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-O-2 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(P-2(312)) atoms indicates photogeneration of precursor CH3I molecules via complex-specific channel with excitation energy expected for double spin-flip transition in complex CH3I-O-2. The angular distribution for recoil directions of I(P-2(3/2)) atoms coming from vdW complexes also corresponds to that expected for double spin-flip transition. (C) 2016 Elsevier B.V. All rights reserved.