Complexes of a bio-molecule and a C60 cage

First-principles vdW-DF investigation on the interaction between the oxazepam molecule and C₆₀ fullerene

The interaction between oxazepam and C₆₀ fullerene was explored using first-principles vdW-DF calculations. It was found that oxazepam binds weakly to the fullerene cage via its carbonyl group. The binding of oxazepam to C₆₀ is affected drastically by nonlocal dispersion interactions, while vdW forces affect the corresponding geometries only a little. Furthermore, aqueous solution affects the geometries of the oxazepam approaching to fullerene slightly, while oxazepam binds slightly farther away from the nanocage. The results presented provide evidence for the applicability of the vdW-DF method and serve as a practical benchmark for the investigation of host-guest interactions in biological systems.

Molecular structure, electronic property and vibrational spectroscopy of C24-glycine and Gd@C24-glycine complexes

Structure, electronic property and vibrational spectroscopy of C(24)-glycine and Gd@C(24)-glycine were systematically explored using the hybrid DFT-B3LYP functional. The interaction between empty C(24) cage and the smallest amino acid (glycine) was also investigated. It was found that the glycine molecule is energetically favorable to interact with the Mid-site on the C(24) cage through the amino nitrogen active site, rather than Top-site. The endohedral Gd atom increases the volume of the cage by around 6.7-9.8%. Analysis of frontier molecular orbitals reveals that the Gd@C(24)-glycine has the low-kinetic stability, being consistent with its thermodynamic property reflected by dissociation energy. We also see that the VIE and VEA of empty C(24) cage are slightly affected by absorbed glycine and endohedral Gd atom. Additionally, the assignments of simulated IR spectra are explored. The work may provide a theoretical reference for further application related structurally to potential antitumour activity.