Quantum chemical calculations of the molecular structures of hybrid amino acid derivatives of fullerene C60

The stereoselectivity of the formation of hybrid amino acid derivatives of fullerene (AADF) C60 was studied. The energies of the model addition reactions C60 + n C2H6 ⇆ Men-C60-Men(1) and C60 + n EtNC4H7Me ⇆ Etn-C60-(NC4H7Me)n (2) (n = 1–3) were calculated by the DFT method B3LYP/6-31G*. The most stable products of reaction (1) are hexamethylated fullerene derivatives in which five Me groups are arranged in the form of a regular pentagon. Among the AADF obtained by reaction (2), 1,4-disubstituted fullerene isomers are most stable. The molecular structures of such isomers were calculated for six biologically active hybrid AADF; the solvent contact areas of these molecules were evaluated.