Two diiron ethane-1,2-dithiolate complexes were prepared and structurally characterized. Reactions of the parent complex [Fe2(CO)6(μ-SCH2CH2S)] (1) with tris(4-trifluoromethylphenyl)phosphine or triethyl phosphite and Me3NO·2H2O as the oxidative reagent resulted in the formation of the phosphine-substituted analog [Fe2(CO)5{P(4-C6H4CF3)3}(μ-SCH2CH2S)] (2) and phosphite-substituted analogue [Fe2(CO)5{P(OCH2CH3)3}(μ-SCH2CH2S)] (3) in 84% and 78% yields, respectively. The new complexes 2 and 3 were characterized by elemental analysis, IR, NMR spectroscopy, and single crystal X-ray diffraction analysis. Moreover, the electrochemical properties of both complexes were studied by cyclic voltammetry.