Five new rubidium borates, namely Na_1/3Rb_5/3[B₄O₅(OH)₄] (1), Rb₄[B₁₂O₁₈(OH)₄] (2), Rb₂Ba[B₁₂O₁₈(OH)₄] (3), Rb₂[B₅O₈(OH)] (4) and NaRb_0.5[B₆O₁₀]·0.5H₃O (5) have been synthesized under solvothermal conditions. Compound 1 features a 0D structure composed of [B₄O₅(OH)₄]²⁻ clusters. After changing the metal salt, new cyclic [B₁₂O₂₀(OH)₄]⁸⁻ clusters in 2 and 3 are formed, resulting in 1D chains. Such a chain structure is first discovered in dodecaborates. By tuning the reaction temperature and pH of the reaction media, compound 4 with a 4-connected 2D oxoboron layer constructed from partially protonated [B₅O₁₀(OH)]⁶⁻ and compound 5 with a 6-connected 3D framework constructed from [B₆O₁₃]⁸⁻ clusters are successfully isolated. Since compounds 1 and 4 crystallize in the non-centrosymmetric (NCS) space group, second harmonic generation (SHG) measurements and dipole moment calculations have been carried out. The SHG response of 4 is 2.0 times that of KH₂PO₄ (KDP), which is higher than those of related analogues.

中文翻译：

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五种具有 0D 簇、1D 链、2D 层和 3D 框架的新型硼酸铷

五种新的硼酸铷，分别是Na _1/3 Rb _5/3 [B ₄ O ₅ (OH) ₄ ] ( 1 )、Rb ₄ [B ₁₂ O ₁₈ (OH) ₄ ] ( 2 )、Rb ₂ Ba[B ₁₂ O ₁₈ (OH) ₄ ] ( 3 )、Rb ₂ [B ₅ O ₈ (OH)] ( 4 ) 和 NaRb _0.5 [B ₆ O ₁₀ ]·0.5H ₃ O ( 5) 是在溶剂热条件下合成的。化合物1具有由[B ₄ O ₅ (OH) ₄ ] ^2-簇组成的0D结构。改变金属盐后，在2和3中形成新的环状[B ₁₂ O ₂₀ (OH) ₄ ] ^8-簇，产生一维链。这种链结构首先在十二硼酸盐中发现。通过调节反应介质的反应温度和 pH 值，具有由部分质子化 [B ₅ O ₁₀ (OH)] ⁶⁻构成的 4 连接 2D 氧硼层的化合物4成功分离出具有由[B ₆ O ₁₃ ] ⁸⁻簇构建的6-连接3D框架的化合物5。由于化合物1和4在非中心对称 (NCS) 空间群中结晶，因此进行了二次谐波生成 (SHG) 测量和偶极矩计算。4的SHG响应是KH ₂ PO ₄ (KDP)的2.0倍，高于相关类似物的响应。