C10H7

C10H7 is the molecular formula associated with several hydrocarbon species, most notably the naphthyl radical derived from naphthalene (C10H8) by hydrogen abstraction. There is no single neutral closed-shell hydrocarbon with this formula; the neutral form is a radical.

The two major isomeric forms are the 1-naphthyl radical and the 2-naphthyl radical, depending on the site of hydrogen removal from naphthalene. Other C10H7 radicals may exist from different polycyclic aromatic hydrocarbon (PAH) derivatives.

These species are planar polycyclic aromatic systems with conjugated π electrons. The unpaired electron in C10H7 is delocalized over the fused rings but is localized near the hydrogen vacancy, giving characteristic spin-density distributions observed in spectroscopic studies.

They are studied as reactive intermediates in combustion chemistry and atmospheric chemistry. C10H7 radicals are detected in gas-phase experiments and via techniques such as mass spectrometry and electron paramagnetic resonance (EPR) spectroscopy. Through radical-radical and radical-molecule reactions, they can participate in growth processes that lead to the formation of larger PAHs and, in some environments, soot precursors.

Notes: The formula C10H7 also encompasses charged or radical species such as C10H7+ or C10H7− in spectroscopic and mass-spectrometric studies. The neutral, closed-shell molecule with this exact composition is not stable under simple hydrocarbon valence constraints, so C10H7 is used primarily to describe radical or ionic forms related to naphthalene derivatives.