CsVO₂F(IO₃): An Excellent SHG Material Featuring an Unprecedented 3D [VO₂F(IO₃)]⁻ Anionic Framework

The first alkali-metal vanadium iodate fluoride, CsVO₂ F(IO₃ ), with a novel 3D anionic framework, has been rationally designed and hydrothermally synthesized. The 3D [VO₂ F(IO₃ )]^- framework in CsVO₂ F(IO₃ ) is built from 0D Λ-shaped cis-[VO₃ F(IO₃ )₂ ]^4- polyanions via corner-sharing of oxo anions and bridging of the iodate groups. CsVO₂ F(IO₃ ) displays both a strong second-harmonic generation (SHG) 1.1 times as strong as KTiOPO₄ (KTP) under 2.05 μm laser radiation and high laser-induced damage threshold (LIDT) of 107.9 MW cm^-2 . This work provides a new route to design SHG crystals with stable 3D anionic structures from low-dimensional structural building units.