Intramolecular Photo-Oxidation as a Potential Source to Probe Biological Electron Damage: A Carboxylated Adenosine Analogue as Case Study

A carboxylated adenosine analog (C-Ado−) has been synthesized and probed via time-resolved photoelectron spectroscopy in order to induce intra-molecular charge transfer from the carboxylic acid moiety nucleobase. Intra-molecular can be exploited as starting point probe low-energy electron (LEE) damage DNA its derivatives. Time-dependent density functional theory (TD-DFT) calculations at B3LYP-6311G level of have performed verify that highest occupied molecular orbital (HOMO) was located on lowest (LUMO) Hence, could work source, whilst nucleobase serve purpose acceptor. The dynamics following excitation 4.66 eV (266 nm) were using probes 1.55 (800 3.10 (400 nm). data show rapid decay excited state population and, based similarity overall deoxy-adenosine monophosphate (dAMP–), it appears dominant mechanism is internal conversion 1ππ* nucleobase, rather than charge-transfer