Correlation Between the Rate of Intramolecular Electron Transfer of Dinuclear Iron Complexes(?,III) and the Phases of the Molecular Structures

Abstract

Dinuclear iron(II, III) complexes with a hexadentate ligand [Fe₂bpmp(L)₂](BF₄)₂ were prepared, where Hbpmp represents 2,6-bis[bis(2- pyridylmethyl)aminomethyl]-4-methylphenol and L is CH₃(CH₂)_nCOO⁻ or Ph(CH₂)_nCOO⁻. The Mössbauer spectra of the mixed-valence complexes of L=CH₃(CH₂)_nCOO⁻ with n=0,1 and 2 consist of two quadrupole doublets due to high-spin iron(II) and high-spin iron(III). However, the complexes with n=3,4, 5, 6 and 7 show one quadrupole doublet at room temperature, which suggests a delocalized valence state. The complexes of L=Ph(CH₂)_nCOO⁻ with n=0,1,2 and 3 show localized valence states and those with n= 4 and 5 show a delocalized one.