Syntheses, structures, and properties of the bis(cyclopentadienyl) rare-earth imidodiphosphinochalcogenido compounds Cp₂Ln[N(QPPh₂)₂] (Ln = La, Gd, Er, or Yb for Q = Se; Ln = Yb for Q = S)

The compounds Cp₂Ln[N(QPPh₂)₂] (Ln = La (1), Gd (2), Er (3), or Yb (4) for Q = Se, Ln = Yb (5) for Q = S) have been synthesized from the corresponding rare-earth tris(cyclopentadienyl) compound and H[N(QPPh₂)₂]. The structures of compounds 1, 2, 3, and 5, as determined by X-ray crystallography, consist of a Cp₂Ln fragment, coordinated η³ through two chalcogen atoms and an N atom of the imidodiphosphinochalcogenido ligand [N(QPPh₂)₂]^-. In compound 4, the Cp₂Yb moiety is coordinated η² through the two Se atoms of the [N(SePPh₂)₂]^- ligand. ³¹P and ⁷⁷Se (for 1) NMR spectroscopies lend insight into the solution nature of these species. Crystal data: 1, C₃₄H₃₀LaNP₂Se₂, triclinic, P1, a = 9.7959(10) Å, b = 12.4134(13) Å, c = 13.9077(14) Å, α = 88.106(2)°, β = 88.327(2)°, γ = 68.481(2)°, V = 1572.2(3) ų, T = 153 K, Z = 2, and R₁(F) = 0.0257 for the 5947 reflections with I > 2σ(I); 2, C₃₄H₃₀GdNP₂Se₂, triclinic, P1, a = 9.7130(14) Å, b = 12.2659(17) Å, c = 13.953(2) Å, α = 88.062(2)°, β = 87.613(2)°, γ = 69.041(2)°, V = 1550.7(4) ų, T = 153 K, Z = 2, and R₁(F) = 0.0323 for the 5064 reflections with I > 2σ(I); 3, C₃₄H₃₀ErNP₂Se₂, triclinic, P1, a = 9.704(2) Å, b = 12.222(3) Å, c = 13.980(4) Å, α = 88.230(4)°, β = 87.487(4)°, γ = 69.107(4)°, V = 1547.4(7) ų, T = 153 K, Z = 2, and R₁(F) = 0.0278 for the 6377 reflections with I > 2σ(I); 4, C₃₄H₃₀NP₂Se₂Yb·C₄H₈O, triclinic, P1, a = 12.087(4) Å, b = 12.429(4) Å, c = 23.990(7) Å, α = 89.406(5)°, β = 86.368(5)°, γ = 81.664(5)°, V = 3558.8(18) ų, T = 153 K, Z = 4, and R₁(F) = 0.0321 for the 11 883 reflections with I > 2σ(I); and 5, C₃₄H₃₀NP₂S₂Yb, monoclinic: P2₁/n, a = 13.8799(18) Å, b = 12.6747(16) Å, c = 17.180(2) Å, β, = 91.102(3)°, V = 3021.8(7) ų, T = 153 K, Z = 4, and R₁(F) = 0.0218 for the 6698 reflections with I > 2σ(I).