Carboxy-functionalized dithiolate di-iron complexes related to the active site of Fe-only hydrogenase

New carboxy-functionalized di-iron compounds have been synthesized by addition of dihalide derivatives (XCH2)2R [X = Cl, R = NC6H4CH2CO2CH3; X = Br, R = C6H3COOH, C6H3COON(COCH2)2] to dinuclear anionic species [Fe2(μ-S)2(CO)6]2−.