posted on 2021-06-28, 13:36authored byJun-Jun Sun, Wei-Dong Wang, Xu-Yan Li, Bai-Feng Yang, Guo-Yu Yang
Four
inorganic–organic hybrid octa-Cu cluster sandwiched
polyoxotungstates (POTs), [Cu8(H2O)2(en)4(B-α-H2SiW9O34)2] (1), [Cu8(H2O)2(en)4(B-α-H2GeW9O34)2] (2), K2[Cu8(en)4(B-α-HSiW9O34)2]·6H2O (3), and K2[Cu8(en)4(B-α-HGeW9O34)2]·2H2O (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-XW9O34]10– (X = Si/Ge) fragments and one octa-Cu cluster, whereas 3 and 4 display a two-dimensional 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
H2 evolution activity, electrochemical properties, catalysis
for oxygenation reactions of thioethers, and magnetic behaviors have
been investigated in detail.