Hydrogen-bond directionality and symmetry in [C(O)NH](N)₂P(O)-based structures: a comparison between X-ray crystallography data and neutron-normalized values, and evaluation of reliability

Abstract

For [C(O)NH](N)2P(O)-based structures, the magnitude of the differences in the N—H...O, H...O=P and H...O=C angles has been evaluated when the N—H bond lengths, determined by X-ray diffraction, were compared to the neutron normalized values and the maximum percentage difference was obtained, i.e. about 3% for the angle even if the N—H bond lengths have a difference of about 30% (0.7 Å for the X-ray and 1.03 Å for the neutron-normalized value). The symmetries of the crystals are discussed with respect to the symmetry of the molecules, as well as to the symmetry of hydrogen-bonded motifs, and the role of the most directional hydrogen bond in raising the probability of obtaining centrosymmetric crystal structures is investigated. The work was performed by considering nine new X-ray crystal structures and 204 analogous structures retrieved from the Cambridge Structural Database.

Investigation of crystal structures, energetics and isostructurality in halogen-substituted phosphoramidates

“…[CSD refcodes LEQRIK/LEQRIK01 (Gholivand et al, 2013) and HOBSID/HOBSID01 (Hasija & Chopra, 2019)]. On exploring more, derivatives of phosphoric acid have been unraveled, where the study encompasses the detailed investigation of the crystalline arrangement via the presence of different intermolecular interactions (DuPlessis et al, 1982;Tarahhomi et al, 2012Tarahhomi et al, , 2013Hamzehee et al, 2016;Farkhani et al, 2018;Taherzadeh et al, 2021).…”