The synthesis, structure, spectra, and reactivity of diamagnetic linear chain heterotrinuclear ore-bridged complexes L-(FeN4)-N-III-O-Ru-IV(TPP')-O-(FeN4)-N-III-L are described where TPP' is tetrakis(4-methoxyphenylporphyrinate), N-4 is one of the borylated bis(dioximate) macrocycles, N-4 = ((DMG)BF2)(2) in 1, ((DMG)BPh2)(2) in 2, and ((DPG)BF2)(2) in 3, and L is a monodentate terminal ligand, L = BuNH2, CH3CN, Py, 1-MeIm, (BuO)(3)P, etc. Crystal data for 3-(BuNH2)(2) = [(BuNH2)Fe((DPG)BF2)(2)-O](2)Ru(TPP') monoclinic space group P2(1)/n, a = 16.845 Angstrom, b = 27.184 Angstrom, c = 24.593 Angstrom, beta = 90.41 degrees, Fe-O = 1.79(1) Angstrom, Ru-O = 1.80(1) Angstrom, Fe-O-Ru = 175 degrees. Large porphyrin and phenyl ring current shifts permit ready characterization of the materials by H-1 NMR. A redshifted Soret band at 433 nm and two charge transfer transitions in the 650-850 nm region are observed in the visible spectra. Clean reduction of 1, 2, and 3-(CH3CN)2 with 4-tert-butylcatechol is observed giving Fe(II) and Ru(II) products. The kinetics of reduction parallel those of low-spin (mu-oxo)diiron FeN4 systems showing a 1/[CH3CN] dependence, but the rates are 10(3)-10(5) times slower. The Ru-IV is proposed to stabilize the mu-oxo-Fe bonds toward reductive cleavage via delocalization of the oxo pi electrons onto the ruthenium. Electrochemical data for the heterotrinuclear Fe-O-Ru-O-Fe systems are compared with those for the binuclear Fe-O-Fe systems. The HOMO is stabilized by 120 mV over the corresponding Fe-O-Fe system.