Infrared spectroscopy of CO₃^•−(H₂O)_1,2 and CO₄^•−(H₂O)_1,2

Hydrated molecular anions are present in the atmosphere. Revealing structure of microsolvation is key to understanding their chemical properties. The infrared spectra CO3•−(H2O)1,2 and CO4•−(H2O)1,2 were measured via multiple photon dissociation spectroscopy both warm cold environments. Redshifted from free O–H stretch frequency, broad, structured observed stretching region for all cluster ions, which provide information on interaction hydrogen atoms with central ion. In C–O region, exhibit clear maxima, but was surprisingly inefficient. While CO4•−(H2O) dissociate loss water, CO2 dominant channel CO4•−(H2O)2. experimental compared calculated within harmonic approximation analysis dynamics simulations. simulations support hypothesis that many isomers contribute spectrum at finite temperatures. highly fluxional nature clusters main reason spectral broadening, while water–water bonding seems play a minor role doubly hydrated species.