Eur. Phys. J. D (2013) 67: 265
https://doi.org/10.1140/epjd/e2013-40366-0

Regular Article

Wave packet study of the methyl iodide photodissociation dynamics in the 266−333 nm wavelength range

¹ Departamento de Física Atómica, Molecular y de AgregadosInstituto de Física Fundamental, Consejo Superior de Investigaciones Científicas, Serrano 123, 28006 Madrid, Spain
² Departamento de Química Física I, Facultad de Ciencias Químicas, and Unidad Asociada de I+D+i al Consejo Superior de Investigaciones Científicas, Universidad Complutense de Madrid, 28040 Madrid, Spain

^a e-mail: garciavela@iff.csic.es

Received: 18 June 2013
Received in final form: 24 September 2013
Published online: 17 December 2013

Abstract

Photolysis of CH₃I is studied in the range of excitation wavelengths λ = 266−333 nm using a three-dimensional wave packet method. The aim is to try to clarify some discrepancies arisen in different experiments for the vibrational distributions of the CH₃   (ν₂) fragment (being ν₂ the umbrella bend mode or the symmetric deformation mode of the CH₃ group) produced through the channel CH₃   (ν₂) + I(²P_3/2). The simulations predict non-statistical vibrational distributions peaking at ν₂ = 1 in the range λ = 266−315 nm, and a change to statistical behavior with a maximum at ν₂ = 0 for longer wavelengths. The calculations agree qualitatively with all the available experiments for λ = 266−280 nm. For λ ≥ 298 nm theory is consistent with one of the experiments and disagrees with the other two.