DFT Study of the Interaction of Cu(II), Zn(II), Sn(II) with Carbohydrates in Aqueous Solution

In the present work, authors studied the interaction between carbohydrates as ligands such as L1: fructose, L2: glucose and L3: sucrose with metal(II) halides such as CuCl2, ZnCl2, SnCl2. Also authors compare the stability of the metal-ligand bond strength. DFT (density functional theory) was utilized using the B3LYP functional and the 6-31G(d) basis set. This level of calculation was used for optimization of geometry of ligands and exploring electronic properties such as ionization potential (I), electron affinity (A), chemical potential (μ), hardness (η), band gap (HOMO (highest occupied molecular orbital)-LUMO (lowest unoccupied molecular orbital)). The local reactivity was analyzed by the fukui function indices and the indices local of nucleophilicity in order to predict the sites of attack of carbohydrates. In addition, the strength of interaction has been evaluated by energy lowering and charge transfer using DFT at the B3LYP level employing the basis set Lan2DZ. As a result, the sequence of high stability of metal-ligand bond for ligands is in the following order; sucrose > glucose > fructose. Furthermore, the sequence of high stability for metal halides is in the following order, CuCl2 > SnCl2 > ZnCl2. We advise person who carries a dental amalgam do not exceed the consommation of monosaccharides, because their complexes are not sufficiently stable and hence these ions are not ejected easily outside the human body.