The title complex was synthesized by the reaction of (mu-SCH2CH2CH2S-)Fe-2(CO)(6) with tris(4-methoxyphenyl)phosphine in the presence of the decarbonylating agent Me3NO center dot 2H(2)O in CH2Cl2/MeCN solutions. The molecular structure was analyzed by X-ray diffraction analysis. The title complex contains a butterfly diiron dithiolate cluster with five terminal carbonyls and a tris(4-methoxyphenyl)phosphine. The phosphorus atom of tris(4-methoxyphenyl)phosphine resides in an apical position of the square-pyramidal geometry of the neighboring Fe2 atom. Intermolecular CH center dot center dot center dot O hydrogen bonds between the phenyl and carbonyl groups stabilize the solid state in the crystal packing.