Single-Molecule Magnetic, Catalytic and Photoluminescence Properties of Heterometallic 3d-4f [Ln{PZn2W10O38(H2O)2}2]11- Tungstophosphate Nanoclusters

A series of eleven lanthanide containing di-Zinc (II) substituted heterometallic 3d-4f sandwich-type tungstophosphate nanoclusters [Ln{PZn2W10O38(H2O)(2)}(2)](11-) (Ln=Nd-III, Sm-III, Eu-III, Gd-III, Tb-III, Dy-III, Ho-III, Er-III, Tm-III, Yb-III, and Lu-III) have been synthesized by a single step reaction procedure. These clusters were characterized by various analytical techniques such as single crystal X-ray diffraction (SC-XRD), fourier transform infrared (FT-IR) spectroscopy, high-resolution electro-spray ionization mass spectrometry (HR-ESI-MS), inductively coupled plasma atomic emission spectroscopy (ICP-AES), solid UV/Vis, photoluminescence spectroscopy, powder X-ray diffraction (P-XRD) and thermogravimetric analysis (TGA). All the polyanions are isostructural and consists of a lanthanide ion sandwiched between two units of (1,5) isomer of di-Zn substituted alpha-Keggin type tungstophosphate. The complexes Sm-2 a, Eu-3 a, Tb-5 a, and Dy-6 a show good photoluminescence behavior. The catalytic properties were examined for the oxidation of thioethers. The catalyst is stable with a high turn over frequency (TOF) of 6250 h(-1) and can be recovered even after 5 consecutive cycles. Furthermore, magnetic properties revealed that Gd-4 a, Tb-5 a, Dy-6 a, Er-8 a, and Yb-10 a show single-molecule magnetic properties.