Density Functional Theory Study of the Secondorder Nonlinear Optical Properties of Novel Fluorenone Derivatives

Abstract

Based on the molecular structure of novel fluorenone derivative named FO52, a series of new molecules have been designed by extending its π-conjugated bridge and introducing electron donor or acceptor substituents. The electronic transition and second-order non-linear optical response properties of these fluorenone derivatives were theoretically studied in detail by using the density functional theory computational methods. The results showed that the non-linear optical response of the molecule FO52 can be improved by introducing five-membered heterocycles into its skeleton structure. In addition, the introduction of strong substituents results in significant enhancement of the first hyperpolarizability of molecular nonlinear optical properties. These fluorenone derivatives could be treated as excellent candidates for nonlinear optical materials due to the narrow energy gap of its frontier molecular orbitals, distinct intramolecular charge transfer character and large first hyperpolarizabilities.