How stable can the pentanitrogen cation be in kinetics?

Area of Science:

• * Computational chemistry
• * Inorganic chemistry
• * Theoretical chemistry

Background:

• * The pentanitrogen cation (N5+) is a nitrogen-rich compound with potential energetic applications.
• * Previous theoretical studies reported transition states (TSs) for N5+ decomposition, but these were inconsistent with experimental observations.
• * Discrepancies existed between the gas-phase and salt-like forms of N5+ regarding structure and energetics.

Purpose of the Study:

• * To accurately identify the transition states (TSs) for nitrogen molecule (N2) extrusion from the pentanitrogen cation (N5+).
• * To resolve the inconsistencies in the structural and energetic properties of N5+ between its gas-phase and salt-like forms.

Main Methods:

• * High-level computational chemistry methods were employed to investigate the potential energy surface of N5+.
• * The study focused on locating and characterizing the true N2-extrusion transition states.

Main Results:

• * The previously reported transition states for N5+ were found not to correspond to N2 extrusion.
• * The actual N2-extrusion transition state was successfully located.
• * The newly identified TS reconciles the structural and energetic differences between the gas-phase and salt-like N5+ forms.

Conclusions:

• * The accurate characterization of the N2-extrusion TS provides a unified understanding of N5+ behavior.
• * This finding resolves long-standing inconsistencies in the theoretical and experimental data for N5+.
• * The study offers crucial insights into the stability and reactivity of nitrogen-rich cations.