Isolation and structural characterization of complexes formed in the reactions of [{C5H4(SiMe(3))}(2)Fe-2(CO)(4)] and [{1,3-C5H3(SiMe(3))(2)}(2)Fe-2(CO)(4)] with elemental sulfur

The reactions of [Cp(2)(S1)Fe(2)(CO)(4)] and [Cp(2)(S2)Fe(2)(CO)(4)] with elemental sulfur afforded a tetrairon cluster containing two end-on type S-2 ligands [Cp(4)(S1)Fe(4)S(6)] (1) and a diiron complex containing an end-on type S-2 and a side-on type S-2 ligands [(CP2Fe2S4)-Fe-S2] (2), respectively, where Cp(S1) and Cp(S2) stand for mono- and bis(trimethylsilyl)cyclopentadienyl ligands, respectively. From these results and the previously reported results which were obtained for the reactions of [Cp(2)Fe(2)(CO)(4)] and [CP*Fe-2(2)(CO)(4)] with elemental sulfur, it is suggested that [Cp'2Fe2S4] is an intermediate to give tetrairon sulfur clusters, where Cp* and Cp' denote pentamethylcyclopentadienyl and substituted cyclopentadienyl ligands, respectively. X-Ray crystal structure analysis was carried out for the compounds 1 and 2. Crystallographic data are as follows: 1: Monoclinic, P2(1)/c, a = 17.302(6), b = 18.646(3), c = 15.310(4) Angstrom, beta = 120.71(2)degrees, V = 4246(2) Angstrom(3), Z = 4, and R = 0.061 for 5850 reflections with \F-o\ > 3 sigma(F-o; 2: Triclinic, space group <P(1)over bar>, a = 12.602(2), b = 12.891(2), c = 11.401(1) Angstrom, alpha = 114.52(1), beta = 95.45(1), gamma = 88.39(1)degrees, V = 1677.5(4) Angstrom(3), Z = 2, and R = 0.046 for 7343 reflections with \F-o\ > 3 sigma(F-o).