title: OH-stretch vibrational spectroscopy of hydroxymethyl hydroperoxide.
abstract: We report measurement and analysis of the photodissociation spectrum of hydroxymethyl hydroperoxide (HOCH(2)OOH) and its partially deuterated analogue, HOCD(2)OOH, in the OH-stretching region. Spectra are obtained by Fourier transform infrared spectroscopy in the 1nu(OH) and 2nu(OH) regions, and by laser induced fluorescence detection of the OH fragment produced from dissociation of HOCH(2)OOH initiated by excitation of the 4nu(OH) and 5nu(OH) overtone regions (action spectroscopy). A one-dimensional local-mode model of each OH chromophore is used with ab initio calculated OH-stretching potential energy and dipole moment curves at the coupled-cluster level of theory. Major features in the observed absorption and photodissociation spectra are explained by our local-mode model. In the 4nu(OH) region, explanation of the photodissocation spectrum requires a nonuniform quantum yield, which is estimated by assuming statistical energy distribution in the excited state. Based on the estimated dissociation threshold, overtone photodissociation is not expected to significantly influence the atmospheric lifetime of hydroxymethyl hydroperoxide.
authors.affiliation: Arthur Amos Laboratory of Chemical Physics, California Institute of Technology, Pasadena, 91125, USA.
authors.forename: Juliane L
authors.initials: JL
authors.lastname: Fry
authors.forename: Jamie
authors.initials: J
authors.lastname: Matthews
authors.forename: Joseph R
authors.initials: JR
authors.lastname: Lane
authors.forename: Coleen M
authors.initials: CM
authors.lastname: Roehl
authors.forename: Amitabha
authors.initials: A
authors.lastname: Sinha
authors.forename: Henrik G
authors.initials: HG
authors.lastname: Kjaergaard
authors.forename: Paul O
authors.initials: PO
authors.lastname: Wennberg