The effects of charge density distributions of metal ions on single water molecule dissociation of [M(H₂O)₆]³⁺ systems

Abstract

Some effects of cationic charge density distribution on single water molecule dissociation of [M(H 2 O) 6 ] 3+ clusters with M=Cr, Mn, Fe, Co, and Ni have been investigated using first-principles study. The molecular structures, molecular binding energies, hydration enthalpies, cation and water molecules orbitals, infrared vibrational frequencies, and potential energy surfaces/curves had been computed to fulfill the purpose of research. Our investigation results have revealed that the hollow shape of charge density of central Cr(III) makes the Cr-O bonds rigid as indicated by a higher activation energy for releasing one water molecule from [Cr(H 2 O) 6 ] 3+ . The isotropic charge density of Fe(III) affects in lowering water rotational rigidities which is responsible for augmenting the activation energy, while the cones-shape charge density of Ni(III) weakens the ion-dipole interactions by increasing interactions between nearest neighbour water molecules.