Collection of Czechoslovak Chemical Communications - digital archive 

Abstract

In the micellar medium of sodium dodecyl sulphate the monomer-dimer equilibrium of methylene blue is shifted markedly in favour of the monomer. Methylene blue quenches the fluorescence of pyrene solvated in micelles, which is explained in terms of resonance energy transfer. Based on the theoretical model, the pyrene fluorescence quenching constant in the micelles was determined (k_qm = 1.8 10⁶ s^-1) and the average pyrene-methylene blue interaction distance for the singlet-singlet energy transfer estimated. The T₁ → T_n absorption of methylene blue is quenched by pyrene and tetrasodium salt of ethylenediaminetetraacetic acid (EDTA); the quenching rate constants corresponding to the electron transfer are 5 10⁶ and 2.05 10⁸ 1 mol^-1 s^-1, respectively.