Noncentrosymmetric Fluorooxoborates A10B13O15F19 (A = K and Rb) with Unexpected [B10O12F13]7– Units and Deep-Ultraviolet Cutoff Edges

The fluorooxoborates A10B13O15F19 (A = K and Rb) were obtained successfully in the open system. They are the first examples containing two isolated fluorooxoborate units, [B10O12F13]7– and [B3O3F6]3–. To the best of our knowledge, the [B10O12F13]7– unit is a new one in the reported fluorooxoborates. The title compounds exhibit short UV absorption edges (<190 nm). Furthermore, the relationship between the structures and optical properties was uncovered by theoretical calculations. More importantly, this work enriches the species for fluorooxoborate crystal chemistry.