| Abstract: | Summary. The fluorescence quenching and complexation behaviour of tetraphenylporphyrin (TPP) with some organic acceptors such as chloranilic acid (CHL), 5,5 -dithiobis-2-nitrobenzoic acid (DTNB), or 3,4-dinitrobenzoic acid (DNB) and tetravalent metal ions such as Th4+ and Zr4+ have been studied in methanol. The second-order fluorescence quenching rate constant (kq), the association constant (K), the molar absorption coefficient ( ), and the thermodynamic parameters of the complexation process ( G°, H°, and S°) have been evaluated using different organic solvents. |
