CaNa2Nb2O6OHF

CaNa2Nb2O6OHF is a mixed-anion niobate solid with the formula CaNa2Nb2O6OHF. The composition includes two niobium centers per formula unit connected by oxide ligands to form NbO6 octahedra. Calcium and sodium cations occupy interstitial sites within the framework, while hydroxide and fluoride groups balance charge and can influence the spacing between structural layers. Niobium is in the +5 oxidation state in this compound.

Structure and synthesis: The material is typically reported as a crystalline solid derived from niobate chemistry, with a framework of corner-sharing NbO6 octahedra. Mixed anions (OH− and F−) can reside in interlayer or tunnel-like positions, depending on preparation conditions. Common synthesis routes include solid-state reactions of Nb2O5 with calcium and sodium salts in the presence of a fluoride source, or hydrothermal methods, followed by heat treatment to achieve crystallinity.

Properties and applications: CaNa2Nb2O6OHF is generally insoluble in water and displays stability at elevated temperatures. The mixed-anion composition can influence dielectric properties and optical behavior, making such niobates of interest for dielectric ceramics and potentially for nonlinear optical or photocatalytic applications. As a relatively niche niobate, it is mainly studied in the context of solid-state chemistry and materials science to understand how hydroxide and fluoride incorporation affects structure and properties.

See also: CaNb2O6, NaNbO3, niobates.