Li₁₈P₆N₁₆—A Lithium Nitridophosphate with Unprecedented Tricyclic [P₆N₁₆]^18− Ions

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• 作者：Eva-Maria Bertschler ; Christian Dietrich ; Prof. Dr. Jü ; rgen Janek and Prof. Dr. Wolfgang Schnick
• 刊名：Chemistry - A European Journal
• 出版年：2017
• 出版时间：February 10, 2017
• 年：2017
• 卷：23
• 期：9
• 页码：2185-2191
• 全文大小：994K
• ISSN：1521-3765

文摘

Li₁₈P₆N₁₆ was synthesized by reaction of LiPN₂ and Li₇PN₄ at 5.5 GPa and 1273 K employing the multi-anvil technique. It is the first lithium nitridophosphate obtained by high-pressure synthesis. Moreover, it is the first example received by reaction of two ternary lithium nitrides. The combination of high-pressure conditions with a Li₃N flux enabled a complete structure determination using single-crystal X-ray diffraction. The hitherto unknown tricyclic [P₆N₁₆]^18− anion is composed of six vertex-sharing PN₄ tetrahedra forming one vierer- and two additional dreier-rings. To confirm the structure, Rietveld refinement, ⁷Li and ³¹P solid-state NMR spectroscopy, FTIR spectroscopy and EDX measurements were carried out. To validate the ionic properties, the migration pathways of the Li⁺ ions were evaluated, and the conductivity and its temperature dependence were determined by impedance spectroscopy measurements. In order to obtain a clearer picture of the formation mechanism of this compound class, different synthetic approaches were compared, enabling targeted syntheses of unprecedented P/N-anion topologies with intriguing properties.