Solvent-enabled photodissociation of CO2- in water clusters

The photodissociation of hydrated CO2- is observed in 355 nm photofragmentation of the CO2-(H2O)m, m = 3-20 cluster anions. The intra-cluster CO2-→O-+CO reaction is proposed to proceed by a Renner-Teller mediated mechanism via a hydration-stabilized excited state originating from a low-lying CO2- resonance.