A Theoretical Investigation on Second-Order NLO Properties of Organic Substitutions of [Mo6O19]2- and [MoW5O19]2-

Abstract

In this study, density functional theory (DFT) was used to calculate second-order polarizabilities and second-order polarizabilities densities of a series of organic substitution for Lindqvist-type polyoxometalates (POMs), and the nonlinear optical (NLO) properties was also analyzed. We found that βzzz has the main contribution to β value. The expansion of molecular structure on z-axis greatly increased second-order polarizabilities. Both the size of the organic segments and metal hybridization exert an influence on β value. The analysis on the second-order polarizabilities density is used to explain the NLO phenomenon. In the present investigation, metal hybridization and π-conjugation changed the contribution of βzzz value from different parts. The results of this work will contribute to the potential applications in high-performance NLO materials.