The hunt for HCO(aq)

Abstract

In contrast to its strong presence in gas-phase reactions, the formyl radical, HCO, has never been identified in aqueous solution. Here the photolysis of aqueous formate anions, HCOO⁻(aq), following the excitation of the (nπ*) transition at 200 nm is studied by infrared femtosecond transient absorption spectroscopy with the purpose of identifying the aqueous formyl radical photoproduct, HCO(aq). However, HCO(aq) is not observed. The experiments indicate that HCO(aq) exists for less than one picosecond before it reacts with the surrounding water molecules.