TOPOS 3.1 – program package for multipurpose geometrical and topological analysis of crystal structures

Dietrich

Janek

et al. 2017

Li P N was synthesized by reaction of LiPN and Li PN 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 Li N flux enabled a complete structure determination using single-crystal X-ray diffraction. The hitherto unknown tricyclic [P N ] anion is composed of six vertex-sharing PN tetrahedra forming one vierer- and two additional dreier-rings. To confirm the structure, Rietveld refinement, Li and P 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.

Section: Resultsmentioning

confidence: 99%

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

Dietrich

Janek

et al. 2017

“…To confirm the possible movement of the Li + ions, possible voids and migration pathways were analyzed with TOPOS . Calculating the Voronoi–Dirichlet polyhedra leads to possible migration pathways.…”

Section: Resultsmentioning

confidence: 99%

“…LiPN 2 , Li 7 PN 4 , and β‐Li 10 P 4 N 10 were synthesized by reaction of Li 3 N (Rockwood Lithium, 94 %) and P 3 N 5 (LiPN 2 : molar ratio 1.2:1; Li 7 PN 4 : 7.2:1; β‐Li 10 P 4 N 10 : 2.8:1) in sealed silica ampoules under Ar atmosphere. The starting materials were ground and transferred into a Ta‐crucible, which was placed in a dried silica tube.…”

Section: Methodsmentioning

confidence: 99%

Reversible Polymerization of Adamantane‐type [P₄N₁₀]¹⁰⁻ Anions to Honeycomb‐type [P₂N₅]⁵⁻ Layers under High‐Pressure

Niklaus

Schnick

2017

The high-pressure polymorph Li P N of Li P N (="2 Li P N ") was synthesized by high-pressure/high-temperature reaction of LiPN and Li PN or β-Li P N at 9 GPa, using the Li N self-flux method in a Walker-type multianvil assembly. Li P N is the first lithium nitridophosphate with a layered structure and is made up of corner sharing PN tetrahedra forming a corrugated honeycomb-type layer of linked sechser-rings in chair conformation. The arrangement of the P atoms is analogous to that of black phosphorus. The structure was elucidated from single-crystal X-ray data. To confirm the structure Rietveld refinement, Li, Li and P solid-state NMR spectroscopy were conducted. To corroborate Li P N as the corresponding high-pressure polymorph of β-Li P N DFT calculations and temperature dependent X-ray powder diffraction were carried out. DFT calculations estimated the transition pressure to 6.5 GPa (without accounting for temperature), which is in line with the synthesis pressure.

“…[24,[44][45][46][47] b-Li 10 P 4 N 10 ,L i 13 P 4 N 10 Cl 3 ,a nd Li 13 P 4 N 10 Br 3 show possible pathways in three different directions in space and seem to be promising candidates for lithium ion conductivity in terms of their structuralp roperties (Supporting Information, Figures S41-S43). Through these calculations, we additionally confirmed the positions of the Li + ions found during structure determination.…”

Section: Structural Analysis Of Possible Lithiumm Igration Pathwaysmentioning

confidence: 99%

Li⁺ Ion Conductors with Adamantane‐Type Nitridophosphate Anions β‐Li₁₀P₄N₁₀ and Li₁₃P₄N₁₀X₃ with X=Cl, Br

Dietrich

Leichtweiß

et al. 2017

b-Li 10 P 4 N 10 and Li 13 P 4 N 10 X 3 with X = Cl, Br have been synthesized from mixtures of P 3 N 5 ,L i 3 N, LiX,L iPN 2 ,a nd Li 7 PN 4 at temperatures below 850 8C. b-Li 10 P 4 N 10 is the lowtemperature polymorph of a-Li 10 P 4 N 10 and crystallizes in the trigonal space group R3. It is made up of non-condensed [P 4 N 10 ] 10À T2 supertetrahedra, whicha re arrangedi ns phalerite-analogous packing. Li 13 P 4 N 10 X 3 (X = Cl, Br) crystallizes in the cubic space group Fm " 3m.B oth isomorphic compounds comprise adamantane-type [P 4 N 10 ] 10À ,L i + ions, and halides, which form octahedra. These octahedra build up af ace-centered cubic packing,w hose tetrahedral voids are occupied by the [P 4 N 10 ] 10À ions. The crystal structures have been elucidated from X-ray powder diffraction data and corroborated by EDX measurements, solid-state NMR, and FTIR spectroscopy.F urthermore,w eh ave examined the phase transition between a-a nd b-Li 10 P 4 N 10 .T oc onfirm the ionic character, the migration pathways of the Li + ions have been evaluated and the ion conductivity and its temperature dependence have been determined by impedance spectroscopy.X PS measurementsh aveb een carriedo ut to analyze the stability with respect to Li metal.