Aromaticity and electronic structural properties of selenopehene and disselenophenes

Abstract

The aromaticity and some electronic structural characteristics of selenophene and diselenophenes were theoretically investigated using density functional theory (DFT). The highest occupied molecular orbital (E_HOMO), lowest unoccupied molecular orbital (E_LUMO), difference in HOMO and LUMO energies (E_H−L), dipole moments (µ_D), relative energies differences (∆E), chemical potential (µ), chemical hardness (η), electrophilicity (ω), as well as the bond lengths differences in the ring (∆BL), Shannon aromaticity index (SA), Nucleus Independent Chemical Shift (NICS), along with the π-stacking ability using the Localized Orbital Locator Integrated Pi Over Plane (LOLIPOP) were calculated and assessed for each structure. The aromaticity indices were found in a very good agreement with each other. According to the ∆BL, SA, and NICS aromaticity indices, the 1 > 3 L > 4 > 2 > 3R, 3L > 1 > 4R > 4L ≈ 2 L > 2R > 3R and 1 > 3 L >4R > 4 L > 2 L > 2R > 3R trends were obtained, respectively showing 1 and 3 L as the most aromatic and 3R as the least aromatic rings in this study.