Hd. Duong et al., HETEROGENEOUS ELECTRON-TRANSFER REACTIONS AT LIQUID LIQUID INTERFACESSTUDIED BY TIME-RESOLVED ABSORPTION-SPECTROSCOPY/, Journal of photochemistry and photobiology. A, Chemistry, 117(1), 1998, pp. 27-33
The triplet excited state of water-soluble porphyrin has been found to
be quenched by tetracyanoquinodimethane both in homogeneous solutions
, in a water/acetonitrile mixture, and at the liquid/liquid interface
between water and toluene. Time-resolved transient absorption spectros
copy in total internal reflection excitation mode (in the liquid/liqui
d interface case) is used to monitor the decay of the excited porphyri
n triplet state. In homogeneous solutions, the quenching is efficient
and diffusion controlled. Photoproducts are obtained with a high yield
only with negatively charged porphyrins. In the case of heterogeneous
electron transfer, kinetics data are obtained from the analysis of th
e relevant mass transfer regime. (C) 1998 Elsevier Science S.A. All ri
ghts reserved.