Synthesis and characterization of a three-dimensional framework built up of paradodecatungstate-B clusters and transition metals as linkers

Iron(II) and copper(II) paratungstates B: a single-crystal X-ray diffraction study

“…In the IR spectra of Na 5 Fe 2.5 paraB and Na 4 Cu 3 paraB, the characteristic peaks at 975, 950, 932, 867, 676 and 488 cm À1 , and at 972, 937, 926, 872, 675 and 493 cm À1 , respectively, are attributed to the W O t and W-O-W vibrations in the paratungstate anion, which are in agreement with previously reported data (Table 1; Qu et al, 2012). The slight peak displacements are due to the effects of different coordination modes of paratungstate B.…”

Unconventional Dexter–Silverton Type Manganese Heteropolytungstate [Mn7(MnW12O42(OH)4·8H2O)] Hollow Microsphere: Synthesis, Crystal Structure, Growth Mechanism, and Optical Property Study

“…Thermal behavior of the Mn-HPT phase was studied by TG-DSC under N 2 atmosphere, and the observations are shown in the Figure a. The TG curve shows an initial weight loss of about 4.3% in the temperature range 30–200 °C with an associated endothermic peak which corresponds to the elimination of all (eight) coordinated water molecules (calculated 4.2% for 8 H 2 O molecules) from the lattice. ,− Next, ∼9.2% weight loss has occurred in the temperature range 200–425 °C which is due to the gradual decomposition of the citric acid (into CO 2 and H 2 O) bound with the HPT structure. In the DSC curve, the decomposition starts with a strong exothermic peak at 230 °C, followed by three endothermic peaks at 285, 370, and 430 °C, which agrees with the different decomposition state of citric acid .…”

“…Different characteristic modes of the HPT lattice appeared in the range of 1000−400 cm −1 . 15,24,37,42 All peaks were associated with four different W−O bonds present in each WO 6 octahedron, according to Hook's law (the stronger bonds lead to higher frequency). The peak at 915 cm 2), face shared axial oxygen) bond.…”

“…So far, only few transition metal based HPT structures (1D, 2D, and 3D) have been reported in the literature, ,,− and most of them contain the paradodecatungstate-B, [H 2 W 12 O 42 ] 10– type polyanion. Some researchers have also documented organic–inorganic hybrid structures using this polyanion as a ligand. , In all of these reports, the complex anion was found to have the classic Keggin type structure of either monoclinic (space group: P 2 1 / n ) or triclinic (space group: P 1̅) symmetry and to consist of four corner-sharing tungsten trimeric subunits.…”

Synthesis and characterization of the Anderson–Evans tungstoantimonate [Na5(H2O)18{(HOCH2)2CHNH3}2][SbW6O24]

“…The IR spectrum of SbW 6 (Fig. 3) is characteristic for Anderson-Evans POMs (Liu et al, 2015;Qu et al, 2012). The broad bands in the region between 2300 to 3750 cm À1 represent the vibrations of the -OH groups of H 2 O and the N-H bonds of the amine groups of serinol.…”