Influence of noncovalent intramolecular and host-guest interactions on imatinib binding to MoS2 sheets: a PXRD/DFT study

The structural and energetic aspects of bonding interactions between a molecule of the antileukemic drug imatinib and a sheet of nanodispersed molybdenum disulfide noted for its excellent photothermal and antimicrobial efficacy have been studied by powder X-ray diffraction (PXRD), density functional theory (DFT) calculations and quantum theory of atoms in molecules (QTAIM) analysis. In the built structural models with imatinib interlaying MoS2 sheets or situated on the surface of a single sheet, a set of noncovalent hydrogen bonding (NHMIDLINE HORIZONTAL ELLIPSISS, CHMIDLINE HORIZONTAL ELLIPSISS) and pi-S bonding (NMIDLINE HORIZONTAL ELLIPSISS, CMIDLINE HORIZONTAL ELLIPSISS) interactions established between the S atoms and imatinib groups has been identified. The effect of these interactions on the conformational preference of imatinib, however, is outweighed by the strong intramolecular bonding within this molecule, preventing adjustment of its structure for closer binding to MoS2. The modest affinity of imatinib molecules to the sulfide sheets should be advantageous for drug release from the sulfide surface in the case of MoS2 functioning as a carrying agent. The data obtained in the study are hoped to be useful for designing novel biologically active systems containing MoS2 sheets.

Automated summary

The study examined the bonding interactions between the antileukemic drug imatinib and nanodispersed molybdenum disulfide, and identified noncovalent hydrogen bonding and pi-S bonding interactions between the S atoms and imatinib groups. These interactions were found to be outweighed by the strong intramolecular bonding within the imatinib molecule, limiting its ability to bind more closely to MoS2. The data could be useful for designing biologically active systems containing MoS2 sheets.