Abstract
The reaction of Na 2 SO 3 with Fe(CO) 5 /KOH in methanol forms the tetrahedral cluster [SFe 3 (CO) 9 ] 2- in good yield. Acidification of [SFe 3 (CO) 9 ] 2- with H + forms the monohydrido cluster [SFe 3 (μ-H)(CO) 9 ] - (I) and the dihydrido cluster SFe 3 (μ-H) 2 (CO) 9 . Further methylation of [SFe 3 (CO) 9 ] 2- with MeSO 3 CF 3 produces the sulfur-methylated cluster [MeSFe 3 (CO) 9 ] - (II). When [SFe 3 (CO) 9 ] 2- is treated with Ru 3 (CO) 12 in refluxing acetone, the octahedral cluster [SFe 2 Ru 3 (CO) 14 ] 2- (III) is obtained. Subsequent methylation of III with MeSO 3 CF 3 gives the octahedral cluster [MeSFe 2 Ru 3 (CO) 14 ] - (IV), in which the sulfur atom is pentacoordinated to one methyl group and two Ru and two Fe atoms. Clusters I-IV have been fully structurally characterized by spectroscopic methods and X-ray analysis. In this paper, the basic sites of [SFe 3 (CO) 9 ] 2- are studied in terms of the differing electrophiles, and a novel pentacoordinate bonding mode of the sulfur atom is also found in cluster IV.