Oxygen activation in aerated solvents by red and infrared laser radiation: measurement of the absorption spectra of dissolved oxygen molecules

Oxygen activation was studied in aerated organic solvents under laser irradiation in the wavelength range 600-1300 nm using chemical trapping and phosphorescence of singlet oxygen. In the interval 740-1300 nm, only two excitation peaks at 765 and 1273 nm were observed, which apparently belong to the absorption bands of monomeric oxygen molecules. Under excitation at shorter wavelengths, the activities of the vibrational oxygen band at 690 nm and complexes of oxygen with solvents and traps were revealed. No photosensitizing activity of oxygen dimols was detected. The obtained absorption spectra of dissolved oxygen are discussed.