Thermolysis of the Benzophenone Ketyl

Benzophenone, a material that is common in biomass and coal, resists pyrolysis up to 400 °C. However, when the compound is reduced with potassium metal in tetrahydrofuran (THF) followed by solvent removal, the C−H bonds, as well as the CO bond, are activated, and the solid K+C12H10CO•–·THF salt begins to gasify at less than 250 °C. The noncondensable (at liquid nitrogen temperature) gases consist of hydrogen and methane. Condensable pyrolysis products include the following: benzene, toluene, biphenyl, xylenes, diphenylmethane, and ethylbenzene. When the temperature is raised to 380 °C and held there for several hours, CO is also liberated. Isotopic labeling studies suggest that the CH4 comes from a carbene intermediate, and the CO does not originate from the carbonyl moiety of the ketyl.