On the composition and crystal structure of the new quaternary hydride phase Li4BN3H10.
On the composition and crystal structure of the new quaternary hydride phase Li4BN3H10.
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DOI：
10.1021/ic0518226
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发表时间：
2006-01
影响因子：
4.6
通讯作者：
Y. Filinchuk;K. Yvon;G. Meisner;F. Pinkerton;M. Balogh
中科院分区：
文献类型：
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作者：
Y. Filinchuk;K. Yvon;G. Meisner;F. Pinkerton;M. Balogh
四元金属氢化物在组成LiB(0.33)N(0.67)H（2.67）附近的单晶x射线数据表明，它的真实组成是Li4BN3H10。该结构具有体心立方对称[空间群I2(1)3，胞参数a = 10.679(1)-10.672(1)埃]，并包含BH4-和NH2-阴离子按摩尔比1:3有序排列。硼氢化物阴离子具有几乎理想的四面体几何形状（角h - b - h约为108-114度），而酰胺阴离子具有接近四面体的键角（角h - n - h约为106度）。三个不对称的Li原子位置被BH4-和NH2-阴离子以各种扭曲的四面体构型包围，一个被两个B和两个N原子包围，另一个被四个N原子包围，第三个被一个B和三个N原子包围。Li在B周围的构型接近四面体，而在N周围的构型类似于扭曲的鞍状构型，分别类似于LiBH4和LiNH2。
X-ray data on single crystals of the quaternary metal hydride near the composition LiB(0.33)N(0.67)H(2.67), previously identified as "Li3BN2H8", reveal that its true composition is Li4BN3H10. The structure has body-centered-cubic symmetry [space group I2(1)3, cell parameter a = 10.679(1)-10.672(1) Angstroms] and contains an ordered arrangement of BH4- and NH2- anions in the molar ratio 1:3. The borohydride anion has an almost ideal tetrahedral geometry (angleH-B-H approximately 108-114 degrees), while the amide anion has a nearly tetrahedral bond angle (angleH-N-H approximately 106 degrees). Three symmetry-independent Li atom sites are surrounded by BH4- and NH2- anions in various distorted tetrahedral configurations, one by two B and two N atoms, another by four N atoms, and the third by one B and three N atoms. The Li configuration around B is nearly tetrahedral, while that around N resembles a distorted saddlelike configuration, similar to those in LiBH4 and LiNH2, respectively.