Investigation of Non-Covalent Interactions of Copper (II) Complexes with Small Biomolecules

In this chapter, the influence of non-covalent interactions on the complexes formed by the various biomolecules (mesalazine, para-aminosalicylic acid, acetaminophen, psoralen, and methyl salicylate) with the Cu2+ cation is investigated using the density functional theory (DFT) method. Since the interactions involving aromatic rings are crucial binding forces in chemical systems, this is exciting research trying to understand and control the effect of non-covalent interactions responsible for complicated functions in nature. Herein, the calculations are performed in the gas phase and water solvent. The results show that the absolute amounts of energy are reduced by going from the gas phase to the solution. The topological properties of the electron density and the values of charge transfer are evaluated by the Bader theory of atoms in molecules (AIM) and the natural bond orbital (NBO) analysis, respectively. These results are useful for understanding the role of the drug-receptor interactions in the complexes. The electronic descriptors are also important factors in forming a charge-transfer complex between cation and biological target. The results of this study that are ubiquitous in biological systems may be useful for the design and synthesis of a variety of supramolecular complexes with the desired properties