Bond orders for intermolecular interactions in crystals: charge transfer, ionicity and the effect on intramolecular bonds.

ABSTRACT: The question of whether intermolecular interactions in crystals originate from localized atom⋯atom interactions or as a result of holistic molecule⋯molecule close packing is a matter of continuing debate. In this context, the newly introduced Roby-Gould bond indices are reported for intermolecular 'σ-hole' interactions, such as halogen bonding and chalcogen bonding, and compared with those for hydrogen bonds. A series of 97 crystal systems exhibiting these interaction motifs obtained from the Cambridge Structural Database (CSD) has been analysed. In contrast with conventional bond-order estimations, the new method separately estimates the ionic and covalent bond indices for atom⋯atom and molecule⋯molecule bond orders, which shed light on the nature of these interactions. A consistent trend

SUBMITTER: Alhameedi K 

PROVIDER: S-EPMC6126646 | biostudies-literature | 2018 Sep

REPOSITORIES: biostudies-literature