Inorganic Chemistry, Vol.35, No.4, 898-905, 1996
Synthesis and Chemical and Electrochemical Characterization of Fe-S Carbonyl Clusters - X-Ray Crystal-Structures of (N(Pph(3))(2))(2)(Fe5S2(Co)(14)) and (N(Pph(3))(2))(2) (Fe6S6(Co)(12))
A reinvestigation of the redox behavior of the [Fe-3(mu(3)-S)(CO)(9)](2-) dianion led to the isolation and characterization of the new [Fe5S2(CO)(14)](2-), as well as the known [Fe6S6(CO)(12)](2-) dianion. As a corollary, new syntheses of the [Fe3S(CO)(9)](2-) dianion are also reported. The [Fe5S2(CO)(14)](2-) dianion has been obtained by oxidative condensation of [Fe3S(CO)(9)](2-) induced by tropylium and Ag(I) salts or SCl2, or more straightforwardly through the reaction of [Fe-4(CO)(13)](2-) with SCl2. The [Fe6S6(CO)(12)](2-) dianion has been isolated as a byproduct of the synthesis of [Fe3S(CO)(9)](2-) and [Fe5S2(CO)(14)](2-) or by reaction of [Fe-4(CO)(13)](2-) with elemental sulfur. The structures of [N(PPh(3))(2)](2)[Fe5S2(CO)(14)] and [N(PPh(3))(2)](2)[Fe6S6(CO)(12)] were determined by single-crysta3))(2)](2)[Fe5S2(CO)(14)], monoclinic, space group P2(1)/c (No. 14), a = 24.060(5), b = 14.355(6), c = 23.898(13) Angstrom, beta = 90.42(3)degrees, Z = 4; for [N(PPh(3))(2)](2)[Fe6S6(CO)(12)], monoclinic, space group C2/c (No. 15), a = 34.424(4), b = 14.081(2), c = 19.674(2) Angstrom, beta = 115.72(1)degrees, Z = 4. The new [Fe5S2(CO)(14)](2-) dianion shows a "bow tie" arrangement of the five metal atoms. The two Fe-3 triangles sharing the central Fe atom are not coplanar and show a dihedral angle of 55.08(3)degrees. Each Fe-3 moiety is capped by a triply bridging sulfide ligand.
Keywords:CHARACTERIZED REDOX CHANGES;METAL-SULFUR CLUSTERS;STEREOCHEMICAL CONSEQUENCES;COORDINATION CHEMISTRY;OXO CLUSTER;COMPLEXES;BEHAVIOR;LIGANDS