Ultrafast Dissociation Dynamics of Iodomethane Induced by Few-Fs UV Pulses

Ultraviolet (UV) radiation plays a pivotal role in initiating photochemical and photobiological processes. However, capturing the initial stages of molecular dynamics that occur immediately after UV light absorption presents a significant challenge. This difficulty arises from the limited availability of UV-pumped time-resolved setups that can achieve the necessary few-femtosecond resolution. [1]. In this work, we present the first combined experimental and theoretical study of the ultrafast dissociation dynamics of the benchmark molecule iodomethane (CH3I) performed with few-fs UV pulses. In CH3I, a single UV-photon transition leads to a rapid cleavage of the C-I bond [2]. Furthermore, the presence of a conical intersection (CI) near the Franck-Condon (FC) region makes iodomethane a popular test case for investigating the effects of UV-induced non-adiabatic crossings at ultrafast timescales.