STUDY OF VANADATE UNITS USING DENSITY FUNCTIONAL THEORY: ELECTRONIC PROPERTIES AND REACTIVITY

The vanadate units have been theoretically investigated through density functional theory calculations. The global reactivity indices have been optimized. The obtained results revealed that the (Q(0)) [VO4](3-) unit shows an electron-donor character, while the units Q(1), Q(2), and Q(3) units are evidenced to exhibit an electron-acceptor feature. The transition from one unit to another is found to be accompanied by an increase in the number of bridging oxygen atoms, in accordance with the highlighted changes in Mulliken charges. Moreover, the analysis of the optimized electrostatic potential surfaces indicated a higher likelihood of nucleophilic attacks on the vanadium atoms. Predictions for infrared and Raman spectra were also conducted, revealing changes in symmetric and asymmetric vibrational bands as the number of bridging oxygen atoms varied. Additionally, Fukui indices were employed to identify the preferred sites for the electrophilic attack within the (Q(0)) [VO4](3-) unit on the Q(1), Q(2), and Q(3) vanadate units.