Theoretical study of electronic and nonlinear optical properties of Janus all-cis-1,2,3,4,5,6-hexafluorocyclohexane derivative with an extended π conjugation

Abstract

More and more scientists are paying attention to Janus all-cis-1,2,3,4,5,6-hexafluorocyclohexane (hereafter system 1) due to interesting structure and unique property. The question of how to design high-performance nonlinear optical (NLO) materials based on system 1 is studied. In this work, by means of ab initio calculations, a new series of system 1 derivatives with an extended π conjugation have been theoretically designed by introducing –(CH=CH)n–NO2 or –(CH=CH)n–NH2 (n = 1–4, 8, 12) chain into system 1. The results indicate that introducing –(CH=CH)n–NO2 or –(CH=CH)n–NH2 chain leads to small transition energy, which can bring a significant enhancement of the first hyperpolarizability. It is expected that these novel systems exhibit the large first hyperpolarizabilities up to 4.17 × 104 au. Moreover, the effect of different substitutions on the NLO responses is investigated. With increasing the first hyperpolarizability, the –(CH=CH)n–NH2 chain has an advantage over the –(CH=CH)n–NO2 chain. It is hoped that this work can provide theoretical help for the design of new nonlinear optical materials.