Aromatic carboxylic acids are produced by reacting a Lewis acid: CO2 complex with aromatic hydrocarbons. The complex can be created by incubating a Strong Lewis acid and CO2 and forming a composition consisting essentially of CO2, strong Lewis acid, and Lewis acid: CO2 complex. Carboxylation of aromatic hydrocarbons to produce aromatic carboxylic acids using the composition and method in accordance with this invention provides improved yields without the use of finely divided aluminum or zinc.