Evidence for long-lived ion-molecule collision complexes from numerical studies

Dugan, J. V.; Rice, James H.P.; Magee, John L.

doi:10.1016/0009-2614(69)80243-5

Cited by 38 publications

(7 citation statements)

References 8 publications

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“…Multiple enCOURters havealso been observed in computer studies of potentially reactive collisions by Polanyi and co-workersl8 and also in ion-dipole collisions by Duggan et aT. 19) before the significance of multiple encounters for any particular system could be judged. 20 Since the mean collision times are increased by multiple encounters, the probability of the occurrence of vibrational transitions is also increased.…”

Section: Multiple Encountersmentioning

confidence: 94%

“…19 One experimental observation which may be due to such complex collisions is the anomalous temperature dependence of the vibrational relaxation times for some polar gases at low temperatures. Multiple enCOURters havealso been observed in computer studies of potentially reactive collisions by Polanyi and co-workersl8 and also in ion-dipole collisions by Duggan et aT.…”

Section: Multiple Encountersmentioning

confidence: 99%

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Classical Collisions of Dipoles and the Transport Properties of Polar Molecules

Clarke¹,

Smith²

1970

The Journal of Chemical Physics

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Articles you may be interested inThe effect of the dipoleinduced dipole potential on ion-polar molecule collision rate constants J. Chem. Phys. 96, 5550 (1992); 10.1063/1.462695Trajectory calculations of the effect of the induced dipole-induced dipole potential on ion-polar molecule collision rate constants Ion-polar molecule collisions. Conservation of angular momentum in the average dipole orientation theory. The AADO theory Classical trajectories for the collisions of dipolar molecules have been calculated for many initial conditions by stepwise integration of the equations of motion. The molecules were represented by hard spheres with point dipoles at their centers and the motion was confined to a plane. Molecular parameters representing, very crudely, the interactions of CHF a , CHaF, and HCl were used and most of the calculations were carried out for relative velocities equal to the mean relative velocity for each gas at 300 o K. The translation-rotation energy exchange and the scattering angle are found to be very sensitive to the initial dipole orientations. The mean scattering angle X and translation-rotation energy exchange JlE, averaged over the two dipole orientations, are shown to be insensitive to the difference of the angular velocities and to be determined mainly by the sum of the angular velocities. Many of the qualitative features of the collisions are found to be predicted by the rough-sphere model. In the second half of the paper the quantitative results are applied to the transport properties of polar gases using the kinetic theory equations of Wang Chang and Uhlenbeck. The effect of energy exchange terms in the viscosity formula is estimated and various methods of calculating transport cross sections for dipolar molecules are compared.

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Section: Multiple Encountersmentioning

confidence: 94%

Section: Multiple Encountersmentioning

confidence: 99%

Classical Collisions of Dipoles and the Transport Properties of Polar Molecules

Clarke¹,

Smith²

1970

The Journal of Chemical Physics

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“…The experiments discussed in this review rely on a scheme elaborated by Dunbar [18] encompassing the properties of an ion trap, as described in Scheme 1. When in the trap, the metal porphyrin ion P + collides with ligand L with frequency k[L], at the top of the centrifugal barrier, ligand L is captured at the distance where the charge attraction overcomes the centrifugal potential [19] ([L] concentration of ligand). Then, a [PL] +* complex is formed that can be stabilized from back dissociation with rate kdiss, either by radiative emission with rate kr, or by collisions with the surrounding gas M (ligand + buffer gas), with rate k[M].…”

Section: Bond Energy Determinationsmentioning

confidence: 99%

“…Relevant kinetic and thermodynamic parameters for NO binding are collected in Table 1 where a comprehensive picture of the kinetics and equilibrium data is presented [19].…”

Section: Five-coordination In No Complexesmentioning

confidence: 99%

Heme ligation in the gas phase

Shafizadeh

Crestoni

Lande

et al. 2021

International Reviews in Physical Chemistry

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“…In the 0^-0 2 and the N^-Ng cases this is about 8 x 1 0-10 cm3 s-1 which is about a hundred times the values inferred from the laboratory data. However, computer studies by Dugan, Rice & Magee (1969) show th a t the frequency characteristic of a single close encounter in which the orbital energy remains positive is 1012 s-1 or higher. At 80 K the ambient gas pres sure would have to be at least some 104 Torr for even one collision with an He atom to be likely during such an encounter.…”

Section: Termolecular Associationmentioning

confidence: 99%

Transition state theory for ion-molecule reactions

1978

Proc. R. Soc. Lond. A

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The standard formula for the rate coefficient given by transition state theory is not valid for exothermic ion-molecule reactions having no activation energy. A formula covering these is derived. For monatomic reactants Langevin’s formula is recovered. In the general case, account must be taken of the long-lived collision complex which arises because of the transfer of orbital energy into the rotational and vibrational modes of the reactants. The theory is applied to bimolecular reactions (most of which it gives to be rapid whether or not an electronic transition is involved), to termolecular association and to radiative association. The major conflict with experiment concerns N 2 + N 2 + + He---- >N 4 + + He which Bohme, Dunkin, Fehsenfeld & Ferguson (1968) have studied at a temperature of 80 K. According to their measurements, the apparent binary rate coefficient is a linear function of the helium pressure, if this is low, but above about a torr it reaches a saturation limit of only around one hundredth of the Langevin rate coefficient, the transition from the linear to the saturation region being quite sharp. Only the initial slope is in agreement with expectation.

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Evidence for long-lived ion-molecule collision complexes from numerical studies

Cited by 38 publications

References 8 publications

Classical Collisions of Dipoles and the Transport Properties of Polar Molecules

Classical Collisions of Dipoles and the Transport Properties of Polar Molecules

Heme ligation in the gas phase

Transition state theory for ion-molecule reactions

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