Two 1,3-bis[tris(hydroxymethyl)methylamino]propane functionalized 3d-4f heterometallic arsenotungstates

Two novel 1,3-bis[tris(hydroxymethyl)methylamino]propane (H6L) functionalized 3d-4f heterometallic arsenotungstates (ATs) [H2N(CH3)(2)](5)Na2H4[Cu(H2L)]{[Ln(0.5)Na(1.5)Cu(3)(H2O)(5)](AsW9O33)(2)}center dot 17H(2)O [Ln = Ho-III (1), Yb-III (2)] have been synthesized in conventional aqueous solution by using simple materials and further characterized by elemental analyses, IR spectra, thermogravimetric analyses, powder X-ray diffraction spectra and single-crystal X-ray diffraction. The most prominent structural feature of 1 and 2 is that two trivacant Keggin [B-alpha-AsW9O33](9-) subunits sandwich an opening pentagonal metallocycle heterometallic cluster [Cu(H2L) Ln(0.5)Na(1.5)Cu(3)(H2O)(5)](7+) with the copper-organic group [Cu(H2L)](2-). The UV absorption spectra illustrate that 1 is stable in the pH range of 2.48-8.02. The solid-state electrochemical properties of 1 have also been measured in 0.5 mol.L-1 H2SO4/Na2SO4 aqueous solution by entrapping it in a glass carbon electrode. Furthermore, the variable-temperature magnetic susceptibility of 1 shows the weak Cu-II - Ho-III ferromagnetic interactions.