Theoretical Investigations on the Spectroscopic and Third-Order Nonlinear Optical Properties of C106 Isolated-Pentagon Rule Fullerenes

Abstract

The lowest-lying 10 isomers of C106 satisfying the isolated-pentagon rule (IPR) were predicted from 1233 IPR isomers with semiempirical and density functional theory based methods. The structures, stabilities, IR and UV spectroscopic, and the third-order nonlinear optical (NLO) properties of those low-lying isomers were explored in detail. Cs:331, C2:1194, and C1:534 are the three lowest-energy isomers with almost identical energies and could be observed in experiment. When the entropy effects in the isomeric fullerene system are taken into account, isomer C2:1194 prevails up to 3000 °C. In the high temperature region, the concentrations of those ten low-lying isomers are very similar, indicating that the isomers at high temperatures will be hard to isolate. The third-order NLO properties under external fields (0.0–3.0 eV) of the five lowest-lying isomers were analyzed, and the average NLO properties of those isomers were predicted at room temperature for experimental exploration.