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


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

JOURNAL OF PHYSICAL CHEMISTRY A, cilt.114, ss.5104-5112, 2010 (SCI İndekslerine Giren Dergi) identifier identifier

  • Cilt numarası: 114 Konu: 15
  • Basım Tarihi: 2010
  • Doi Numarası: 10.1021/jp100565k
  • Dergi Adı: JOURNAL OF PHYSICAL CHEMISTRY A
  • Sayfa Sayıları: ss.5104-5112

Özet

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.