Nitrosyl iron(II) complexes of porphyrins substituted with highly electron-withdrawing CF 3 groups: Electronic absorption, MCD and EPR spectral study

Abstract

Five- and six-coordinated nitrosyl iron(II) complexes of etioporphyrin I and electron-deficient porphyrins with one, two or four CF 3 groups at pyrrole β-positions of a porphyrin have been prepared and the electronic absorption, MCD, IR and EPR spectra of their complexes have been measured at room temperature and 77 K. Both the line shape and parameters varied with the number of CF 3 substituents with a highly electron-withdrawing ability. Their data were evaluated by using the first redox potentials of free base porphyrin as a measure of the electron-withdrawing or -donating ability of the porphyrin peripheral substituents.