Quantum chemical analysis of hydrogen bonding in pyrrolidone dimers and pyrrolidone–water complexes

•The resulting O-H…O hydrogen bonds can be attributed to the bonds of medium strength.•The weaker O… H-C interaction is about 10–25% of the classic H-bond interaction energy according to QTAIM data.•The many-body effects play an important role in the formation of bonds, which can both strengthen or weaken the interactions.•Stronger bonds correspond to higher polarization of the corresponding atoms.•Different functionals give different parameters, but in most cases, there is good agreement of relative values. The structure of pyrrolidone dimers and hydrogen-bonded complexes of pyrrolidone with water molecules (1–3 molecules in complex) was studied by quantum chemical method on the basis of density functional theory (DFT) using three-parameter hybrid Becky-Lee-Yang-Parr functional and gradient-corrected correlation functional of Perdew, Burke and Ernzerhof (PBE) with D3 version of Grimme dispersion correction, Austin-Frisch-Petersson functional with dispersion correction (APFD) and augmented correlation-consistent polarized valence-only triple-zeta (aug-CC-pVTZ) basis set. The geometrical parameters of hydrogen bonds, binding energies, atomic charges based on Atomic Polar Tensors (APT) and vibrational frequencies were calculated and Natural Bond Orbital (NBO) and quantum theory of atoms in molecules (QTAIM) methods were used. The analysis was carried out for classic H-bonds and C-H…O. The calculations also were made taking into consideration the water medium with the integral equation formalism polarizable continuum model (IEFPCM).