ChemInform Abstract: Photodissociation Dynamics of Acetone at 193 nm: Photofragment Internal and Translational Energy Distributions.

ChemInform ◽  
1990 ◽  
Vol 21 (20) ◽  
Author(s):  
K. A. TRENTELMAN ◽  
S. H. KABLE ◽  
D. B. MOSS ◽  
P. L. HOUSTON
Keyword(s):  
Translational Energy ◽  
Energy Distributions ◽  
193 Nm

scholarly journals Photodissociation Dynamics of the Tert-Butyl Perthiyl Radical

2020 ◽  
Author(s):  
Bethan Nichols ◽  
Erin Sullivan ◽  
Daniel Neumark
Keyword(s):  
Excited State ◽  
Translational Energy ◽  
Energy Distributions ◽  
Dissociation Process ◽  
The Third ◽  
Available Energy ◽  
Three Body ◽  
A Minor ◽  
193 Nm ◽  
State Dissociation

<p>The photodissociation dynamics of the <i>tert</i>-butyl perthiyl (<i>t</i>-BuSS) radical are investigated by fast-beam coincidence translational spectroscopy. A fast (6-8 keV) beam of neutral <i>t</i>-BuSS radicals is produced via photodetachment of the corresponding anion, followed by photodissociation at 248 nm (5.00 eV) or 193 nm (6.42 eV) and coincident detection of the neutral products. Photofragment mass and translational energy distributions are obtained at both wavelengths. At 248 nm, the dominant product channel (90%) is found to be S loss, with a product translational energy distribution that peaks close to the maximum available energy and an anisotropic photofragment angular distribution, indicating dissociation along a repulsive excited state. A minor channel (10%) leading to the formation of S<sub>2</sub> + <i>t</i>-Bu is also observed. At 193 nm, both two- and three-body dissociation are observed. Formation of S<sub>2</sub> + <i>t</i>-Bu is the dominant two-body product channel, with multiple electronic states of the S<sub>2</sub> molecule produced via excited state dissociation processes. Formation of S + <i>t</i>-BuS is a minor two-body channel at this dissociation energy. The three-body channels are S<sub>2</sub> + H + isobutene, S<sub>2</sub> + CH<sub>3</sub> + propene, and S + SH + isobutene. The first two of these channels result from a sequential dissociation process in which loss of S<sub>2</sub> from <i>t</i>-BuSS results in ground state <i>t</i>-Bu with sufficient internal energy to undergo secondary fragmentation. The third three-body channel, S + SH + isobutene, is attributed to loss of internally excited HS<sub>2</sub> from <i>t</i>-BuSS, which then rapidly dissociates to form S + SH in an asynchronous concerted dissociation process. </p>

Photodissociation dynamics of acetone at 193 nm: Photofragment internal and translational energy distributions

1989 ◽  
Vol 91 (12) ◽  
pp. 7498-7513 ◽  
Author(s):  
Karen A. Trentelman ◽  
Scott H. Kable ◽  
David B. Moss ◽  
Paul L. Houston
Keyword(s):  
Translational Energy ◽  
Energy Distributions ◽  
193 Nm

scholarly journals Photodissociation Dynamics of the Tert-Butyl Perthiyl Radical

2020 ◽  
Author(s):  
Bethan Nichols ◽  
Erin Sullivan ◽  
Daniel Neumark
Keyword(s):  
Excited State ◽  
Translational Energy ◽  
Energy Distributions ◽  
Dissociation Process ◽  
The Third ◽  
Available Energy ◽  
Three Body ◽  
A Minor ◽  
193 Nm ◽  
State Dissociation

<p>The photodissociation dynamics of the <i>tert</i>-butyl perthiyl (<i>t</i>-BuSS) radical are investigated by fast-beam coincidence translational spectroscopy. A fast (6-8 keV) beam of neutral <i>t</i>-BuSS radicals is produced via photodetachment of the corresponding anion, followed by photodissociation at 248 nm (5.00 eV) or 193 nm (6.42 eV) and coincident detection of the neutral products. Photofragment mass and translational energy distributions are obtained at both wavelengths. At 248 nm, the dominant product channel (90%) is found to be S loss, with a product translational energy distribution that peaks close to the maximum available energy and an anisotropic photofragment angular distribution, indicating dissociation along a repulsive excited state. A minor channel (10%) leading to the formation of S<sub>2</sub> + <i>t</i>-Bu is also observed. At 193 nm, both two- and three-body dissociation are observed. Formation of S<sub>2</sub> + <i>t</i>-Bu is the dominant two-body product channel, with multiple electronic states of the S<sub>2</sub> molecule produced via excited state dissociation processes. Formation of S + <i>t</i>-BuS is a minor two-body channel at this dissociation energy. The three-body channels are S<sub>2</sub> + H + isobutene, S<sub>2</sub> + CH<sub>3</sub> + propene, and S + SH + isobutene. The first two of these channels result from a sequential dissociation process in which loss of S<sub>2</sub> from <i>t</i>-BuSS results in ground state <i>t</i>-Bu with sufficient internal energy to undergo secondary fragmentation. The third three-body channel, S + SH + isobutene, is attributed to loss of internally excited HS<sub>2</sub> from <i>t</i>-BuSS, which then rapidly dissociates to form S + SH in an asynchronous concerted dissociation process. </p>

Photodissociation of aryl and aryl–alkyl halides at 193 nm: Fragment translational energy distributions

1980 ◽  
Vol 72 (2) ◽  
pp. 1028-1033 ◽  
Author(s):  
A. Freedman ◽  
S. C. Yang ◽  
M. Kawasaki ◽  
R. Bersohn
Keyword(s):  
Alkyl Halides ◽  
Translational Energy ◽  
Energy Distributions ◽  
193 Nm

Scattering of Low-Energy (5-12 eV) C2D4•+ Ions from Room-Temperature Carbon Surfaces

2008 ◽  
Vol 73 (6-7) ◽  
pp. 755-770 ◽  
Author(s):  
Andriy Pysanenko ◽  
Ján Žabka ◽  
Zdeněk Herman
Keyword(s):  
Survival Probability ◽  
Room Temperature ◽  
Incident Angle ◽  
Pyrolytic Graphite ◽  
Carbon Surface ◽  
Translational Energy ◽  
Energy Distributions ◽  
Surface Mass ◽  
Fragment Ions ◽  
Product Ions

The scattering of the hydrocarbon radical cation C2D4•+ from room-temperature carbon (highly oriented pyrolytic graphite, HOPG) surface was investigated at low incident energies of 6-12 eV. Mass spectra, angular and translational energy distributions of product ions were measured. From these data, information on processes at surfaces, absolute ion survival probability, and kinematics of the collision was obtained. The projectile ion showed both inelastic, dissociative and reactive scattering, namely the occurrence of H-atom transfer reaction with hydrocarbons present on the room-temperature carbon surface. The absolute survival probability of the ions for the incident angle of 30° (with respect to the surface) decreased from about 1.0% (16 eV) towards zero at incident energies below 10 eV. Estimation of the effective surface mass involved in the collision process led to m(S)eff of about 57 a.m.u. for inelastic non-dissociative collisions of C2D4•+ and of about 115 a.m.u. for fragment ions (C2D3+, C2D2•+) and ions formed in reactive surface collisions (C2D4H+, C2D2H+, contributions to C2D3+ and C2D2•+). This suggested a rather complex interaction between the projectile ion and the hydrocarbon-covered surface during the collision.

Charge Transfer Between CO22+ and Ar or Ne at Collision Energies 3-10 eV

2003 ◽  
Vol 68 (1) ◽  
pp. 178-188 ◽  
Author(s):  
Libor Mrázek ◽  
Ján Žabka ◽  
Zdeněk Dolejšek ◽  
Zdeněk Herman
Keyword(s):  
Charge Transfer ◽  
Excited States ◽  
Ground State ◽  
Scattering Method ◽  
Translational Energy ◽  
Centre Of Mass ◽  
Energy Distributions ◽  
Zener Model ◽  
Beam Scattering ◽  
Product Ions

The beam scattering method was used to investigate non-dissociative single-electron charge transfer between the molecular dication CO22+ and Ar or Ne at several collision energies between 3-10 eV (centre-of-mass, c.m.). Relative translational energy distributions of the product ions showed that in the reaction with Ar the CO2+ product was mainly formed in reactions of the ground state of the dication, CO22+(X3Σg-), leading to the excited states of the product CO2+(A2Πu) and CO2+(B2Σu+). In the reaction with Ne, the largest probability had the process from the reactant dication excited state CO22+(1Σg+) leading to the product ion ground state CO2+(X2Πg). Less probable were processes between the other excited states of the dication CO22+, (1∆g), (1Σu-), (3∆u), also leading to the product ion ground state CO2+(X2Πg). Using the Landau-Zener model of the reaction window, relative populations of the ground and excited states of the dication CO22+ in the reactant beam were roughly estimated as (X3Σg):(1∆g):(1Σg+):(1Σu-):(3∆u) = 1.0:0.6:0.5:0.25:0.25.

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