Anionic N₁₈ Macrocycles and a Polynitrogen Double Helix in Novel Yttrium Polynitrides YN₆ and Y₂N₁₁ at 100 GPa

Abstract

Two novel yttrium nitrides, YN6 and Y2N11, were synthesized by direct reaction between yttrium and nitrogen at 100 GPa and 3000 K in a laser‐heated diamond anvil cell. High‐pressure synchrotron single‐crystal X‐ray diffraction revealed that the crystal structures of YN6 and Y2N11 feature a unique organization of nitrogen atoms—a previously unknown anionic N18 macrocycle and a polynitrogen double helix, respectively. Density functional theory calculations, confirming the dynamical stability of the YN6 and Y2N11 compounds, show an anion‐driven metallicity, explaining the unusual bond orders in the polynitrogen units. As the charge state of the polynitrogen double helix in Y2N11 is different from that previously found in Hf2N11 and because N18 macrocycles have never been predicted or observed, their discovery significantly extends the chemistry of polynitrides.

Synthesis of LaCN3, TbCN3, CeCN5, and TbCN5 Polycarbonitrides at Megabar Pressures

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High-pressure reactions between the pnictogens: the rediscovery of BiN

“…Theoretical and experimental studies under extreme conditions have recently rejuvenated the interest in the chemistry of pnictogens and their compounds ( Young et al, 2006 ; Niwa et al, 2014 ; Wang et al, 2016 ; Laniel et al, 2018 ; Bykov et al, 2020 ; Laniel et al, 2022a ; Laniel et al, 2022b ; Aslandukov et al, 2022 ; Zhang et al, 2022 ). Each of the elements belonging to the nitrogen group is fascinating in its pure form; however, their compounds are equally important either for our everyday life or industry, and consequently, it results in an active multi-billion market either for raw and purified materials or compounds and derivatives.…”