C12N

C12N is a chemical formula used to denote a class of carbon-nitrogen species containing 12 carbon atoms and one nitrogen atom. It does not refer to a single, well-defined molecule; rather, it encompasses many possible isomers and charge states, and in neutral form a stable, closed-shell C12N compound is not generally established. Because carbon tends to form four bonds and nitrogen three (or five in certain charge states), most studied realizations are ions or hydrogen-terminated derivatives.

Structures proposed for C12N include nitrogen substituted into polycyclic aromatic frameworks (where a single N atom replaces a CH group in a PAH-like core), nitrogen-doped small graphitic fragments (a nanographene piece with one N dopant), and compact ring systems with one nitrogen atom embedded in a carbon skeleton. The actual geometry depends on the site of nitrogen incorporation and on whether the species carries a positive or negative charge.

Synthesis and detection of C12N species are challenging. Neutral, isolated C12N molecules are not common targets, but related charged clusters can be observed in mass spectrometry or produced in high-energy environments such as plasma processes or combustion. In astrochemistry, carbon-nitrogen clusters are of interest for understanding molecular formation pathways in space.

Properties of C12N are highly dependent on isomer and charge state; theoretical studies explore potential aromatic stabilization, electronic structure, and reactivity. C12N thus serves mainly as a conceptual marker in discussions of carbon-nitrogen chemistry and as a reference point for larger nitrogen-doped carbon systems.

See also: polycyclic aromatic nitrogen heterocycles, nitrogen-doped carbon materials, carbon nitride.