New Synthesis of [SFe₃(CO)₉]²^-and Its Reactivity toward Electrophiles

Abstract

The reaction of Na2SO3 with Fe(CO)5/KOH in methanol forms the tetrahedral cluster [SFe3(CO)9]2- in good yield. Acidification of [SFe3(CO)9]2- with H+ forms the monohydrido cluster [SFe3(μ-H)(CO)9]- (I) and the dihydrido cluster SFe3(μ-H)2(CO)9. Further methylation of [SFe3(CO)9]2- with MeSO3CF3 produces the sulfur-methylated cluster [MeSFe3(CO)9]- (II). When [SFe3(CO)9]2- is treated with Ru3(CO)12 in refluxing acetone, the octahedral cluster [SFe2Ru3(CO)14]2- (III) is obtained. Subsequent methylation of III with MeSO3CF3 gives the octahedral cluster [MeSFe2Ru3(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 [SFe3(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.