Vibrational Spectroscopy of Intermediates in Methane-to-Methanol Conversion by FeO+


Altinay G., Citir M., Metz R. B.

JOURNAL OF PHYSICAL CHEMISTRY A, vol.114, no.15, pp.5104-5112, 2010 (Journal Indexed in SCI) identifier identifier

  • Publication Type: Article / Article
  • Volume: 114 Issue: 15
  • Publication Date: 2010
  • Doi Number: 10.1021/jp100565k
  • Title of Journal : JOURNAL OF PHYSICAL CHEMISTRY A
  • Page Numbers: pp.5104-5112

Abstract

Gas phase FeO+ can convert methane to methanol under thermal conditions. Two key intermediates of this reaction are the [HO−Fe−CH3]+ insertion intermediate and Fe+(CH3OH) exit channel complex. These intermediates are selectively formed by reaction of laser-ablated Fe+ with organic precursors under specific source conditions and are cooled in a supersonic expansion. Vibrational spectra of the sextet and quartet states of the intermediates in the O−H and C−H stretching regions are measured by infrared multiple photon dissociation of Fe+(CH3OH) and [HO−Fe−CH3]+ and by monitoring argon atom loss following irradiation of Fe+(CH3OH)(Ar) and [HO−Fe−CH3]+(Ar)n (n = 1, 2). Analysis of the experimental results is aided by comparison with hybrid density functional theory computed frequencies. Also, an improved potential energy surface for the FeO+ + CH4 reaction is developed based on CCSD(T) and CBS-QB3 calculations for the reactants, intermediates, transition states, and products.

Gas phase FeO+ can convert methane to methanol under thermal conditions. Two key intermediates of this reaction are the [HO-Fe-CH3](+) insertion intermediate and Fe+(CH3OH) exit channel complex. These intermediates are selectively formed by reaction of laser-ablated Fe+ with organic precursors under specific source conditions and are cooled in a supersonic expansion. Vibrational spectra of the sextet and quartet states of the intermediates in the O-H and C-H stretching regions are measured by infrared multiple photon dissociation of Fe+(CH3OH) and [HO-Fe-CH3](+) and by monitoring argon atom loss following irradiation of Fe+(CH3OH)(Ar) and [HO-Fe-CH3](+)(Ar)(n) (n = 1, 2). Analysis of the experimental results is aided by comparison with hybrid density functional theory computed frequencies. Also, an improved potential energy surface for the FeO- + CH4 reaction is developed based on CCSD(T) and CBS-QB3 calculations for the reactants, intermediates, transition states, and products.