Untitled

Dilger, Herbert; Roduner, Emil; Stolmár, Martina; Reid, I. D.; Fleming, Donald G.; Arseneau, Donald J.; Pan, Jingwen; Senba, M.; Shelley, Mee

doi:10.1023/a:1012633706508

Cited by 17 publications

(14 citation statements)

References 12 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…We treat the chemical transformation Mu → R as occurring at a chemical rate λ ch . The radical MuO 2 so formed undergoes an intrinsic relaxation upon collisions with other molecules, mostly due to spin-rotation and dipolar interactions, and is therefore dependent on the pressure and the applied magnetic field, , whereas Mu is isotropic and does not relax in collisions with an inert moderator. In the presence of oxygen, Mu reacts chemically with the rate λ ch , but it also undergoes spin exchange with the paramagnetic oxygen molecule at a rate λ se .…”

Section: Methodsmentioning

confidence: 99%

Kinetic Isotope Effect in the Gas-Phase Reaction of Muonium with Molecular Oxygen

Himmer¹,

Dilger²,

Roduner³

et al. 1999

J. Phys. Chem. A

View full text Add to dashboard Cite

The rate constant of the gas-phase addition reaction of the light hydrogen isotope muonium to molecular oxygen, Mu + O2 → MuO2, was measured over a range of temperatures from 115 to 463 K at a pressure of 2 bar and from 16 to 301 bar at room temperature, using N2 as the moderator gas. The reaction remains in the termolecular regime over the entire pressure range. At room temperature, the average low-pressure limiting rate constant is k ch 0(Mu) = (8.0 ± 2.1) × 10-33 cm6 s-1, a factor of almost 7 below the corresponding rate constant for the H + O2 addition reaction, k ch 0(H). In contrast to k ch 0(H), which exhibits a clear negative temperature dependence, k ch 0(Mu) is essentially temperature independent. At room temperature, the kinetic isotope effect (KIE) is strongly pressure (density) dependent and is reversed at pressures near 300 bar. The kinetics are analyzed based on the statistical adiabatic channel model of Troe using a Morse potential, which works well in reproducing the overall KIE. The major factors governing the isotope effect are differences in the moment of inertia and density of vibrational states of the addition complex.

show abstract

Section: Methodsmentioning

confidence: 99%

Kinetic Isotope Effect in the Gas-Phase Reaction of Muonium with Molecular Oxygen

Himmer¹,

Dilger²,

Roduner³

et al. 1999

J. Phys. Chem. A

View full text Add to dashboard Cite

show abstract

“…The intercept at 0.3 T (this is the only field that was used for both reactions) is lower by a factor of 4 than for the ethyl radical. This is due to the higher moment of inertia of tert -butyl, which leads to a lower electron relaxation rate. , A list of the chemical rate constants for the reaction is given in Table .…”

Section: Resultsmentioning

confidence: 99%

Kinetics of the Gas-Phase Addition of the Ethyl Radical and the tert-Butyl Radical to NO

Dilger¹,

Stolmár²,

Himmer³

et al. 1998

J. Phys. Chem. A

View full text Add to dashboard Cite

The kinetics of the addition reaction of the ethyl radical and the tert-butyl radical to NO has been investigated at 1.5 bar as a function of temperature (219−475 K) using the muon spin relaxation technique in longitudinal magnetic fields. The data are represented by k 1 = ( ) × 10-10 T -0.5±0.1 cm3 molecule-1 s-1 for the ethyl radical and k 2 = ( ) × 10-4 T -3.1±0.2 cm3 molecule-1 s-1 for the tert-butyl radical, or alternatively by Arrhenius parameters of E a = −(1.4 ± 0.3) kJ mol-1 and A = (1.3 ± 0.2) × 10-11 cm3 molecule-1 s-1 for the ethyl radical and of E a = −(7.3 ± 0.4) kJ mol-1 and A = (5.5 ± 0.9) × 10-13 cm3 molecule-1 s-1 for the tert-butyl radical. They provide a basis for tests of absolute rate theories for reactions occurring on more than one potential energy surface.

show abstract

“…26 The results are given in Table 2 and will be discussed in detail in section 5.3. At a field of 2 T l 0 is very small 49 and because of its independence of the Ni 2+ concentration of no further interest here. However, residual oxygen will have a similar effect as nickel at the same concentration.…”

Section: Information From Spin Exchange Experiments With Ni 2+mentioning

confidence: 95%

Using spin polarised positive muons for studying guest molecule partitioning in soft matter structures

Martyniak

Dilger

Scheuermann

et al. 2006

Phys. Chem. Chem. Phys.

Self Cite

View full text Add to dashboard Cite

Untitled

Cited by 17 publications

References 12 publications

Kinetic Isotope Effect in the Gas-Phase Reaction of Muonium with Molecular Oxygen

Kinetic Isotope Effect in the Gas-Phase Reaction of Muonium with Molecular Oxygen

Kinetics of the Gas-Phase Addition of the Ethyl Radical and the tert-Butyl Radical to NO

Using spin polarised positive muons for studying guest molecule partitioning in soft matter structures

Contact Info

Product

Resources

About