Photodissociation dynamics of trimethyltin iodide

The photodissociation dynamics of (CH3)3SnI has been investigated in the semi-classical approximation and in the quasi-resonant approximation by URIMIR (Unimolecular Reactions Induced by Multiphoton or Infra-Red Radiation), as well as by direct numerical integration of the time dependent Schrödinger equation with a one-dimensional model describing the Sn-I bond elongation. Potential energy functions (PEF) and associated dipole moment functions (DMF) result from non-linear fits of the MS-CASPT2 (Multi-State Complete Active Space 2nd Order Perturbation Theory) potential energies and dipole transition moments including spin-orbit effects. Preliminary simulations of the excited states dynamics suggest that the ionic channel should be populated by irradiation at about 207 nm. The branching ratio for the formation of ionic products ((CH3)3Sn+ + I−) to that of radical products ((CH3)3Sn + I) could be higher than 5:1 for pulse lengths on the order of 150-200 fs at 50 TW cm−2.