Nature of weak inter- and intramolecular interactions in crystals. 1. The F...O and F...H contacts in the crystal of 2-trifluoroacetyl-5-trifluoromethylpyrrole

The topological analysis of the electron density distribution in the crystal of 2-trifluoroacetyl-5-trifluoromethylpyrrole revealed that the F...H and F...O intermolecular contacts correspond to attractive interactions. The energies of these interactions were estimated from the experimental data and it was shown that these contacts are similar to the C—H...O contacts. Analysis of the deformation electron density revealed that the F...O contacts correspond to transfer of the lone electron pair of a fluorine atom to the antibonding -orbital of the C=O bond.