Photodissociation spectroscopy of MgCH3I+: dissociation processes via charge transfer and/or chemical bond rupture

Photodissociation spectrum of MgCH3I+ is measured by using a reflectron time-of-flight mass spectrometer and a tunable UV laser. There are three bands peaking at about 27 200, 29 600, and 38 100 cm−1, which all originate from 2P ← 2S transition of Mg+. In the dissociation processes, five kinds of ions, CH3+, Mg+, I+, CH3I+, and MgI+, are observed as fragments. Photodissociation spectrum is assigned by theoretical calculations, and dissociation processes are discussed from the consideration of potential energy curves including charge transfer states along the Mg–I bond distance obtained by CIS calculation.