Reactions of a dinuclear tungsten complex containing an O-co-ordinated bridging ketene with various heterocumulenes

Abstract

Treatment of the dinuclear O-co-ordinated ketene complex W₂Cp₂(CO)₅(µ-η¹∶η²-CH₂CO) (Cp = η⁵-C₅H₅) with PhCH₂NCS afforded the dark red bridging thioketene complex W₂Cp₂(CO)₅(µ-η³-SCCH₂). Reaction of the latter with HBF₄ gave the stable cationic product [W₂Cp₂(CO)₅(µ-SCMe₃)]BF₄ by addition of a proton to the terminal carbon of the thioketene group. In the reaction of W₂Cp₂(CO)₅(µ-η¹∶η²-CH₂CO) with CS₂ cleavage of one CS bond is accompanied by insertion of the resulting sulfur atom into the tungsten-acyl bond to afford W₂Cp₂(CO)₅(CS)(µ-CH₂COS). The Cp′ analogue (Cp′ = η⁵–C₅H₄Me) was also prepared. The reaction of the trithiocarbonate SC(SCH₂)₂ with W₂Cp₂(CO)₅(µ-η¹∶η²-CH₂CO) afforded the carbene complex W₂Cp₂(CO)₅[C(SCH₂)₂](µ-CH₂COS), and with allene gave the allylic complex W₂Cp₂(CO)₅(µ-η¹∶η³-CH₂COC₃H₄). Those of the complexes have been characterized by single crystal X-ray diffraction analysis.