Organosulphur–transition-metal chemistry. Part 1. Reactions of carbon disulphide with metal carbonyl anions

Abstract

The trithiocarbonato-complex [N(PPh3)2][Mn(CO)4(S2CS)] is formed in high yield on treatment of [N(PPh3)2][ Mn(CO)5] with CS2 in tetrahydrofuran (thf) over 4 d. Reactions also occur between CS2 and the iminium salts of [Re(CO)5]– and [Mo(CO)3(η-C5H5)]– but no products have been isolated. Methylation of [N(PPh3)2][ Mn(CO)4(S2CS)] with either Mel or SFO2(OMe) gives [Mn(CO)4(S2CSMe)] in ca. 40% yield, but GeBrMe3 or [PhN2][BF4] provide [Mn(CO)4(S2CSMe)] and [Mn(CO)4(S2CSPh)], respectively, in only small amounts. Low (<10%) yields of trithiocarbonato-complexes are produced when thf solutions of sodium salts of [M(CO)5]–(M = Mn or Re), [Fe(CO)2(η-C5H5)]–, [Mo(CO)3(η-C5H5)]–, and [M(CO)4]2–(M = Fe, Ru, or OS) are treated with CS2 and Mel consecutively. Very small amounts of dimetal complexes [(OC)4M(µ-S2CS)M(CO)5](M = Mn or Re) have also been isolated from reactions of [M(CO)5]– with CS2 and Mel, with [graphic omitted](SMe) as an additional product from Na[Mn(CO)5]. The complex [(OC)4Re(µ-S2CS)Re(CO)5] is better obtained (45% yield) when Na[Re(CO)5] is treated successively with CS2 and [ReBr(CO)5]. Analogous complexes [(OC)4Mn(µ-S2CS)Re(CO)5] and [(OC)4Re(µ-S2CS)Mn(CO)5] are similarly prepared. The effect of added sulphur on various reactions is described. Addition to [N(PPh3)2][Mn(CO)5] causes an immediate colour change from yellow to red, i.r. spectroscopic evidence for the formation of [N(PPh3)2][MnSn(CO)5] being obtained. With CS2 this species generates [N(PPh3)2][Mn(CO)4(S2CS)] slowly, while Mel gives [N(PPh3)2][MnI2(CO)4]. Possible mechanisms of trithiocarbonato-complex formation from CS2 are discussed.