A series of boroselenite-based open frameworks mediated by the cationic sizes of the alkali metals

The first four metal boroselenites, namely, K2Se3B2O10, ASeB3O7 (A = Na, K), and Li2SeB8O15, have been synthesized by high temperature solid state reactions. Interestingly, the different cationic sizes and their coordination geometries led to three different types of anionic boroselenite frameworks ranging from a one-dimensional (1D) chain, to two-dimensional (2D) layers to a three-dimensional (3D) network. K2Se2B2O10 features a novel 1D [Se3B2O10]2− chain based on isolated B2O7 and SeO3 groups. ASeB3O7 (A = Na, K) feature a layered [SeB3O7]− architecture built of 1D corner-sharing B3O7 clusters that are further bridged by Se atoms. Li2SeB8O15 features an interesting 3D [SeB8O15]2− anionic framework composed of B3O7 groups and SeO3 units. Such 3D frameworks are further interpenetrated with each other into a 2-fold interpenetrating structure.