Two Hydroxyfluorooxoborates Achieving Deep‐Ultraviolet Cutoff Edges and Moderate Birefringence by Assembling Multi‐Anionic Groups

Abstract

AbstractAssembling multi‐anionic groups is conducive to utilizing respective advantage to achieve the enhancement of optical performance. Two new hydroxyfluorooxoborates, Ama2‐Rb2B3O3F4(OH) and K8Cs2B15O14(OH)7F20 ⋅ H2O with [B3O3F4(OH)] six‐membered rings were synthesized for the first time. The title compounds exhibit short ultraviolet cutoff edges (<200 nm) and K8Cs2B15O14(OH)7F20 ⋅ H2O possesses a moderate experimental refractive index difference of 0.051@546 nm.