Computational study of chemical properties of Captopril drug and the connected form to Fullerene (C60) as a medicine nano carrier

In this research at the first, captopril drug (CA) and its fullerene connected form (FCA) were optimized. Natural Bond Orbital (NBO) calculations for these compounds were carried out at the B3LYP/6-31G quantum chemistry level, in the gas phase and the liquid phase. These calculations can be performed at different accuracy levels depending on the aim of the theoretical study [1]. For instance, Density Functional Theory (DFT) can be used to calculate an accurate electronic structure, HOMO and LUMO energies, Mulliken charge of atoms, energetic_orbital levels, chemical hardness, chemical potential and electrophilicity of systems, and finally chemical, physical, biological, pharmacological and industrial of fullerene and fullerene derivatives [4–7]. Theoretical calculations such as NBO are very important to understand the pathways of electron transfer in assemblies. Consequently, the obtained results showed that energy orbital levels decreased considerably by linking structure of Captopril to structure of fullerene C60. In the study some other characteristics such as chemical potential, chemical hardness, electrophilicity in these structures; it was found that they changed considerably. These changes show dependency of the results, on power of electron affinity of C60. In another part, the valence electrons populations for carbons, nitrogen, oxygens and hydrogens atoms in similar position for FCA and CA were compared. Finally the data were compared and discussed.