Disposal of reactant vibrational excitation in adiabatically endothermic reactions. I. H+D{sub 2}({ital v}{double_prime}=1, {ital j}{double_prime}=2){r_arrow}HD({ital v}{prime}, {ital j}{prime})+D
- Department of Chemistry, Columbia University, New York, New York 10027 (United States)
We report absolute partial and total cross sections for the H+D{sub 2}({ital v}{double_prime}=1, {ital j}{double_prime}=2){r_arrow}HD({ital v}{prime}, {ital j}{prime})+D reaction at {ital E}{sub rel}=1.3 eV. Addition of D{sub 2} reactant vibrational energy increases the total reactive cross section from 1.2 to 2.5 A{sup 2}. That a similar amount of increased collision energy does not increase the cross section to such an extent distinguishes reactant vibrational energy from reactant translational energy. The average rotational energy for the HD product increases from 0.25 to 0.44 eV, but the effect is caused entirely by increased rotational energy in the {ital v}{prime}=0 vibrational ground state. Reactant vibrational energy does not enhance the rotational energy for {ital v}{prime}=1 and only modestly enhances HD vibrational energy. The average vibrational energy {l_angle}{ital E}{sub {ital v}}{r_angle} is 0.10 eV for the {ital v}{double_prime}=0 reaction and 0.16 eV for the {ital v}{double_prime}=1 reaction. These results contrast with those of the D+H{sub 2}({ital v}{double_prime}={ital j}{double_prime}=1){r_arrow}HD({ital v}{prime},{ital j}{prime})+H reaction at {similar_to}1.4 eV, in which the vibrational energy of the HD product is three times as great for the {ital v}{double_prime}=1 reaction as for the {ital v}{double_prime}=0 reaction. This difference in reactions may be explained by the reactant H{sub 2} vibrational energy, as opposed to the reactant D{sub 2} vibrational energy, exceeding one quantum of vibration of the product HD. There is no specific or selective channeling of reactant vibration into product rotation in the present case, but reactive trajectories that allow channeling into {ital v}{prime}=0, high {ital j}{prime} quantum states are enhanced upon the addition of D{sub 2} vibrational energy. {copyright} {ital 1995} {ital American} {ital Institute} {ital of} {ital Physics}.
- OSTI ID:
- 69051
- Journal Information:
- Journal of Chemical Physics, Journal Name: Journal of Chemical Physics Journal Issue: 2 Vol. 103; ISSN JCPSA6; ISSN 0021-9606
- Country of Publication:
- United States
- Language:
- English
Similar Records
State-to-state dynamics of atom+polyatom reactions. III. The H+CDCl[sub 3][r arrow]HD([ital v][prime],[ital j][prime])+CCl[sub 3] reaction
State-to-state dynamics of atom + polyatom abstraction reactions. I. The H+CD sub 4 r arrow HD( v prime , J prime )+CD sub 3 reaction