Rotational spectral studies of O( 1 D) insertion reactions with methane and ethylene: Methanol and vinyl alcohol in a supersonic expansion

Abstract We report a new apparatus for millimeter/submillimeter spectroscopic studies of O( 1 D) insertion reactions to produce molecules of astrophysical interest. This study focuses on the insertion of O( 1 D) into methane to form methanol, and the insertion of O( 1 D) into ethylene to form vinyl alcohol (CH 2 CHOH). The O( 1 D) was produced via laser photodissociation of O 3 in a fused silica tube and mixed with a hydrocarbon before a supersonic expansion. Direct absorption millimeter/submillimeter spectroscopy was used to monitor the products. The methanol study was used as an experimental benchmark, while the vinyl alcohol study extended rotational spectroscopic measurements to higher frequencies. Observed products from both insertion reactions included, but were not limited to, H 2 CO, HO 2 , and CH 3 O. Methanol and vinyl alcohol were only produced in detectable quantities when the fused silica tube was included, indicating that collisions before the expansion are required for production and stabilization of the O( 1 D) insertion products.