Rb3SbF3(NO3)3: an excellent antimony nitrate nonlinear optical material with a strong second harmonic generation response fabricated by a rational multi-component design

Abstract

A novel antimony fluoride nitrate, Rb₃SbF₃(NO₃)₃, fabricated by a rational multi-component design, has been successfully synthesized by a rapid evaporation concentration method. This title compound crystallizes in a polar noncentrosymmetric (NCS) space group (P2₁) and presents a complicated three-dimensional (3D) network composed of SbO₃F₃, Rb-centered distorted polyhedra and π-conjugated planar triangular NO₃ groups. Rb₃SbF₃(NO₃)₃ is a potential UV nonlinear optical material due to its large phase-matchable second harmonic generation (SHG) response of approximately 2.2 times that of KH₂PO₄ (KDP) and a wide band gap of 3.75 eV. Theoretical calculation analysis was used to rationalize the large SHG effect, which originates from the multi-component synergistic effect including moderately polarizable Rb⁺ cations, a stereochemically active lone pair effect of Sb³⁺ and NO₃ groups with a π-conjugated planar triangular structure.