Charge density and electrostatic potential analysesin paracetamol

摘要

The electron density of monoclinic paracetamol was derivedfrom high-resolution X-ray diffraction at 100 K. The Hansen-Coppens multipole model was used to refine the experimentalelectron density. The topologies of the electron density andthe electrostatic potential were carefully analyzed. Numericaland analytical procedures were used to derive the chargesintegrated over the atomic basins. The highest chargemagnitude (-1.2 e) was found for the N atom of theparacetamol molecule, which is in agreement with theobserved nucleophilic attack occurring in the biologicalmedia. The electric field generated by the paracetamolmolecule was used to calculate the atomic charges using thedivergence theorem. This was simultaneously applied toestimate the total electrostatic force exerted on each atomof the molecule by using the Maxwell stress tensor. Theinteraction electrostatic energy of dimers of paracetamol inthe crystal lattice was also estimated.