Ultraviolet photolysis of anthracene in H2O interstellar ice analogs: Potential connection to meteoritic organics

Abstract

The polycyclic aromatic hydrocarbon (PAH) anthracene was oxidized by exposure to ultraviolet (UV) radiation in H2O ice under simulated astrophysical conditions, forming several anthracene ketones (9-anthrone, 1,4-anthraquinone, and 9,10-anthraquinone) and alcohols (1-anthrol and 2-anthrol). Two of the ketones produced have been detected in the Murchison meteorite but, to our knowledge, there has been no search for the alcohols or other oxidized anthracenes in meteorites. These results seem consistent with the possibility that interstellar ice photochemistry could have influenced the inventory of aromatics in meteorites. Since quinones are also fundamental to biochemistry, their formation in space and delivery to planets is relevant to studies relating to the habitability of planets and the evolution of life. © The Meteoritical Society, 2007.