High-pressure falloff curves and specific rate constants for the reactions atomic hydrogen + molecular oxygen .dblharw. perhydroxyl .dblharw. hydroxyl + atomic oxygen

1985 ◽  
Vol 89 (2) ◽  
pp. 342-349 ◽  
Author(s):  
C. J. Cobos ◽  
H. Hippler ◽  
J. Troe
Keyword(s):  
High Pressure ◽  
Molecular Oxygen ◽  
Rate Constants ◽  
Atomic Hydrogen ◽  
Atomic Oxygen ◽  
Specific Rate

The formation, reaction and deactivation of O 2 ( 1 Ʃ + g )

1968 ◽  
Vol 308 (1492) ◽  
pp. 81-94 ◽  
Keyword(s):  
Energy Transfer ◽  
Molecular Oxygen ◽  
Transfer Process ◽  
Rate Constants ◽  
Atomic Oxygen ◽  
Energy Transfer Process ◽  
Formation Reaction ◽  
Upper Limit ◽  
Excited Species ◽  
Energy Pooling

The paper describes an investigation of the reaction with ozone and the deactivation of O 2 ( 1 Ʃ + g ). A flow technique was employed, and O 2 ( 1 Ʃ + g ) was produced photochemically by the sequence of reactions: O 2 + hv (λ=1470Å) → O( 1 D ) + O( 3 P ), (4) O( 1 D ) + O 2 ( 3 Ʃ - g ) → O 2 ( 1 Ʃ + g ) + O( 3 P ). (5) The advantages achieved by this method of generation of the excited species are discussed. Rate constants were obtained for the reaction of O 2 ( 1 Ʃ + g ) with ozone, and for its quenching by N 2 , and an estimate is made of the efficiency of wall deactivation. An upper limit is suggested for the quenching of O 2 ( 1 Ʃ + g ) by molecular oxygen. The results are compared with those of earlier investigations, and the comparison is used to calculate the rate constant of the ‘energy-pooling’ reaction: O 2 ( 1 ∆ g ) + O 2 ( 1 ∆ g ) → O 2 ( 1 Ʃ + g ) + O 2 ( 3 Ʃ - g ). (1) Measurement of the concentrations of O 2 ( 1 Ʃ + g ) and of atomic oxygen formed on photolysis allows the efficiency of the energy transfer process (5) to be assessed relative to the efficiency of quenching by O 2 , N 2 or Ar. The several rate constants measured or estimated are tabulated at the end of the paper in table 3.

The gas phase reactions of the trichloromethylium ion with alkyl aromatics, studied by high pressure mass spectrometry

1985 ◽  
Vol 63 (10) ◽  
pp. 2608-2613 ◽  
Author(s):  
John Alfred Stone ◽  
Nancy Joan Moote ◽  
Anastasia C. M. Wojtyniak
Keyword(s):  
Mass Spectrometry ◽  
High Pressure ◽  
Proton Transfer ◽  
Gas Phase ◽  
Rate Constants ◽  
Negative Temperature ◽  
Specific Rate ◽  
Gas Phase Reactions ◽  
Temperature Coefficients ◽  
Primary Products

The reactions of trichloromethylium (CCl3+) with benzene and the lower alkyl aromatics (ArH) have been studied by high pressure mass spectrometry at pressures in the range 2–4 Torr and temperatures from 300 to 560 K. The only two primary products are the adduct ArHCCl3+ and ArCCl2+, which is formed by loss of HCl from the adduct. The relative yields of adduct increase with increasing number of methyl substituents on the aromatic ring (benzene → mesitylene). The disappearance of CCl3+ is kinetically second order with specific rate constants increasing from benzene to mesitylene, the latter reacting essentially at every ion–molecule collision. All rate constants are fairly large (>1010 cc molecule−1 s−1) and show negative temperature coefficients. ArCCl2+ is unreactive but ArHCCl3+ reacts further by proton transfer to ArH.

Sign in / Sign up

Export Citation Format

Share Document