In Situ Hydrogenation of the Zintl Phase SrGe

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• 作者：Henry AuerDirk Wallacher ; Thomas Christian Hansen ; Holger Kohlmann
• 刊名：Inorganic Chemistry
• 出版年：2017
• 出版时间：February 6, 2017
• 年：2017
• 卷：56
• 期：3
• 页码：1072-1079
• 全文大小：497K
• ISSN：1520-510X

文摘

Hydrides (deuterides) of the CrB-type Zintl phases AeTt (Ae = alkaline earth; Tt = tetrel) show interesting bonding properties with novel polyanions. In SrGeD_4/3–x (γ phase), three zigzag chains of Ge atoms are condensed and terminated by covalently bound D atoms. A combination of in situ techniques (thermal analysis and synchrotron and neutron powder diffraction) revealed the existence of two further hydride (deuteride) phases with lower H (D) content (called α and β phases). Both are structurally related to the parent Zintl phase SrGe and to the ZrNiH structure type containing variable amounts of H (D) in Sr₄ tetrahedra. For α-SrGeD_y, the highest D content y = 0.29 was found at 575(2) K under 5.0(1) MPa of D₂ pressure, and β-SrGeD_y shows a homogeneity range of 0.47 < y < 0.63. Upon decomposition of SrGeD_4/3–x (γ-SrGeD_y), tetrahedral Sr₄ voids stay filled, while the Ge-bound D4 site loses D. When reaching the lower D content limit, SrGeD_4/3–x (γ phase) with 0.10 < x < 0.17, decomposes to the β phase. All three hydrides (deuterides) of SrGe show variable H (D) content.