SbHPO3F: 2D van der Waals Layered Phosphite Exhibiting Large Birefringence

A novel antimony(III)-based phosphite, SbHPO3F, featuring a unique two-dimensional (2D) van der Waals layered structure, has been successfully designed and synthesized via the simultaneous employment of optically active moieties including SbO3F seesaw and tetrahedral HPO3 groups. Its optimized layered arrangement formed by the alternating connection of 4-membered rings (4-MRs) and 8-MRs endows the title compound with desirable optical properties including a large birefringence and short ultraviolet (UV) cutoff edge, implying that it is a potential UV birefringent material.