Ketone, Radical Cation and Its Decomposition. Part 2: The structure of 2-hexanone radical cation.
There is hardly any noticable change in structure associated with the ionization of 2-hexanone. The ionization takes an electron away from one of the non-bonding oxygen lone pairs. In fact, the ionization causes a contraction of the oxygen atom and the CO bond becomes a tiny bit shorter. The CO bond lengths in the ketone and its radical cation are 122.7 and 121.7 pm.