Rates of 1O2 (1Δg) production upon direct excitation of molecular oxygen by 1270 nm laser radiation in air-saturated alcohols and micellar aqueous dispersions

The oxygenation rates of the O-1(2) trap, 1,3-diphenylisobenzofuran were measured in air-saturated H2O-sodium dodecyl sulfate dispersions, ethanol, methanol and benzene upon direct excitation of dissolved oxygen by infrared (1269 +/- 1 nm) laser radiation. In aqueous dispersions, variation of the detergent concentration from 0.1 to 1 M resulted in the 2.5-time increase of the photooxygenation rate. The absorbance and molar absorption coefficients of oxygen were estimated in all tested systems, water and the micellar phase of detergent dispersions and compared with the rate constants of O-1(2) radiative deactivation obtained from the measurement of the quantum yields of photosensitized O-1(2) phosphorescence. (C) 2008 Elsevier B.V. All rights reserved.