Frequency Doubled CO₂ Laser Induced Decomposition of Carbonyl Compounds: Cyclobutanone

Abstract

This paper reports the first use of radiation derived from a TEA carbon dioxide laser by nonlinear upshifting techniques (second harmonic generation) in initiating multiphoton absorption and dissociation. The frequency doubled CO₂ laser has frequency coverage from 2180–1750 cm^–1. This frequency region is of importance as it allows pumping of the fundamental stretching modes of organic carbonyl groups (anhydrides, acyl chlorides and strained cyclic ketones), inorganic carbonyl groups, and carbontritium bonds. The laser has been used to excite cyclobutanone in the region of the carbonyl stretch. Efficient multiphoton absorption and two channel dissociation are observed. The product array is consistent with that observed upon excitation at 10 μm.