Electronic Structure, Aromaticity and Optical Properties of Dehydro[10]annulene

Dehydro[10]annulene had been prepared experimentally recently, which is considered to be a highly rigid structure with planar configuration. In this paper, the electronic structure and bonding character of dehydro[10]annulene had been studied by means of molecular orbital (MO), density of states (DOS), bond order (BO) and interaction region indicator (IRI) analyses. The delocalization characters of out-of-plane and in-plane pi-electrons (pi(out)- and pi(in)-electrons) of the bond regions were studied by using localized orbital locator (LOL). The anisotropy of the induced current density (AICD), iso-chemical shielding surface (ICSS) and anisotropy of the gauge-including magnetically induced current (GIMIC) were used to investigate the molecular response to external magnetic field, including the induced ring current and the magnetic shielding characteristic. The results showed that the electron delocalization of dehydro[10]annulene is mainly contributed by pi(out) system. The apparent clockwise current in the pi(out) system proved that dehydro[10]annulene is pi(out) aromatic. Finally, the photophysical properties and (hyper)polarizability of dehydro[10]annulene were studied by TD-DFT calculation. The results showed that dehydro[10]annulene has strong local excitation characters. Its (hyper)polarizability decreases with the increase of frequency and has the characteristics of nonlinear anisotropy.

Automated summary

In this paper, the electronic structure and bonding character of dehydro[10]annulene were studied using various analysis methods. The delocalization characteristics of pi(out) and pi(in)-electrons were investigated, as well as the molecular response to external magnetic field. The results showed that the electron delocalization of dehydro[10]annulene is mainly contributed by the pi(out) system, and it exhibits pi(out) aromaticity. The photophysical properties and (hyper)polarizability of dehydro[10]annulene were also studied. The results revealed its strong local excitation characters and nonlinear anisotropy.