{Cu₈} Cluster-Sandwiched Polyoxotungstates and Their Polymers: Syntheses, Structures, and Properties

Abstract

Four inorganic−organic hybrid octa-Cu cluster sandwiched polyoxotungstates (POTs), [Cu 8 4) (en = ethylenediamine), were hydrothermally made and characterized by single-crystal X-ray diffraction, infrared spectra, powder X-ray diffraction, and thermogravimetric analysis, respectively. Structure analysis reveals that the polyoxoanion of 1/2 is a discrete dimer built by two trivalent Keggin [B-α-XW 9 O 34 ] 10− (X = Si/ Ge) fragments and one octa-Cu cluster, whereas 3 and 4 display a twodimensional network built by octa-Cu-sandwiched POT units via substitution of coordinated water on polyanions of 1 and 2 and further expand into a three-dimensional framework via K cation bridges. Ultraviolet−visible diffuse reflectance spectra reveal that 1−4 are potential semiconductor materials. Moreover, its visible light-driven catalytic H 2 evolution activity, electrochemical properties, catalysis for oxygenation reactions of thioethers, and magnetic behaviors have been investigated in detail.

Hepta-Zr-Incorporated Polyoxometalate Assembly

“…Compared with these catalysts, the new catalyst 1 simultaneously exhibited distinguished conversion, outstanding yield, and good recyclability for the complete oxidation to sulfone with the assistance of the green oxidant H 2 O 2 under mild conditions. Moreover, the catalytic efficiency of 1 is superior to that of most transition metal substituted POMs reported previously. ,,, …”

“…Moreover, the catalytic efficiency of 1 is superior to that of most transition metal substituted POMs reported previously. 21,32,60,61 As proposed in the reaction mechanism (Figure S10), we speculated that the oxidant H 2 O 2 could react with POMs to obtain the active electrophilic peroxide intermediates, which facilitated the oxidation process. As the sulfides or sulfoxides captured oxygen atoms, the peroxide POM intermediates were reduced to the original POMs for the next cycles.…”

Four POM-based complexes modified by multi-nuclear clusters: structure, photocatalytic, supercapacitor and chromogenic properties

“…The electrochemical properties of complexes 1–4 have been studied in 0.1 M H 2 SO 4 + 0.5 M Na 2 SO 4 aqueous solution. 30 We used 1 -, 2 - and 4 -CPEs as examples, owing to the similar electrochemical behaviors between 2 - and 3 -CPEs. Fig.…”

Assembly of a Hexameric Cluster of Polyoxomolybdotriphosphonate Builts from [Zn(H2O){TeMo6O21}{N(CH2PO3)3}]6– Subunits and Its Optical and Catalytic Properties

“…In addition, IR spectra (Figure S19) and PXRD patterns (Figure S20) confirmed that 1 could maintain its structural integrity after catalytic reactions. Finally, in light of previous literature reports , and our results, a plausible oxidation mechanism has been summarized in Scheme S2.…”