Product kinetic energy release distributions

Organometallic Reaction Energetics from Product Kinetic Energy Release Distributions... 

General Considerations. Statistical product kinetic energy release distributions can be used to determin as phase bond dissociation energies for organometallic species. Tne amount of energy appearing as product translation can be used to infer details of the potential ener surfaces primarily in the region of the exit channel and has implications for the ease with which the reverse association may occur. 

Figures, t othetical potential energy surfaces for the reaction M+ + A + C and the corresponding product kinetic energy release distributions in the center-oi-mass fiame.

Practical Considerations in Calculations. In order to calculate kinetic energy release distributions, structures and vibrational frequencies for the various species are required. These are taken from the literature where possible, or estimated from literature values of similar species. The details of the kinetic energy release distributions are found to va only weakly with structure or vibrational frequencies over the entire physically reasonable range for these quantities. The distributions are strongly dependent on the total energy available to the dissociating complex, and hence in our model to the AH of reaction. Often all heats of formation of product and reactants are well known except one, the organometallic product ion. This quantity can then be used as a parameter and varied until the best fit with experiment is obtained. 

KERD Kinetic energy release distribution— the probability distribution for observing product fragments in a dissociative process with a particular value of the relative kinetic energy. 

Kinetic energy release distributions Ion intensities vs. product kinetic energy 1992BEA... 

Figure 3 The PEPICO TOF distribution of C2H5 ions from energy selected C2H5l + ions at various energies above the dissociation limit for - loss. The solid lines that fit the experimental points are single energy release distributions. From these data, the whole distribution of product translational energies could be determined. Reproduced with permission from Baer T, Buchler U and Klots TCE (1980) Kinetic energy release distributions for the dissociation of internal energy selected C2H5l + ions. Journal de Chimie Physique 77 739-743.

In a unimolecular dissociation, excess product energy is typically distributed among the translational, rotational and vibrational modes in a statistical fashion. The experimentally observed phenomenon is the distribution of translational kinetic energies of the departing fragment ions (the kinetic energy release, KER)... 

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