The carbonate, Co3-• solution studied by resonance Raman spectroscopy

The carbonate radical (CO3-.) is of biological significance acting as an intermediate in free radical-mediated damage and is capable of oxidising amino acids and proteins. In order to distinguish between the four possible structures of CO3-., nanosecond time-resolved resonance Raman (TR3) experiments were undertaken. Photolysis of persulphate at 250 nm generated the SO4-. radical which then oxidised sodium carbonate. Resonance Raman spectra of the resulting CO3-. radical were obtained using a probe wavelength of 620 nm. Point group theory calculations and interpretation of the TR3 spectra suggest that the radical has C-2 upsilon molecular symmetry.