Structural Design of Two Fluorine-Beryllium Borates BaMBe(BO)F (M = Mg, Ca) Containing Flexible Two-Dimensional [BeBOF] Single Layers without Structural Instability Problems.

Molecular structural design is a compelling strategy to develop new compounds and optimize the crystal structure by atomic-scale manipulation. Herein, two fluorine-beryllium borates, BaMgBe(BO)F and BaCaBe(BO)F, have been rationally designed to overcome the structural instability problems of SrBeBO (SBBO). When relatively large Ba atoms were introduced, the [BeBO] double layers of SBBO were successfully broken, generating flexible [BeBOF] single layers. Also, the strategy adopted in this work has many implications in understanding the structural chemistry and designing novel optical functional materials in a beryllium borate system.