CORRELATION BETWEEN THE RATE OF INTRAMOLECULAR ELECTRON-TRANSFER OF DINUCLEAR IRON COMPLEXES(II,III) AND THE PHASES OF THE MOLECULAR-STRUCTURES

Dinuclear iron(II, III)complexes with a hexadentate ligand [Fe(2)bpmp( L)(2)](BF4)(2) were prepared, where Hbpmp represents s[bis(2-pyridylym ethyl)aminomethyl]-4-methylphenol and L is CH3(CH2)(n)COO- or Ph(CH2)( n)COO-. The Mossbauer spectra of the mixed-valence complexes of L=CH3( CH2)(n)COO- with n=0, 1 and 2 consist of two quadrupole doublets due t o high-spin iron(II) and high-spin iron(III). However, the complexes w ith 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(CH 2)(n)COO- with n=0, 1, 2 and 3 show localized valence states and those with n=4 and 5 show a delocalized one.