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

Abstract Two novel 1,3-bis[tris(hydroxymethyl)methylamino]propane (H 6 L) functionalized 3d-4f heterometallic arsenotungstates (ATs) [H 2 N(CH 3 ) 2 ] 5 Na 2 H 4 [Cu(H 2 L)]{[Ln 0.5 Na 1.5 Cu 3 (H 2 O) 5 ](AsW 9 O 33 ) 2 }·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-α-AsW 9 O 33 ] 9− subunits sandwich an opening pentagonal metallocycle heterometallic cluster [Cu(H 2 L)Ln 0.5 Na 1.5 Cu 3 (H 2 O) 5 ] 7+ with the copper-organic group [Cu(H 2 L)] 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 H 2 SO 4 /Na 2 SO 4 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.