Water-soluble porphyrins having fluorine groups as a highly sensitive chromogenic reagent for lead(II) ion

Abstract

New water-soluble porphyrins having fluorine groups [i.e., 5,10,15,20-tetrakis(2-fluorosulfophenyl)porphine, 5,10,15,20-tetrakis(2,6-difluorosulfophenyl)porphine and 5,10,15,20-tetrakis(2,3,5,6,-tetrafluorosulfophenyl)porphine (TF₄SP)] have been synthesised and characterized. Moreover, the spectrophotometric determination of 10^–7 mol dm^–3 levels of lead(II) ion using TF₄SP has been demonstrated (ε_Pb–TF4SP= 20 × 10⁴ mol^–1 dm³ cm^–1; reaction time, 2 min at 25 °C; and pH =9).