A Monte Carlo study of energy transfer in thermal unimolecular reactions: an application to diatomic dissociation

Stace, A. J.

doi:10.1080/00268977900101581

Cited by 14 publications

(1 citation statement)

References 29 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…In addition, rotational excitation is also considered in this work because rotational energy content of a diatomic ion can alter significantly the vibrational dissociation barrier and thereby affect calculated dissociation rates. Our approach differs from other simulations of diatomic dissociation 26,27 in that it provides estimates of ion internal temperatures for a prototypical strongly bound diatomic ion, complementing a recently reported work which has correlated ion activation conditions and effective ion internal temperatures for a relatively large polyatomic ion, protonated leucine enkephalin. 28 The results reported herein are highly relevant to understanding the chemical and physical phenomena underlying the use of the ion trap as a tool in elemental mass spectrometry, [29][30][31][32][33][34][35] wherein the destruction of polyatomic ion interferences is often desirable.…”

Section: Introductionmentioning

confidence: 94%

Collision-Induced Dissociation in Quadrupole Ion Traps: Application of a Thermal Model to Diatomic Ions

2001

View full text Add to dashboard Cite

Dissociation of the tantalum oxide cation, a strongly bound diatomic, is simulated for the multiple-collision environment of a quadrupole ion trap mass spectrometer using a model based on thermal unimolecular reaction theory. The intact diatomic ion is assigned a specific internal temperature at which it undergoes collisional activation and deactivation during a random walk in energy space. Collisional energy transfer is assumed to proceed via independent vibrational and rotational processes, as described by the refined impulse approximation and exponential transition probability, with dissociation occurring when the vibrational energy exceeds the rotational-energy-dependent barrier for dissociation. Processing the data from many such random walks yields the simulated dissociation kinetics and time-dependent internal energy distribution of an ion population at the specified internal temperature. Comparison of experimental dissociation rates with those obtained via simulations performed over a series of temperatures enables prediction of internal temperatures and corresponding internal energy distributions for tantalum oxide ion populations undergoing resonance excitation. Although the simulations indicate that rotational-energy transfer can lead to significantly higher dissociation rates than those associated with purely vibrational-energy transfer, the results obtained in this study suggest that ion internal temperatures in the tens of thousands of degrees are required nonetheless to dissociate a strongly bound diatomic ion such as tantalum oxide, and the experimental data demonstrate that resonance excitation in a quadrupole ion trap can achieve the necessary temperatures.

show abstract

Section: Introductionmentioning

confidence: 94%

Collision-Induced Dissociation in Quadrupole Ion Traps: Application of a Thermal Model to Diatomic Ions

2001

View full text Add to dashboard Cite

show abstract

Analytical solution of vibrational–rotational energy transfer in the dissociation and relaxation of N₂, Br₂, and CO at high temperature

Forst

1981

Int J of Chemical Kinetics

View full text Add to dashboard Cite

An approximate analytical solution of relaxation in a low-pressure system with exponential transition probabilities is given for vibrational-rotational energy transfer in the dissociation of diatomics. The main assumption is that the rotational degrees of freedom are in thermal equilibrium at all times, and that the harrier to dissociation in the vibrational-rotational plane is linear and asymmetric. The theory is applied to high-temperature dissociations of Nz, Brz, and CO in excess argon, with satisfactory agreement with available experimental data.

show abstract

The role of electronically excited states in recombination reactions

Smith¹

1984

Int J of Chemical Kinetics

102

View full text Add to dashboard Cite

Methods are described for including the participation of bound electronically excited states in calculations on radical recombination reactions. These methods are illustrated by applying them to the reactionsFor O,, accurate a b initio potentials are used in calculations which show that the electronic degeneracy and long-range part of the potential are likely to be crucial in determining the contribution of a given electronic state to the overall reaction, as long as the state is not so weakly bound that it dissociates thermally before being electronically quenched. Weak collision effects are allowed for using a Monte Carlo technique and an assumed exponential form for the distribution of energies transferred in collisions with a third body. For larger systems it is evident that the role of bound excited states in the low-pressure regime falls rapidly as the size of the system increases. As the high-pressure limit is approached, however, the contribution of excited states is likely to come close to that expected simply on the basis of electronic degeneracy.

show abstract

A Monte Carlo study of energy transfer in thermal unimolecular reactions: an application to diatomic dissociation

Cited by 14 publications

References 29 publications

Collision-Induced Dissociation in Quadrupole Ion Traps: Application of a Thermal Model to Diatomic Ions

Collision-Induced Dissociation in Quadrupole Ion Traps: Application of a Thermal Model to Diatomic Ions

Analytical solution of vibrational–rotational energy transfer in the dissociation and relaxation of N₂, Br₂, and CO at high temperature

The role of electronically excited states in recombination reactions

Contact Info

Product

Resources

About

A Monte Carlo study of energy transfer in thermal unimolecular reactions: an application to diatomic dissociation

Cited by 14 publications

References 29 publications

Collision-Induced Dissociation in Quadrupole Ion Traps: Application of a Thermal Model to Diatomic Ions

Collision-Induced Dissociation in Quadrupole Ion Traps: Application of a Thermal Model to Diatomic Ions

Analytical solution of vibrational–rotational energy transfer in the dissociation and relaxation of N2, Br2, and CO at high temperature

The role of electronically excited states in recombination reactions

Contact Info

Product

Resources

About

Analytical solution of vibrational–rotational energy transfer in the dissociation and relaxation of N₂, Br₂, and CO at high temperature