Bis(pentafluorophenyl)nickel(II) thio-molybdates and -tungstates. Crystal structure of [NBu4]2[Ni2(C6F5)4(µ-WS4)]

Abstract

The complexes [NBu₄]₂[Ni₂(C₆F₅)₄(µ-MS₄)](M = Mo 1 or W 2) have been prepared by reaction of [NBu₄]₂[Ni₂(C₆F₅)₄(µ-OH)₂] with [NH₄]₂[MS₄] in ethanol in 1 : 1 molar ratio. When the bis(hydroxo) complex was treated with [NH₄]₂[MO_{4 –n}S_n] and NBu₄OH the complexes [NBu₄]₂[Ni(C₆F₅)₂(µ-MO_{4 –n}S_n)](M = Mo, n= 4 3, 3 4, or 2 5; M = W, n= 4 6 or 2 7) were obtained. Conductance and spectroscopic (IR and ¹⁹F NMR) measurements have been made. In complexes 1 and 2 two Ni(C₆F₅)₂ subunits are bridged by a tetradentate bridging MS₄^2– anion, whereas a bidentate terminal S-bonded MO_{4 –n}S_n^2– anion is present in 3–7. A single-crystal X-ray diffraction study has established that the anion of complex 2 consists of a central S₂WS₂ tetrahedral subunit bridging two terminal square-planar Ni(C₆F₅)₂ subunits.