Complexation of Iron by Dopamine Analogs; A Spectrophotometric and Potentiometric Study

The chelation of Bio-essential metal, Iron, with dopamine analogs was studied at 30±2°C. Fe²⁺ formed intense color complex with these molecules with an absorbance maxima in visible region. A distinct peak of Fe-Carbidopa complex at 364nm with molar absorptivity of 1600 M^-1 cm^-1 was observed while that of Fe-Levodopa and Fe-Methyldopa were observed at 730nm with molar absorptivities of 306 M^-1 cm^-1 and 2300 M^-1 cm^-1 , respectively. Potentiometric studies of the complex indicate that Fe(II) forms a 1:3 complex with levodopa and methyldopa while a 1:2 complex is found in case of carbidopa. The results obtained are consistent with the spectrophotometric studies.