# Mechanism for Ce(IV) Oxidation of Naphthalene

S. Cotton's Lanthanide and Actinide Chemistry reports that naphthalene can be oxidized to naphthalene-1,4-dione using cerric ammonium sulfate (CAS), $$\ce{MeCN, H2SO4},$$ and $$\ce{H2O}$$.1 No mechanism was provided, and I was unable to find a complete mechanism for this transformation in the literature. From what I did find, Love et al.2 have reported the first step of this mechanism is the formation of the radical cation while the second step is the attack of a water molecule. After these two steps, the authors of the paper do not give any further information. I proposed a mechanism below, but I have a few concerns. To start, why is sulfuric acid used when protons seem to be lost during the transformation? I assume this is to prevent the cerium from reacting with the water to form hydroxides as it can be quite basic, but it is nonetheless unsettling.

References:

1Simon Cotton, In Lanthanide and Actinide Chemistry; Inorganic Chemistry, A Wiley Textbook Series, John Wiley & Sons, Ltd: Chichester, England, 2006 (ISBN-13: 978-0-470-01005-1).

2Brian E. Love, Alexander L. Simmons, "Substituent Effects in the Oxidation of 2-Alkyl-1,4-dialkoxybenzenes with Ceric Ammonium Nitrate," Tetrahedron Lett. 2016, 57(50), 5712-5715 (DOI: https://doi.org/10.1016/j.tetlet.2016.11.042).