Vibrational and electronic spectra of (CH3OH)3 (n = 1–3) measured by infrared photodissociation spectroscopy

Photodissociation spectra of Co n + (CH3OH)3 (n = 1–3) were measured in the region of 2800–6800 cm−1. A broad near-infrared (-IR) absorption was observed in the spectra of n = 2 and 3, in addition to the vibrational absorption in the mid-IR region. With the aid of a calculation based on time-dependent density functional theory (TD-DFT), the near-IR absorption is assigned to the electronic transitions between the levels located near the highest occupied and the lowest unoccupied levels of Co n + (CH3OH)3, in which one or two methanol molecules dissociate to CH3 and OH fragments and the fragments adsorb on the bridge sites of Co n + .