A novel square planar N42- ring with aromaticity in BeN4

A structural search leads to the prediction of a novel alkaline earth nitride BeN4 containing a square planar N-4(2-) ring. This compound has a particular chemical bonding pattern giving it potential as a high-energy-density material. The P4/nmm phase of BeN4 may be stable under ambient conditions, with a bandgap of 3.72 eV. It is predicted to have high thermodynamic and kinetic stability due to transfer of the outer-shell s electrons of the Be atom to the N-4 cluster, with the outer-shell 2p orbital accommodating the lone-pair electrons of N-4(2-). The total of six pi electrons is the most striking feature, indicating that the square planar N-4(2-) exhibits aromaticity. Under ambient conditions, BeN4 has a high energy density (3.924 kJ/g relative to Be3N2 and N-2 gas), and its synthesis might be possible at pressures above 31.6 GPa.(c) 2022 Author(s).All article content, except where otherwise noted, is licensed under a Creative Commons Attribution (CC BY)license (http://creativecommons.org/licenses/by/4.0/).

Automated summary

A structural search predicts the existence of a novel alkaline earth nitride, BeN4, with a square planar N-4(2-) ring. This compound exhibits a unique chemical bonding pattern and has potential as a high-energy-density material.