Abstract:

We report the infrared spectra and ultraviolet photolysis of beta- and gamma-butyrolactone trapped in solid nitrogen and argon matrices.

The infrared spectrum of beta-butyrolactone is in agreement with DFT results. The photoproducts were characterized via infrared spectroscopy. Irradiation at wavelengths below 250 nm resulted in the production of ketene and acetaldehyde. There is also evidence of a secondary photolysis that produces atomic oxygen. Ab initio calculations were used to evaluate potential decomposition mechanisms.

The vibrational assignments for gamma-butyrolactone differ slightly from the liquid results obtained by McDermott. Irradiation at wavelengths below 250 nm results in the production of CO and CO₂. There is also evidence of a secondary photolysis that produces atomic oxygen.

Possible mechanisms of photolysis were evaluated base on observed photoproducts and ab initio calculations.