TY - JOUR
T1 - Detection of OH stretching mode of CH3OH chemisorbed on Ni 3+ and Ni4+ by infrared photodissociation spectroscopy
AU - Hirabayashi, Shinichi
AU - Okawa, Ryuji
AU - Ichihashi, Masahiko
AU - Kondow, Tamotsu
AU - Kawazoe, Yoshiyuki
PY - 2007/8/9
Y1 - 2007/8/9
N2 - Structures of nickel cluster ions adsorbed with methanol, Ni 3+(CH3OH)m (m = 1-3) and Ni 4+(CH3OH)m (m = 1-4) were investigated by using infrared photodissociation (IR-PD) spectroscopy based on a tandem-type mass spectrometer, where they were produced by passing Ni 3,4+ through methanol vapor under a multiple collision condition. The IR-PD spectra were measured in the wavenumber region between 3100 and 3900 cm-1. In each IR-PD spectrum, a single peak was observed at a wavenumber lower by ∼40 cm1 than that of the OH stretching vibration of a free methanol molecule and was assigned to the OH stretching vibrations of the methanol molecules in Ni3,4+(CH 3OH)m. The photodissociation was analyzed by assuming that Ni3,4 +(CH3-OH)m dissociate unimolecularly after the photon energy absorbed by them is statistically distributed among the accessible modes of Ni3,4+(CH 3OH)m. In comparison with the calculations performed by the density functional theory, it is concluded that (1) the oxygen atom of each methanol molecule is bound to one of the nickel atoms in Ni3,4 + (defined as molecular chemisorption), (2) the methanol molecules in Ni3,4+(CH3OH)m do not form any hydrogen bonds, and (3) the cross section for demethanation [CH4 detachment from Nin+(CH3-OH)] is related to the electron density distribution inside the methanol molecule.
AB - Structures of nickel cluster ions adsorbed with methanol, Ni 3+(CH3OH)m (m = 1-3) and Ni 4+(CH3OH)m (m = 1-4) were investigated by using infrared photodissociation (IR-PD) spectroscopy based on a tandem-type mass spectrometer, where they were produced by passing Ni 3,4+ through methanol vapor under a multiple collision condition. The IR-PD spectra were measured in the wavenumber region between 3100 and 3900 cm-1. In each IR-PD spectrum, a single peak was observed at a wavenumber lower by ∼40 cm1 than that of the OH stretching vibration of a free methanol molecule and was assigned to the OH stretching vibrations of the methanol molecules in Ni3,4+(CH 3OH)m. The photodissociation was analyzed by assuming that Ni3,4 +(CH3-OH)m dissociate unimolecularly after the photon energy absorbed by them is statistically distributed among the accessible modes of Ni3,4+(CH 3OH)m. In comparison with the calculations performed by the density functional theory, it is concluded that (1) the oxygen atom of each methanol molecule is bound to one of the nickel atoms in Ni3,4 + (defined as molecular chemisorption), (2) the methanol molecules in Ni3,4+(CH3OH)m do not form any hydrogen bonds, and (3) the cross section for demethanation [CH4 detachment from Nin+(CH3-OH)] is related to the electron density distribution inside the methanol molecule.
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U2 - 10.1021/jp072548z
DO - 10.1021/jp072548z
M3 - Article
C2 - 17602542
AN - SCOPUS:34548040714
VL - 111
SP - 7664
EP - 7669
JO - Journal of Physical Chemistry A
JF - Journal of Physical Chemistry A
SN - 1089-5639
IS - 31
ER -