Intermolecular hydrogen atom abstraction from the fluoranil triplet excited state: a Raman study

Intermolecular hydrogen abstraction reaction mechanisms in photoexcited ketones have traditionally been studied using time resolved absorption spectroscopy. Another approach is presented involving time resolved resonance Raman spectroscopy to study such reactions, using the fluoranil/isopropanol system as an example. It has been shown that vibrational spectra can be recorded starting from the triplet excited state to the product state (radical anion) via the intermediate state, which is the ketyl radical. Thus, it is demonstrated that following the reaction evolution in terms of structural (vibrational modes) details would prove to be useful not only for mechanistic investigation but also for structure-reactivity correlations in photoexcited systems.