LAUSR

Abstract Applying computational methods for predicting gas-phase O H stretch overtone spectra to the series of fluorinated hydroperoxides CF 3 OOH, CHF 2 OOH, and CH 2 FOOH reveals how intramolecular hydrogen bonding changes their overtone photochemistry, relative to their un-fluorinated analog CH 3 OOH. Intramolecular hydrogen bonding between fluorine and the hydroxyl hydrogen atom decreases O H stretch frequencies and raises the barrier for torsion about the O O bond. Whereas O O torsion accompanies O H stretch overtone excitation for CH 3 OOH, this is not the case for the fluorinated analogs that have intramolecular hydrogen bonding. The comparison highlights the molecular features that contribute to the feasibility of atmospheric overtone-induced O O bond dissociation for CH 3 OOH, but not for its fluorinated analogs.