Li47 B3 P14 N42 -A Lithium Nitridoborophosphate with [P3 N9 ]12- , [P4 N10 ]10- , and the Unprecedented [B3 P3 N13 ]15- Ion

Abstract

Li₄₇ B₃ P₁₄ N₄₂ , the first lithium nitridoborophosphate, is synthesized by two different routes using a Li₃ N flux enabling a complete structure determination by single-crystal X-ray diffraction data. Li₄₇ B₃ P₁₄ N₄₂ comprises three different complex anions: a cyclic [P₃ N₉ ]^12- , an adamantane-like [P₄ N₁₀ ]^10- , and the novel anion [P₃ B₃ N₁₃ ]^15- . [P₃ B₃ N₁₃ ]^15- is the first species with condensed B/N and P/N substructures. Rietveld refinement, ⁶ Li, ⁷ Li, ¹¹ B, and ³¹ P solid-state NMR spectroscopy, FTIR spectroscopy, EDX measurements, and elemental analyses correspond well with the structure model from single-crystal XRD. To confirm the mobility of Li⁺ ions, their possible migration pathways were evaluated and the temperature-dependent conductivity was determined by impedance spectroscopy. With the Li₃ N flux route we gained access to a new class of lithium nitridoborophosphates, which could have a great potential for unprecedented anion topologies with interesting properties.

Keywords: borophosphates; conductivity; lithium; nitrides; solid-state structures.