Structure, Thermodynamic and Electronic Properties of Carbon-Nitrogen Cubanes and Protonated Polynitrogen Cations

TL;DR

This study uses quantum chemistry to explore the stability, properties, and energy potential of carbon-nitrogen cubanes and polynitrogen cations, revealing their promise as high-energy materials with specific stability and energy release characteristics.

Contribution

It provides new insights into the stability, energetic properties, and potential synthesis pathways of nitrogen-rich cubanes and polynitrogen cations for energetic applications.

Findings

Nitrogen content increases stored energy in cubanes.

Nitrogen-poor cubanes are stable in vacuum.

Polynitrogen cations release large energy upon decomposition.

Abstract

Energy generation and storage are at the center of modern civilization. Energetic materials constitute quite a large class of compounds with a high amount of stored chemical energy that can be released. We hereby use a combination of quantum chemistry methods to investigate feasibility and properties of carbon-nitrogen cubanes and multi-charged polynitrogen cations in the context of their synthesis and application as unprecedented energetic materials. We show that the stored energy increases gradually with the nitrogen content increase. Nitrogen-poor cubanes retain their stabilities in vacuum, even at elevated temperatures. Such molecules will be probably synthesized at some point. In turn, polynitrogen cations are highly unstable, except N8H+, despite they are isoelectronic to all-carbon cubane. Kinetic stability of the cation decays drastically as its total charge increases. High-level thermodynamic calculations revealed that large amounts of energy are liberated upon decompositions of polynitrogen cations, which produce molecular nitrogen, acetylene, and protons. The present results bring a substantial insights to the design of novel high energy compounds.