ABSTRACT

The photochemistry of biacetyl has been of popular interest since the 1950’s. Research regarding the photochemistry of biacetyl has been done in the gas, liquid, and solid phase. Irradiation of biacetyl trapped in an inert gas matrix allows for observation of the unstable photoproducts, which were identified using infrared spectroscopy. Pulsed laser excitation (338nm) of biacetyl in an oxygen matrix does not produce the expected products from irradiation (ketene, acetyl, and methyl hydroxycarbene). For this experiment, the ketene product is only observed in the oxygen matrix after irradiation using the filtered output of mercury vapor lamp. Continuous irradiation at wavelengths less than 450nm was necessary to produce the ketene product. In other matrices, such as nitrogen, products are formed and observed from the pulsed laser light source (338nm) combined with the mercury vapor lamp with wavelengths exceeding 550 nm. The lack of product observed in the oxygen matrix can be explained by quenching.