Non-covalent interactions of cysteine onto C60, C59Si, and C59Ge: a DFT study

Abstract

The study of intermolecular interactions is of great importance. This study attempted to quantitatively examine the interactions between Cysteine (C3H7NO2S) and fullerene nanocages, C60, in a vacuum. As the frequent introduction of elements as impurities into the structure of nanomaterials can increase the intensity of intermolecular interactions, nanocages doped with silicon and germanium have also been studied as adsorbents C59Si and C59Ge. Quantum mechanical studies of such systems are possible in the density functional theory (DFT) framework. For this purpose, various functionals, such as B3LYP-D3, ωB97XD, and M062X, have been used. One of the most suitable basis functionals for the systems studied in this research is 6-311G (d), which has been used in both optimization calculations and calculations related to wave function analyses. The main part of this work is the study of various analyses that reveal the nature of the intermolecular interactions between the two components introduced above. The results of conceptual DFT, natural bond orbital, non-covalent interactions, and quantum theory of atoms in molecules were consistent and favored physical adsorption in all systems. Germanium had more adsorption energy than other dopants. The HOMO-LUMO energy gaps were as follows: C60: 5.996, C59Si: 5.309, and C59Ge: 5.188 eV at B3LYP-D3/6-311G (d) model chemistry. The adsorption sensitivity increased when an amino acid molecule interacted with doped C60, and this capability could be used to design a nanocarrier to detect Cysteine amino acids.

Modeling of magnesium-decorated graphene quantum dot nanostructure for trapping AsH3, PH3and NH3gases

“…and both the ∇ 2 ρ ( r ) and H ( r ) values are positive for all interactions, which indicates the dominance of non-covalent forces between the interacting systems. 76 Furthermore, calculating the values of the ratio − G ( r )/V( r ) gives further insight into the nature of the interactions. 77 As shown in Table 4 , the − G ( r )/ V ( r ) values of >1 for all studied interactions confirm the non-covalent nature of the interactions.…”

Therapeutic Delivery Potential of Covalent Organic Framework (COF): Intuition from Theoretical Calculations

“…Gaussian 16 [28] software was utilized to optimize the systems within the scope of Kohn‐Sham (K‐S) DFT computations. As different orientations were recovered following optimizing the COF with drug molecules (Acetaminophen, Clodronic Acid, Hydroxyurea, Mercaptoporine, Thiotepa, Tioguanine, and Arsenic trioxide as shown in Figure 1) at ωB97XD/def2svp level of theory [29] . The said method was chosen based on its wide range of applications in main group chemistry, transition metal chemistry, molecular structure prediction, bond energies, atomic excitation energies, isomerization of complex molecules, and is renowned for its high precision in non‐covalent interactions and thermochemistry of these types of drug delivery systems and is highly involved in dispersion correction investigations.…”