A DFT Study on Adsorption of Alanine on Pristine, Functionalized and Boron and/or Nitrogen Doped Functionalized C60 Fullerenes

In this study, the adsorption of alanine on pristine, functionalized, and boron and/or nitrogen doped functionalized C60 fullerenes was studied by theoretical methods. For this purpose, the structures of alanine, C60 fullerenes derivatives and complexes (C60-alanine) were optimized by using M062X/6-31G* level of theory. Then, it was calculated the adsorption energies, global DFT reactivity indices, the atomic charges and the global electron density transfer (GEDT). The results showed that the maximum adsorption energy occurs for the adsorption of alanine on C60H-OH derivative in both gaseous and aqueous phases. In addition, the doping three nitrogen/boron atoms with the functionalized carbon atom in C60H-OH increases the adsorption energy significantly. The results were confirmed by global DFT reactivity indices such as chemical potential and electrophilicity indices. In addition, analysis of the GEDT values showed that the charge transfer occurs from alanine toward C60H-OH fullerene in both phases upon adsorption. AIM results indicated that the interaction between alanine and C60H-OH in both gaseous and aqueous phases is non-covalent and hydrogen interaction.