Faculty of Chemistry, University of Warsaw, Pasteura 1, 02-093, Warsaw, Poland.
Dalton Trans. 2011 May 7;40(17):4407-13. doi: 10.1039/c0dt01491e. Epub 2011 Mar 15.
We describe the successful synthesis of the first mixed-cation (pseudoternary) amidoborane, Na[Li(NH(2)BH(3))(2)], with theoretical hydrogen capacity of 11.1 wt%. Na[Li(NH(2)BH(3))(2)] crystallizes triclinic (P1) with a = 5.0197(4) Å, b = 7.1203(7) Å, c = 8.9198(9) Å, α = 103.003(6)°, β = 102.200(5)°, γ = 103.575(5)°, and V = 289.98(5) Å(3) (Z = 2), as additionally confirmed by Density Functional Theory calculations. Its crystal structure is topologically different from those of its orthorhombic LiNH(2)BH(3) and NaNH(2)BH(3) constituents, with distinctly different coordination spheres of Li (3 N atoms and 1 hydride anion) and Na (6 hydride anions). Na[Li(NH(2)BH(3))(2)], which may be viewed as a product of a Lewis acid (LiNH(2)BH(3))/Lewis base (NaNH(2)BH(3)) reaction, is an important candidate for a novel lightweight hydrogen storage material. The title material decomposes at low temperature (with onset at 75 °C, 6.0% mass loss up to 110 °C, and an additional 3.0% up to 200 °C) while evolving hydrogen contaminated with ammonia.
我们成功合成了首个混合阳离子（伪四元）酰胺硼烷 Na[Li(NH(2)BH(3))(2)]，其理论储氢量为 11.1wt%。Na[Li(NH(2)BH(3))(2)] 结晶为三斜晶系（P1），空间群为 P1，a = 5.0197(4) Å，b = 7.1203(7) Å，c = 8.9198(9) Å，α = 103.003(6)°，β = 102.200(5)°，γ = 103.575(5)°，V = 289.98(5) Å(3) (Z = 2)，这一结果也被密度泛函理论计算所证实。其晶体结构在拓扑上不同于正交晶系的 LiNH(2)BH(3)和 NaNH(2)BH(3)，Li 和 Na 的配位环境也明显不同（Li 有 3 个 N 原子和 1 个氢阴离子，而 Na 有 6 个氢阴离子）。Na[Li(NH(2)BH(3))(2)] 可以看作是路易斯酸（LiNH(2)BH(3)）和路易斯碱（NaNH(2)BH(3)）反应的产物，是一种很有前途的新型轻质储氢材料。该材料在低温下（起始温度为 75°C，6.0%质量损失发生在 110°C 以下，110°C 至 200°C 之间再损失 3.0%）分解，同时释放出含有氨的氢气。
