The amphoteric role of nitrogen in the NX2 unit within crystals

Abstract

Hirshfeld atom refinement studies of hexachloro-cyclo-triphosphazene against high-resolution experimental data revealed the possibility of nitrogen acting simultaneously as a donor and acceptor in interactions with chlorine atoms, resulting in an NCl₂ unit equivalent to the X₃ synthon reported for halogen (X) bonding. This paper describes the scenarios for the NCl₂ unit found in crystals, its stability analysis, and the donor–acceptor features for each case. A similar analysis is also performed for NBr₂ and NI₂.