DFT Study of Benzamide Coordination with Zinc (II)

Benzamide (C6H5CONH2) is the first representative of the aromatic acid amides. Its molecule contains an amide group. Amide group is the main structural unit of polyamides, peptides and proteins. This functional group plays a special role in very important vital processes. The aromatic acid amides and their derivatives, as well as other amides, are widely used in medicine as physiologically active substances, as the central nervous system stimulants, and as antituberculosis substances. The coordination of these compounds profoundly modifies the physiological properties of metals and those of ligands in the direction of the overall positive modification of these properties. Benzamide, like other amides, contains two donor atoms (nitrogen and oxygen). It is important to know the potential donor that takes part in the coordination bond. To answer these questions we referred to quantum methods. We performed the calculations by the DFT/B3LYP method in the Lanl2dz basis set using the Gaussian 98W program on the computer HPL1908w. First we studied the benzamide molecule and then we simulated its complexation with ZnCl2. From the analysis of the results which take into account the atomic charges, atom electrostatic potentials and other energy parameters of the studied systems, it appears that the coordination bond of benzene with zinc takes place via the oxygen atom; and the complex obtained was the dichloro di benzamide zinc (II) complex which formula was [Zn (C6H5CONH2)2Cl2].