A careful scrutiny of the aromaticity in anionic polynitrogen clusters

The aromaticity of polynitrogen clusters plays a crucial role in defining their stability and potential applications in high-energy materials. In this study, we provide a comprehensive assessment of the aromatic character of N₄^2- and N₆^4- using a multifaceted approach that combines nucleus-independent chemical shift (NICS) analysis and the zz component of the magnetic shielding tensor. To further unravel the intricate electronic structures of these clusters, we employ state-of-the-art electronic descriptors, including the electron localization function (ELF) and adaptive natural density partitioning (AdNDP). Moreover, the propensity of these polynitrogen species for π-stacking interactions is meticulously evaluated using the Localized Orbital Locator Integrated Pi Over Plane (LOLIPOP) method. Our findings offer valuable insights into the fundamental electronic nature of polynitrogen clusters, shedding light on their stability and potential for supramolecular assembly.