C13H9N

C13H9N is the molecular formula that describes a class of nitrogen-containing polycyclic aromatic hydrocarbons (N-PAHs). Because it contains one nitrogen atom and thirteen carbons, this formula corresponds to several distinct constitutional isomers, all of which are polycyclic and highly unsaturated.

Two well-known isomers with this formula are acridine and phenanthridine. Acridine features a tri-cyclic, linearly fused ring system with a ring nitrogen in the central position; phenanthridine has a similar three-ring framework with the nitrogen incorporated in one ring. Other isomers exist as different arrangements of nitrogen within fused benzene rings, all sharing the same empirical formula.

These compounds are typically planar and exhibit the properties typical of heteroaromatic systems: the ring nitrogen can impart basicity, and the fused aromatic framework endows them with stability and notable electronic delocalization. They are generally soluble in many organic solvents and can participate in pi-stacking, intercalation, and other interactions relevant to dyes and electronic materials. In research contexts, acridine and related N-PAHs are studied as fluorescent probes, intercalating agents for DNA, and components in organic electronics or photonics.

Occurrence and synthesis: They form part of the broader family of PAHs and aza-PAHs investigated in organic chemistry and materials science. Many are prepared through condensation and cyclization routes from simpler precursors, with structural variations introduced to tune electronic and optical properties.

Safety: Like many polycyclic aromatic compounds, some nitrogen-containing PAHs can be toxic or potentially carcinogenic. Appropriate safety precautions, handling, and waste disposal practices are essential when working with these substances.