Borate Fluoride and Fluoroborate in Alkali-Metal Borate Prepared by an Open High-Temperature Solution Method

By incorporation of the largest-electronegativity F atoms into borate, two novel halogen-containing borates, Li6RbB2O6F and K3B3O3F6, have been synthesized. Interestingly, Li6RbB2O6F is the first borate fluoride in alkali-metal borate. Meanwhile, K3B3O3F6 appears to be the first confirmed alkali-metal fluoroborate crystal grown by a high-temperature solution in air.