Photoinduced removal of molecular oxygen from solutions.

We propose a new, simple and efficient procedure of light-driven deoxygenation of solutions based on hydroperoxides formation upon irradiation. Efficient and fast removal of molecular oxygen is caused by photosensitized generation of singlet oxygen, which then reacts with the solvent (2-methyltetrahydrofuran or tetrahydrofuran). Oxygen depletion makes it possible to observe processes normally undetectable in non-degassed liquid samples at room temperature, such as phosphorescence and triplet-triplet annihilation. The potential of the proposed protocol is demonstrated by recording of previously unknown phosphorescence of palladium complex of octaethylporphycene.