The cluster derivatives of the type [Fe-3(mu(3)-S)(2)(CO)(8)L] or [Fe-3(mu(3)-S)(2)(CO)(7)L] (L = phosphine ligands) have been prepared by carbonyl substitution reactions of [Fe-3(mu(3)-S)(2)(CO)(9)] (A) with monophosphine PPh3 or diphosphine Ph2PCH2PPh2. Reaction of complex A with PPh3 in the presence of Me3NO center dot 2H(2)O in MeCN afforded [Fe-3(mu(3)-S)(2)(CO)(8)PPh3] (1) in 65% yield, whereas reaction of A with PPh3 at reflux in toluene gave 1 and [Fe-3(mu(3)-S)(2)(CO)(7)(PPh3)(2)] (2) in 36% and 42% yields, respectively. However, complex [Fe-3(mu(3)-S)(2)(CO)(7)(Ph2PCH2PPh2)] (3) could be prepared by two methods: (i) reaction of A with Ph2PCH2PPh2 in the presence of Me3NO center dot 2H(2)O in MeCN in 54% yield; and (ii) reaction of A with Ph2PCH2PPh2 at reflux in toluene in 37% yield. The cluster complexes 1-3 were structurally characterized by elemental analysis, IR and NMR spectroscopic analysis. In addition, the molecular structures of 1 and 3 were determined by X-ray crystallography. [Supplemental materials are available for this article. Go to the publisher's online edition of Molecular Crystals and Liquid Crystals to view the free supplemental file.]