F+:Highly flammable;74-82-8Relevant articles and documents
Kinetics of the reaction of O2+ with CH4 from 500 to 1400 K: A case for state specific chemistry
Dotan,Viggiano
, p. 6112 - 6118 (2007/10/03)
The temperature dependent rate constants and branching ratios for the reaction of O2+ with CH4 and O2 with CD4 from 500 to 1400 K were determined. By comparing to previous studies, the influence on vibrational excitation in the CH4 reactant was derived.
Dissociation dynamics of CH4+ core ion in the 2A1 state
Furuya, Kenji,Kimura, Katsumi,Sakai, Yasuhiro,Takayanagi, Toshinobu,Yonekura, Nobuaki
, p. 2720 - 2728 (2007/10/02)
Threshold-photoelectron photoion coincidence (TPEPICO) spectra of CH4 have been observed with synchrotron radiation at the excitation to the 2A1 (υ1=0-3) ionic states as well as to the 4pt2 Rydberg (υ1 = 0-4) states.In all the TPEPICO spectra observed, the CH3+ band shape was almost rectangular, which suggests that the translational and internal energy distributions of CH3+ are very narrow.The total kinetic energy releases (KERs) have been estimated from the CH3+ band shape.As a result, it was found that the CH3+ species were in an electronically excited state.There was a narrow distribution of the total KERs and similarity in the TPEPICO CH3+ band shapes between the spectra at the 2A1 ionic state and the 4pt2 Rydberg state excitations, which led to the conclusion that the Rydberg electron is just a spectator and the dissociation of the core ion plays an important role in dissociation through the 4pt2 Rydberg state.Similar results have also been obtained for CH2+ and CH+ productions.However, on the other hand, an H+ fragment has been observed only at the 2A1 state excitation.It showed a band with a long tail in the slower flight time region.The total average KERs and the decay rates have been estimated from band shape simulation.From these results, it has been found that a dissociation limit of the H+ ion exists just below the 2A1 ionic state.The dissociation mechanisms through the 4pt2 Rydberg state have been discussed in detail in comparison with those of the 2A1 ionic state.
Competitive reaction and quenching of vibrationally excited O2+ ions with SO2, CH4, and H2O
Durup-Ferguson, M.,Boehringer, H.,Fahey, D. W.,Fehsenfeld, F. C.,Ferguson, E. E.
, p. 2657 - 2666 (2007/10/02)
Vibrationally excited O2+ ions injected into a He buffered flow tube react rapidly with SO2 and H2O by charge transfer and with CH4 to produce CH3O2+, CH3+, and CH4+.It is found that the rapidly reacting states at thermal energy are O2+ (ν2) for SO2 and CH4 and O2+(ν3) for H2O, while the lower vibrationally excited states are rapidly quenched.When the reactions of SO2 and CH4 are studied in Ar buffer as a function of kinetic energy it is found that the vibrational temperature of Oz established through collisional excitation by the Ar buffer is perturbed by quenching collisions with the reactant molecules.This leads to observed reaction rate constants that change with reactant gas concentration.For the reaction of O2+ with CH4 the influence of kinetic and vibrational energy on the branching ratio of the reaction channels has been investigated.The present vibrational relaxation data for O2+(ν) by CH4, in conjunction with other recent measurements, allows a rather detailed picture of the mechanism to be drawn for this complicated reaction that involves the making and breaking of four chemical bonds.
