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

Abstract

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 (NH⋯S, CH⋯S) and π–S bonding (N⋯S, C⋯S) 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.