The Shape of Three-Coordinate Nitrogen Cages

Abstract

Complex forms of nitrogen are of scientific interest for their energetic properties.  A number of different forms of nitrogen have been the subject of experiment and/or theoretical studies.  One such form is the three-coordinate cage, some of which are a nitrogen-based analogue to the well-known carbon fullerenes.  Such cages N_x would decompose by N_x → (x/2) N₂, with the release of substantial amounts of energy.  A study of N₂₀ cages, one of which is the analogue of the smallest fullerene C₂₀, revealed that the pentagon-hexagon network favored by carbon is NOT favored by nitrogen.  Other cages, based on other polygons, are more thermodynamically stable for nitrogen.  In this review, multiple studies of the properties of nitrogen cages are considered and trends regarding structure and energy are discussed.