New insights on the electronic, magnetic, electric and molecular structure of a bis-(4-cyanopyridine) iron(III) complex with the meso-tetrakis(4-methoxyphenyl)porphyrin

We have successfully synthesized and characterized a new low-spin iron(III) bis(4-cyanopyridine) complex with a meso-porphyrin substituted in the para positions of the phenyls by the methoxy group, namely the bis(4-cyanopyridine)[(meso-tetrakis(4-metoxyphenylporphyrinato)]iron(I II) trifluoromethanesulfonate chlorobenzene monosolvate complex with the formula [Fe-III(TMPP)(4-CNpy)(2)]SO3CF3 center dot C6H5Cl (I). This species was characterized through ultraviolet-visible, Fourier-transform infrared and Mossbauer spectroscopy as well as by SQUID magnetometry, cyclic voltammetry, and X-ray crystallography. These characterizations indicated that our synthetic heme model is a low-spin (S = 1/2) coordination compound and especially shows that the structural, electronic and the magnetic properties of complex (I) are closely dominated by the presence of the methoxy odonor group at the para positions of the meso-porphyrin.