A CdSO4-like 3-D framework constructed from monosodium substituted Keggin arsenotungstates and copper(II)-ethylenediamine complexes

Combined use of Synchrotron Radiation Based Micro-X-ray Fluorescence, Micro-X-ray Diffraction, Micro-X-ray Absorption Near-Edge, and Micro-Fourier Transform Infrared Spectroscopies for Revealing an Alternative Degradation Pathway of the Pigment Cadmium Yellow in a Painting by Van Gogh

“…It is interesting that the maximum of this band situates itself between those of pure calcium oxalate (1320 cm –1 ) and pure cadmium oxalate (1314 cm –1 ) and might therefore be corresponding to the presence of a mixture of several oxalates, a finding that is corroborated by the aforementioned observation of Ba, Sr, and Hg in the oxalate layer. The characteristically shaped band from 1000 to 1200 cm –1 points to the presence of sulfates, while the band from 1500 to 1700 cm –1 is likely to be linked to both oxalates and sulfates . The peak between 1400 and 1500 cm –1 is consistent with the presence of carbonates (ν3 from 1300 to 1500 cm –1 ), while the double peak near 1710–1730 cm –1 may be associated with fatty acid esters.…”

“…The characteristically shaped band from 1000 to 1200 cm −1 points to the presence of sulfates, while the band from 1500 to 1700 cm −1 is likely to be linked to both oxalates and sulfates. 31 The peak between 1400 and 1500 cm −1 is consistent with the presence of carbonates (ν3 from 1300 to 1500 cm −1 ), while the double peak near 1710−1730 cm −1 may be associated with fatty acid esters. Accordingly, the maps shown in Figure 4 were obtained by summing the absorbance in the bands 1000− 1233 cm −1 (sulfates) and 1283−1347 cm −1 (oxalates).…”

An organic–inorganic hybrid dimeric arsenotungstate [enH2]4{[Cu(en)2][(A-β-H2AsW9O34)Cu(en)2]2}·8H2O established by two trivacant Keggin [A-β-AsW9O34]9− fragments in the opposite orientation

“…Currently, we are changing the usage amount of ErCl 3 or making use of other Ln cations in place of the Er III cation to synthesize new 3d-4f heterometallic AT analogs. In addition, we have already developed the system including Na 8 [27]. Additionally, in the formation of 1, the precursor [A-α-AsW 9 O 34 ] 9− was isomerized to the [A-β-AsW 9 O 34 ] 9− unit, which is very uncommon under hydrothermal conditions.…”