Experimental electron density study of the supramolecular aggregation between 4,4′-dipyridyl-N,N′-dioxide and 1,4-diiodotetrafluorobenzene at 90 K

The electron density of the halogen-bonded complex of 4,4'-dipyridyl-N,N'-dioxide (bpNO) with 1,4-diiodotetrafluorobenzene (F(4)dIb) at 90 K has been determined by X-ray diffraction and analysed. The nature of the I.O intermolecular bond connecting the bpNO and F(4)dIb molecules into one-dimensional infinite chains, as well as the other non-covalent interactions present in the crystal, such as C-H...O, C-H...F and C-H...I hydrogen bonds and C...C, C...N, C...I and F...F interactions, have been investigated. The integration of electron density over the atomic basins reveals the electrostatic nature of the I...O halogen bond, which is very similar to a previously analysed I...N halogen bond.