Oxygen-assisted excitation of methyl iodide as a test of double spin-flip transition in van der Waals complex CH3I-O2

Photoexcitation of van der Waals (vdW) complex CH3I-O2 has been studied with velocity map imaging of I atoms arising in photodissociation. A new scheme of resonance-enhanced multiphoton ionization of iodine atoms has been applied with simultaneous use of UV and VIS radiation. The measured kinetic energy of I(2P3/2) atoms indicates photogeneration of precursor CH3I molecules via complex-specific channel with excitation energy expected for double spin-flip transition in complex CH3I-O2. The angular distribution for recoil directions of I(2P3/2) atoms coming from vdW complexes also corresponds to that expected for double spin-flip transition.

Alexandr S. Bogomolov and Sergei A. Kochubei and Alexey V. Baklanov

Chemical Physics Letters 2016, 661