A polyanionic borate [Zn(H₂O)₆](NO₃)₂·[Zn{B₃O₃(OH)₄}₂(H₂O)₄]·2H₂O (1) have been synthesized by a molten salt method in this work. Its crystal structure consists of [B₃O₃(OH)₄]⁻ cluster and NO₃⁻ anions. Zn²⁺ cations are covalently bonded to the polyanionic clusters and water molecules leading to a [Zn(H₂O)₆] octahedron and a [Zn{B₃O₃(OH)₄}₂(H₂O)₄] cluster, which are connected by hydrogen bonds (H-Bs) to form a fictitious 3D structure, in which the NO₃⁻ anion are filled in the void. Crystal data for 1 is as following: Monoclinic, P2₁/c, a = 11.2817(12)Å, b = 6.5374(7)Å, c = 17.668(2)Å, α = 90.00°, β = 100.981(5)°, γ = 90.00°, Z = 2. Two isostructural compounds, [Co(H₂O)₆](NO₃)₂·[Co{B₃O₃(OH)₄}₂(H₂O)₄]·2H₂O (2) and [Ni(H₂O)₆](NO₃)₂·[Ni{B₃O₃(OH)₄}₂(H₂O)₄]·2H₂O (3) have been obtained by similar molten salt method, indicating the structure of 1 can be manipulated by replacement of Zn²⁺ with Co²⁺ or Ni²⁺. Structures of the borates have been further confirmed by element analysis, FTIR, PXRD, TG, and UV–vis diffusion reflectance spectra. The bandgap of the borates showed a tunable performance with a change of metallic ions. Furthermore, we studied that flame retardant property of 1 by mixing it with Acrylonitrile Butadiene Styrene (ABS). The cone calorimetry tests confirmed that ABS/1 composites with 15 wt% loading of 1 exhibited superior performance.

聚阴离子硼酸盐[Zn（H ₂ O）₆ ]（NO ₃）₂ ·[Zn {B ₃ O ₃（OH）₄ } ₂（H ₂ O）₄ ]·2H ₂ O（1）的合成熔盐法在这项工作中。其晶体结构由[B的₃ ö ₃（OH）₄ ] ^-簇和NO ₃ ^-的阴离子。Zn ²⁺阳离子与聚阴离子簇和水分子共价键合，形成[Zn（H ₂ O）₆]八面体和[锌{B ₃ ö ₃（OH）₄ } ₂（H ₂ O）₄ ]簇，其通过氢键（H-BS）连接，以形成一个虚构的三维结构中，NO，其中₃ ^-阴离子填充在空隙中。1的晶体数据如下：单斜晶，P2 ₁ / c，a  = 11.2817（12）Å，b  = 6.5374（7）Å，c  = 17.668（2）Å，α  = 90.00°，β  = 100.981（5） °，γ  = 90.00°，Z  =2。两个同结构的化合物，[Co（H ₂O）₆ ]（NO ₃）₂ ·[Co {B ₃ O ₃（OH）₄ } ₂（H ₂ O）₄ ]·2H ₂ O（2）和[Ni（H ₂ O）₆ ]（NO ₃）₂ ·[Ni {B ₃ O ₃（OH）₄ } ₂（H ₂ O）₄ ]·2H ₂ O（3）已通过类似的熔盐法获得，表明1的结构可通过取代锌²⁺与Co ²⁺或Ni ²⁺。硼酸盐的结构已通过元素分析，FTIR，PXRD，TG和UV-vis扩散反射光谱进一步证实。硼酸盐的带隙随着金属离子的变化表现出可调的性能。此外，我们通过将其与丙烯腈丁二烯苯乙烯（ABS）混合来研究其1的阻燃性。锥形量热测试证实，具有15 wt％的1的ABS / 1复合材料表现出优异的性能。