Ba (BO )(CO )F: The First Borate Carbonate Fluoride Synthesized by the High-Temperature Solution Method.

In contrast to the well-investigated halogen-containing borates and carbonates, very few halogen-containing borate carbonate compounds have been reported. Specifically, no example of borate carbonate fluoride has been synthesized successfully until now. Herein, the planar π-conjugated units [BO ] and [CO ] and the F ions are introduced simultaneously into one crystal structure resulting in the first borate carbonate fluoride, Ba (BO )(CO )F, by the high-temperature solution method in the atmosphere. Its structure features a hexagonal channel formed by the [BO ] and [CO ] units with the [F Ba ] trimers filled in the channel. Various characterizations including single crystal- and powder-XRD, EDX, IR, UV-vis-NIR, and TG-DSC, together with the first principles calculation have been carried out to verify the structure and fully understand the structure-property relationships.