Synthesis and characterisation of triselenocarbonate [CSe3]2− complexes

Abstract

[Pt(CSe₃)(PR₃)₂] (PR₃ = PMe₃, PMe₂Ph, PPh₃, P(p-tol)₃, ½ dppp, ½ dppf) were all obtained by the reaction of the appropriate metal halide containing complex with carbon diselenide in liquid ammonia. Similar reaction with [Pt(Cl)₂(dppe)] gave a mixture of triselenocarbonate and perselenocarbonate complexes. [{Pt(µ-CSe₃)(PEt₃)}₄] was formed when the analogous procedure was carried out using [Pt(Cl)₂(PEt₃)₂]. Further reaction of [Pt(CSe₃)(PMe₂Ph)₂] with [M(CO)₆] (M = Cr, W, Mo) yielded bimetallic species of the type [Pt(PMe₂Ph)₂(CSe₃)M(CO)₅] (M = Cr, W, Mo). The dimeric triselenocarbonate complexes [M{(CSe₃)(η⁵-C₅Me₅)}₂] (M = Rh, Ir) and [{M(CSe₃)(η⁶-p-MeC₆H₄ⁱPr)}₂] (M = Ru, Os) have been synthesised from the appropriate transition metal dimer starting material. The triselenocarbonate ligand is Se,Se′ bidentate in the monomeric complexes. In the tetrameric structure the exocyclic selenium atoms link the four platinum centres together.