Zhang, Jing, Yu, Hao, Gu, Ya-Nan, Li, Zhong, Li, Xin-Xiong, Li, Ling-Yun, and Zheng, Shou-Tian
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]