Theoretical insights into phosphate chains: Density functional theory study and Zinc ion insertion reaction

The present research delves into a theoretical examination of phosphate chains using the density functional theory method with the RB3LYP/6-311G model. The geometry of the studied chains was optimized and their atomic charge densities were evaluated. Various parameters, such as HOMO and LUMO energies, energy difference (ΔE), chemical hardness, chemical potential, softness, and global electrophilicity index were thoroughly investigated. Moreover, vibrational frequencies were explored, highlighting both symmetric and asymmetric vibrations in the chains based on the computed IR and Raman spectra. Subsequently, an investigation into the Zinc ion insertion reaction in the studied phosphate chains was carried out. Several parameters were calculated to determine the electrophilic/nucleophilic character of these two constituents. The outcomes revealed that the phosphate chains display nucleophilic behavior and tend to release electrons, while the Zinc ion exhibits electrophilic tendencies and retains electrons. Notably, electron transfer occurs from the chains to the Zinc ion, with the chains acting as electron donors and the Zinc ion as an electron acceptor. The smaller overall electrophilicity gap between chain III and Zn2+ indicates the weak polar character of this reaction. Furthermore, favorable nucleophilic sites for the attack of the Zinc ion (Zn2+) on chain III were identified using the FUKUI indexes.