Solvation dynamics elementary reactions in solvent cages

Solvation Dynamics Elementary Reactions in Solvent Cages 

For chemical reactions in solution, the solvent plays an important role in the elementary processes of bond making and breaking. For example, it may enhance bond formation by trapping reactive species in a solvent cage on the time-scale of the reaction it also may act as a chaperone that stabilizes energetic species. One of the most studied reactions in the condensed phase is that of dissociation of neutral iodine molecules most recently, it has been studied using ultrafast lasers to investigate its femtosecond dynamics. 

Clusters of neutral iodine molecules, I2, in argon can be produced in a molecular beam. The average size of the clusters formed can be adjusted in the range of 40 to 150 argon atoms, as a function of backing pressure, at an average temperature of 30 K or less. The real time dynamics of cluster dissociation has been studied by Zewail and coworkers (Zewail, 1995). The dissociation of the I2 within the cluster is induced by a femtosecond laser pulse, which prepares a wave packet, either 

The presence of the argon cluster gives rise to a solvent cage, and as a result a solvent barrier to dissociation is generated by the repulsion between iodine and argon atoms. 

Laser Chemistry Spectroscopy, Dynamics and Applications Helmut H. Telle, Angel Gonzalez Urena i 2007 John Wiley Sons, Ltd ISBN 978-0-471-48570-4 (HB) ISBN 978-0-471-48571-1 (PB) 

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