A new μ-oxodiiron(III) complex [{FeIII(bpc)(H2O)}2O] (1) with the bis(picolinamide) N4 in-plane ligand 4,5-dichloro-1,2-bis(pyridine-2-carboxamido)benzene (H2bpc) has been prepared by the reaction of [Fe(bpc)Cl(H2O)] with a stoichiometric amount of cyanide, and characterized by X-ray structure analysis. The IR and UV/Vis spectroscopic results match well with those expected from the respective previously established spectro-structure correlation. Likewise, the temperature dependence of the magnetic susceptibility shows the existence of a strong antiferromagnetic coupling between the iron(III) centers [S = 5/2; with J = –108.10(3) cm–1] that is consistent with the radial and angular overlap Weihe–Güdel model in μ-oxodiiron(III) complexes. Two heterometallic FeIII-CuIIFeIII (2) and FeIIINiIIFeIII (3) complexes have been prepared from the reaction between [FeIII(bpc)(N3)2] and [Cu(meso-CTH)]2+ or [Ni(meso-CTH)]2+ (CTH = 5,7,7,12,14,14-hexamethyl-1,4,8,11-tetraazacyclotetradecane), respectively. The structure of 2 consists of heterometallic FeIIICuIIFeIII units formed by the simultaneous coordination of two [FeIII(bpc)(N3)2] units to the central [Cu(meso-CTH)] units through a μ1,3-azide bridging ligand. However, the structure of 3 contains isolated [FeIII(bpc)(N3)2]– and [Ni(meso-CTH)]2+ ions. The treatment of the magnetic data of 2 revealed the existence of a small ferromagnetic interaction between FeIII and CuII metal ions, with JFeCu = 3.24(7) cm–1. The existence of 2 opens up the possibility of obtaining, in a rational manner, azide-bridged heterometallic complexes starting from the block precursor [FeIII(bpc)(N3)2]–. (© Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2005)