Photochemical processes induced by the irradiation of 4-hydroxybenzophenone in different solvents.

摘要: The singlet and triplet excited states of 4-hydroxybenzophenone (4BPOH) undergo deprotonation in the presence water to produce anionic ground-state, causing fluorescence quenching photoactivity inhibition. same process does not take place an aprotic solvent such as acetonitrile. In acetonitrile, 4BPOH is fluorescent (interestingly, one its peaks overlaps with peak C humic substances), it yields oxygen upon irradiation induces triplet-sensitised transformation phenol (with a rate constant (6.6 ± 0.3) × 107 M−1 s−1 (μ σ) between itself 4BPOH). shows intermediate behaviour partially protic 2-propanol, where some observed. acetonitrile/2-propanol mixtures (at least up 50% 2-propanol) there also evidence alcohol oxidation by state, while experimental data are silent concerning possibility pure 2-propanol. Considering that benzophenones important components chromophoric dissolved organic matter (CDOM) surface waters, present findings could have significance for hydrophilic layers vs. hydrophobic cores CDOM.