of the TMDM along the Y direction.