Reactions of tetrathiotungstate and tetrathiomolybdate with substituted haloalkanes

Abstract

Reactions of [PPh₄]₂[WS₄] in CH₃CN with excess n-hexylbromide, 1,4-dichlorobutane, 2-(bromomethyl)tetrahydro-2H-pyran) (bmthp), and 2-(bromoethyl)-1,3-dioxane (bedo) followed by extraction with THF afforded a series of alkylthiolatotrithiotungstate complexes, [PPh₄][(RS)WS₃] (1: R = n-hexyl; 2: R = ClCH₂CH₂CH₂CH₂; 3: R = mthp; 4: R = edo), and the analogous reactions of [PPh₄]₂[MoS₄] in CH₃CN–THF with excess bmthp and bedo also generated [PPh₄][(RS)MoS₃] (5: R = mthp; 6: R = edo), albeit in low yields. Treatment of [PPh₄]₂[WS₄] in CH₃CN with excess (S)-(+)-3-bromo-2-methyl-1-propanol turned out to give a trinuclear, [PPh₄]₂[W₃S₈((S)-(+)-OCH₂CH(Me)CH₂Br)₂] (7). Compounds 1–7 were characterized spectroscopically and the crystal structures of 2–7 were determined by X-ray analysis. All the mononuclear complexes 2–6 assume tetrahedral structures, being coordinated by one thiolate sulfur and three terminal sulfido ligands, and no additional coordination was observed by the O-donor portions of mthp or edo. The structure of 7 consists of a linear W₃ spine and two (S)-(+)-OCH₂CH(Me)CH₂Br ligands are coordinated at the central W atom.