Photochemistry of benzene and oxygen in supersonic cluster beams

A reaction is seen to occur between benzene and oxygen in a supersonic beam when mixed clusters are irradiated by 193nm. This reaction has been investigated by multiphoton ionization mass spectrometry, with primary reaction products including the introduction of up to four oxygen atoms onto the benzene, as well as species resulting from hydrogen abstraction. A two laser experiment indicates that the initial step in the photochemical reaction results in a neutral species which lives for longer than 100 ..mu..s.