Two 3d–4f heterometallic monovacant Keggin phosphotungstate derivatives

Abstract

Two 3d–4f heterometallic monovacant Keggin phosphotungstate derivatives [Cu(dap)(H₂O)₂]_0.5[Cu(dap)₂]₄H₂[Pr(α-PW₁₁O₃₉)₂] · 3H₂O (1) and [Cu(en)₂(H₂O)]₂[Cu(en)₂]_1.5H₄[Pr(α-PW₁₁O₃₉)₂] · 10H₂O (2) (dap = 1,2-diaminopropane, en = ethylenediamine) have been hydrothermally synthesized by reaction of the trivacant Keggin phosphotungstate precursor Na₉[A-α-PW₉O₃₄] · 7H₂O with CuCl₂ · 2H₂O and PrCl₃ in the presence of dap or en and structurally characterized by elemental analyses, IR spectra, X-ray single-crystal diffraction, and thermogravimetric analyses. Compound 1 crystallizes in the triclinic space group P 1 with a = 17.325(3), b = 18.917(3), c = 19.938(3) Å, α = 104.481(2), β = 98.968(3), γ = 91.306(3)°, V = 6236.4(18) ų, Z = 2, GOOF = 1.000, R ₁ = 0.0806, wR ₂ = 0.2016. Compound 2 also belongs to the triclinic space group P 1 with a = 16.005(4), b = 18.053(4), c = 21.127(5) Å, α = 113.894(3), β = 90.745(4), γ = 94.255(4)°, V = 5560(2) ų, Z = 2, GOOF = 0.999, R ₁ = 0.0686, wR ₂ = 0.1885. Both 1 and 2 display organic–inorganic hybrid 2-D sheet architectures built by classic mono-Pr^III sandwiched dimeric moieties [Pr(α-PW₁₁O₃₉)₂]¹¹⁻ through [Cu(L)₂]²⁺ bridges (L = dap, en), which represent rare organic–inorganic hybrid 2-D 3d–4f heterometallic monovacant Keggin polyoxometalates.

Keywords:

• Polyoxometalate
• Phosphotungstate
• 3d–4f Heterometal
• Lanthanide

Acknowledgments

We are thankful for financial support from the Natural Science Foundation of China (nos 21071043, 21071042), China Postdoctoral Science Foundation funded project (20100470996), the Natural Science Foundation of Henan Province (nos 092300410119, 102300410093), the Natural Science Foundation of Henan University (no. 2008YBZR010), the Postdoctoral Science Foundation of Henan University (no. BH2010003), the Foundation of Education Department of Henan Province (nos 2009A150003, 2010B150006), and Students Innovative Pilot Plan of Henan University (no. 09NB005).