(MU-NITRIDO)((TETRAPHENYLPORPHYRINATO)IRON) AND ITS FE-RU ANALOG - REDOX BEHAVIOR AND CHARACTERIZATION OF NEW FE(IV)-CONTAINING SPECIES - X-RAY CRYSTAL-STRUCTURE OF [(THF)(TPP)FE-N-FEPC(H2O)](I-5).2THF

The mixed-ligand bimetallic N-bridged, formally mixed-valence Fe(III)- Fe(IV) species (TPP)Fe-N-FePc, previously reported, and the heterobime tallic analogue (TPP)Fe-N-RuPc have been prepared and characterized, a nd their redox properties have been examined. Oxidation of these speci es with I-2 leads in both cases to monopositively charged Fe-Fe and Fe -Ru mu-nitrido dimers, having I-5(-) as counterion. By reaction with N aBH4, these salt-like species are reduced to the starting materials. T he structure of the complex [(THF)(TPP)Fe-N-FePc(H2O)](I-5) . 2THF has been elucidated by an X-ray study. The complex crystallizes in the mo noclinic system. Unit cell data: formula C88H70Fe2I5N13O4, M = 2119.94 , a = 27.13(1) Angstrom, b = 12.032(5) Angstrom, c = 25.596(41) Angstr om, V = 8298(20) Angstrom(3), Z = 4, space group Cc. The structure sho ws that the phthalocyanine and tetraphenylporphyrin rings are held tog ether by the nearly linear triatomic Fe-N-Fe moiety (179 degrees). Eac h Fe atom within the molecule lies in the plane of the respective macr ocycle, six-coordination being achieved by external axial ligation of H2O and THF molecules at the PcFe and (TPP)Fe sites, respectively. The H2O molecule is hydrogen-bonded to two additional THF molecules. The I-5(-) ion is V-shaped and lies separately in the crystal. Additional information on the molecular and electronic structure of the present F e-Fe and Fe-Ru species has been obtained from IR, Raman, Mossbauer, an d EPR spectra and also from magnetic susceptibility data.