(R)‐ and (S)‐SbF3(C8H9NO3): Chiral Antimony‐Based Hybrid Materials with Enhanced Second‐Harmonic Generation and Birefringence

Abstract Noncentrosymmetric (NCS) materials have garnered significant attention due to their unique second‐harmonic generation (SHG) properties, which are crucial for nonlinear optical (NLO) applications. However, achieving optimal SHG efficiency and birefringence remains challenging for Sb 3 ⁺‐based hybrid materials, which are being actively explored as potential alternatives to toxic Pb 2 ⁺‐based systems. In this study, we successfully synthesized two novel chiral NCS compounds, ( R )‐SbF₃(C₈H₉NO₃) [( R )‐Sb] and ( S )‐SbF₃(C₈H₉NO₃) [( S )‐Sb], by incorporating the stereochemically active lone pair cation Sb 3 ⁺, highly electronegative F⁻ anions, and the chiral zwitterionic 4‐hydroxyphenylglycine. The compounds crystallize in the polar noncentrosymmetric space group, P 2 1 (No. 4), featuring [SbOF₃] polyhedra that form hydrogen bonds with 4‐hydroxyphenylglycine. Notably, the Sb 3 ⁺ lone pairs align along the b ‐axis, resulting in enhanced polar characteristics. These structural features endow the compounds with outstanding NLO properties, including an SHG response 2.6 times greater than that of KH 2 PO 4 , a wide band gap of 4.19 eV, and suitable birefringence (0.184@546.1 nm). This work contributes to the expanding research on chiral hybrid materials and underscores the potential of Sb 3 ⁺‐based systems for advanced optical applications.