Search

Abstract: The oxygenation rates of the 1O2 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±1nm) laser radiation. In aqueous dispersions, variation of the detergent concentration from 0.1 to 1M 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 1O2 radiative deactivation obtained from the measurement of the quantum yields of photosensitized 1O2 phosphorescence. [Copyright &y& Elsevier]

Abstract: The rates of oxygenation of the 1O2 trap, 1,3-diphenylisobenzofuran were measured in air-saturated organic solvents and heterogeneous D2O-sodium dodecyl sulfate dispersions upon infrared (1267±4nm) laser irradiation. The absorbance and molar absorption coefficients of oxygen corresponding to this wavelength were estimated from the observed oxygenation rates. The data suggest that 1O2 was formed due to direct oxygen excitation without appreciable involvement of vibrationally excited solvent molecules. The minor ‘pseudophase’ of detergent micelles was shown to strongly enhance overall 1O2 production in D2O-detergent dispersions. [Copyright &y& Elsevier]