Measurements of the bimolecular rate constants for S + O2 ? SO + O and CS2 + O2 ? CS + SO2 at high temperatures

1986 ◽  
Vol 18 (8) ◽  
pp. 871-884 ◽  
Author(s):  
Ko Saito ◽  
Yuji Ueda ◽  
Reiko Ito ◽  
Terumitsu Kakumoto ◽  
Akira Imamura
Keyword(s):  
High Temperatures ◽  
Rate Constants

Anharmonic effect of the unimolecular dissociation of Glycerol to Glycidol

2018 ◽  
Vol 17 (06) ◽  
pp. 1850040
Author(s):  
Qian Li ◽  
Li Yao ◽  
S. H. Lin
Keyword(s):  
Growth Rate ◽  
Comparative Analysis ◽  
High Temperatures ◽  
Rate Constants ◽  
Canonical System ◽  
Dissociation Rate ◽  
Unimolecular Dissociation ◽  
Anharmonic Effect ◽  
Total Energies ◽  
Dissociation Rate Constants

The unimolecular dissociation rate constants of the dehydration of Glycerol to Glycidol were calculated at the MP2/6–311G(d,p) level using the Rice–Ramsperger–Kassel–Marcus (RRKM) theory. The anharmonic effect of the reactions was examined by comparing the rate constants at temperatures (700–3000[Formula: see text]K) of the canonical case and total energies (25654–53089[Formula: see text]cm[Formula: see text]) of the microcanonical system. The calculations showed that high temperatures are required for the reaction to proceed. As the temperatures and total energies increased, the rate of reactions increased. However, the growth rate of the unimolecular dissociation rate constants was high and slower both in the canonical and microcanonical systems. Comparative analysis showed that the anharmonic effect was most significant for the reaction [Formula: see text] and least significant for the reaction [Formula: see text]. The anharmonic effect became more significant as the temperatures and total energies increased. Compared with the microcanonical situation, the anharmonic effect of the canonical system was more pronounced.

Estimation of rate constants for near-diffusion-controlled reactions in water at high temperatures

1990 ◽  
Vol 86 (9) ◽  
pp. 1539 ◽  
Author(s):  
A. John Elliot ◽  
David R. McCracken ◽  
George V. Buxton ◽  
Nicholas D. Wood
Keyword(s):  
High Temperatures ◽  
Rate Constants ◽  
Diffusion Controlled

Rate constants for the energy-pooling and -quenching reactions of singlet molecular oxygen at high temperatures

1982 ◽  
Vol 86 (5) ◽  
pp. 700-703 ◽  
Author(s):  
Patricia M. Borrell ◽  
Peter Borrell ◽  
Kevin R. Grant ◽  
Michael D. Pedley
Keyword(s):  
Molecular Oxygen ◽  
High Temperatures ◽  
Rate Constants ◽  
Singlet Molecular Oxygen ◽  
Energy Pooling

High temperature studies of singlet excited oxygen, O 2 ( 1 Σ g + ) and O 2 ( 1 Δ g ), with a combined discharge flow/shock tube method

1979 ◽  
Vol 367 (1730) ◽  
pp. 395-410 ◽  
Keyword(s):  
Steady State ◽  
Shock Tube ◽  
Excited States ◽  
High Temperatures ◽  
Rate Constants ◽  
Microwave Discharge ◽  
Discharge Flow ◽  
Direct Collision ◽  
State Concentration ◽  
Excited Oxygen

The excited states of oxygen, O 2 ( 1 Δ g ) and O 2 ( 1 Σ g + ), generated in a microwave discharge, were shock heated in order to study their reactions at temperatures in the range 650-1650 K. The increase in the dimol emission (634 nm) from O 2 ( 1 Δ g ) behind the shock front is consistent with the simple collisional model for the production of the emission; the rate of quenching of O 2 ( 1 Δ g ) by O 2 is too slow to measure at high temperatures with the technique. The emission from O 2 ( 1 Σ g + ) increases because of the shock compression and then is further enhanced by a displacement in the steady state concentration which is maintained by the two reactions pooling: 2O 2 ( 1 Δ g )->O 2 ( 1 Σ g + )+O 2 ( 3 Σ g - ) k p ; quenching: O 2 ( 1 Σ g + )+M->O 2 ( 3 Σ g - or 1 Δ g )+M; k q M . The relaxation to the enhanced level of emission permits k M q to be measured directly and then k p is calculated from the enhanced steady state emission level and k M q . There is no evidence for direct, collision induced! enhancement of the emission from O 2 ( 1 Σ g + ). Curved Arrhenius plots of the rate constants were found; some values are given in table 2. The results appear to indicate that in each case there are two mechanisms operating; one involving short range forces, and the other, long range forces or a collision complex. An evaluation is given of the discharge flow-shock tube technique as a method for determining rate constants at high temperatures.

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