Reaction of [NH4]2[WSe4] dissolved in DMF with a suspension of Ni(acac)2in DMF in the presence of [PPh4]Cl affords [PPh4]2[Ni(Se2)(WSe4)]. A similar reaction involving NiCl2(PPh3)2in place of Ni(acac)2affords [PPh4]2[Ni(WSe4)2], while the use of PdCl2(C6H5CN)2affords [PPh4]2[Pd(WSe4)2]. The Ni(Se2)(WSe4)2- ion shows77Se NMR resonances at δ 1399, 855, and 608 ppm expected for the structure found in the solid state consisting of a square-planar Ni center bound to a side-on Se2group and to a nearly tetrahedral WSe4group ([PPh4]2[Ni(Se2)(WSe4)], Z = 4, P21/n, a = 14.222 (6) Å, b = 17.168 (7)Å, c = 19.976 (8) Å, β= 110.3 (2)°, R(F2) = 0.076 for 9932 observations). This ion has no known sulfide analogue. The M(WSe4)2 2_ions (M = Ni, Pd) are closely analogous to the known Ni(WS4)2 2_ion and show two77Se NMR resonances (Ni 1628, 994 ppm; Pd 1673, 1135 ppm) consistent with the structure found in the solid state for [PPh4]2[Ni(WSe4)2] in which the square-planar Ni center is bound to two nearly tetrahedral WSe4centers (Z = 1, PI, a = 9.347 (3) Å, b = 12.410 (3) Å, c = 12.557 (3) Å, α = 65.76 (1)°, β = 84.61 (2)°, γ = 69.83 (2)°, R(F2) = 0.090 for 7295 observations). While the Pd(WSe4)2 2-ion is stable in DMF solution at room temperature, the corresponding Ni(WSe4)2 2-ion decomposes to form the Ni(Se2)(WSe4)2-ion.
ASJC Scopus subject areas
- Physical and Theoretical Chemistry
- Inorganic Chemistry