Three polyborates, namely, LiNa11B28O48, Li1.45Na7.55B21O36, and Li2Na4Ca7Sr2B13O27F9, were synthesized via the
high-temperature
solution method. All of them feature high-symmetry [B12O24] units, yet their anion groups exhibit distinct dimensions.
LiNa11B28O48features a three-dimensional
anionic structure of3[B28O48]∞framework, which is composed of three units: [B12O24], [B15O30], and [BO3]. Li1.45Na7.55B21O36possesses a one-dimensional anionic structure of1[B21O36]∞chain consisting of [B12O24] and [B9O18] units.
The anionic structure of Li2Na4Ca7Sr2B13O27F9is composed
of two zero-dimensional isolated units, namely, [B12O24] and [BO3]. The novel FBBs [B15O30] and [B21O39] are present in LiNa11B28O48and Li1.45Na7.55B21O36, respectively. The anionic
groups in these compounds exhibit a high degree of polymerization,
thereby augmenting the structural diversity of borates. And the crystal
structure, synthesis, thermal stability, and optical properties were
meticulously discussed to guide the synthesis and characterization
of novel polyborates.