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Abstract: A series of new polyoxometalates based on [Ni6(μ3-OH)3(H2O)6(en)3(B-α-PW9O34)] (en=ethylenediamine) clusters capped by different tripodal alcohol ligands have been hydrothermally synthesized and characterized by IR, TGA and single-crystal X-ray diffraction, respectively. The experimental results indicate that the tripodal alcohol ligands can substitute three hydroxyl groups located on the axial positions of the Ni6 cluster to form new polyoxometalates with different substituted modes. [Copyright &y& Elsevier]

A series of novel 4s–4f heterometallic cluster substituted polyoxometalates (POMs) with formula of H 9 Na 12 K 2 [K 3 Ln 4 (NO 3) 2 (GeW 10 O 37) 2 (Ge 2 W 18 O 66)]·34H 2 O (1-Ln) (Ln = Dy, Ho, Er) have been hydrothermally made by adopting a trilacunary [A-α-GeW 9 O 34 ]10− as a precursor. 1-Ln represent the first examples of metal-substituted POM clusters based on mixed POM fragments including dilacunary [α-GeW 10 O 37 ]10− and multilacunary open Well-Dawson [Ge 2 W 18 O 66 ]16− fragments. • Novel 4s–4f heterometallic substituted POMs have been prepared and characterized. • The compounds contain mixed Keggin/ open Well-Dawson POM fragments. • The Luminescent properties of these compounds were systematically studied. • The work enriches the diversity of heterometallic metal cluster substituted POMs. • This work provides a new route for making new POMs based on mixed POM units. By adopting a trilacunary [A-α-GeW 9 O 34 ]10− as a precursor under hydrothermal conditions, a series of novel 4s–4f cluster substituted polyoxometalates (POMs) containing two types of in situ generated lacunary POM fragments have been made. These compounds were characterized by single-crystal X-ray diffractions, powder X-ray diffractions, infrared spectroscopy, thermogravimetric analyses, respectively. Structural analyses indicate that these compounds constructed from a seven-nuclearity K-O-Ln (Ln = Dy, Ho, Er) heterometallic cluster stabilized by mixed dilacunary Keggin [α-GeW 10 O 37 ]10−/multilacunary open Wells-Dawson [Ge 2 W 18 O 66 ]16− fragments. Furthermore, the solid luminescent properties of the compounds at room temperature were studied. [ABSTRACT FROM AUTHOR]