Ã-X absorption of propargyl peroxy radical (H-C≡C-CH2OO·): a cavity ring-down spectroscopic and computational study.
The Ã-X electronic absorption spectrum of propargyl peroxy radical has been recorded at room temperature by cavity ring-down spectroscopy. Electronic structure calculations predict two isomeric forms, acetylenic and allenic, with two stable conformers for each. The acetylenic trans conformer, with a band origin at 7631.8 ± 0.1 cm(-1), is definitively assigned on the basis of ab initio calculations and rotational simulations, and possible assignments for the acetylenic gauche and allenic trans forms are given. A fourth form, allenic cis, is not observed. Simulations based on calculated torsional potentials predict that the allenic trans form will have a long, poorly resolved progression in the OOCC torsional vibration, consistent with experimental observations.
Department of Chemistry, The Ohio State University, 120 West 18th Avenue, Columbus, Ohio 43210, USA.
Phillip S
PS
Thomas
Neal D
ND
Kline
Terry A
TA
Miller