The study of thermal-induced 2D-COS IR on polyoxomolybdenum (polyoxotungstic)

Two-dimensional correlation infrared spectroscopy (2D-COS) were employed to investigate temperature-dependent spectral variations [(PO4)2Mo5O15]6−, β-[Mo8O26]4−, [PMo12O40]3−, [P2W18O60]6− cluster anions. Two-dimensional correlation spectra in 800–1000 cm−1 region provides information about the variations of the terminal MoO bonds in the polyoxomolybdenum (or Polyoxotungstic) cluster anions. In 600–800 cm−1 region, it reveals the information about the variations of the bridging MoOMo bonds in the cluster anions. The results indicated that the intensity change of the terminal MoO bonds are more sensitive than the bridging Mo–O–Mo bands to the temperature variation. Furthermore, from [(PO4)2Mo5O15]6−, β-[Mo8O26] to [PMo12O40]3−, with the cluster anions becoming larger, the 2D-IR spectra showed the bridging Mo–O–Mo bonds in the cluster anions were becoming more sensitive to temperature variation.