Vacuum ultraviolet photolysis of hydrogen sulphide

Tunneling Reaction Kinetics for the Hydrogen Abstraction Reaction H + H2S → H2 + HS in the Interstellar Medium

“…The crossover temperature is 286 K. Corresponding bimolecular rate constants are depicted in Figure . The high-temperature rate constants coincide with previous experimental and theoretical work. − With a value of 1.8 × 10 –10 cm 3 molecule –1 s –1 , we are in close agreement with the experimental values of ∼1.5 × 10 –10 cm 3 molecule –1 s –1 at 2000 K, and likewise, our value of 2.3 × 10 –13 cm 3 molecule –1 s –1 is close to the experimental value of ∼2 × 10 –13 cm 3 molecule –1 s –1 at 200 K. Note that these rate constants are calculated using σ = 2. The precise values are listed in the Supporting Information.…”

“…2. The high-temperature rate constants coincide with previous experimental and theoretical work [22][23][24][25][26][27][28][29][30][31][32][33][34][35][36] . With a value Note that these rate constants are calculated using σ = 2.…”

“…. The high-temperature rate constants coincide with previous experimental and theoretical work[22][23][24][25][26][27][28][29][30][31][32][33][34][35][36] . With a value of 1.8×10 −10 cm −3 molecule −1 s −1 we are in close agreement with the experimental values of ∼1.5×10 −10 cm −3 molecule −1 s −1 at 2000 K, and likewise our value of 2.3×10 −13 cm −3 The precise values are listed in the Supporting Information.…”

“…Although an exchange reaction is in principle also possible, it was found that the abstraction channel is favored. Within the framework of combustion chemistry, the importance and non-Arrhenius behavior of reaction has been realized, and gas-phase rate constants have been both measured and calculated in the temperature range of 200–2560 K. ,− Non-Arrhenius behavior is a sign of the importance of tunneling for the reaction. The barrier (∼12.7 kJ/mol) is indeed quite high to be overcome thermally as the temperature decreases.…”

Mode- and Bond-Selected Reaction of H with Local Mode Molecule HDS

“…There exist two reaction channels: the abstraction channel to products H 2 and SH and the exchange channel to H 2 S and H. The two channels have similar barrier heights (3.72 kcal mol –1 vs 5.51 kcal mol –1 ), and thus the competition between them is expected . The kinetics of the hydrogen abstraction channel has been studied by various kinds of experimental techniques, in which a non-Arrhenius temperature dependence of thermal rate constants was identified. − Theoretical calculations attributed the observed non-Arrhenius behavior to the quantum tunneling effect. − …”