title: Halogen and Hydrogen Bonding between (N-Halogeno)-succinimides and Pyridine Derivatives in Solution, the Solid State and In Silico.
abstract: A study of strong halogen bonding within three series of halogen-bonded complexes, derived from seven para-substituted pyridine derivatives and three N-halosuccinimides (iodo, bromo and chloro), has been undertaken with the aid of single-crystal diffraction, solution complexation and computational methods. The halogen bond was compared with the hydrogen bond in an equivalent series based on succinimide. The halogen-bond energies are in the range -60 to -20 kJ mol-1and change regularly with pyridine basicity and the Lewis acidity of the halogen. The halogen-bond energies correlate linearly with the product of charges on the contact atoms, which indicates a predominantly electrostatic interaction. The binding enthalpies in solution are around 19 kJ mol-1less negative due to solvation effects. The optimised geometries of the complexes in the gas phase are comparable to those of the solid-state structures, and the effects of the supramolecular surroundings in the latter are discussed. The bond energies for the hydrogen-bonded series are intermediate between the halogen-bond energies of iodine and bromine, although there are specific differences in the geometries of the halogen- and hydrogen-bonded complexes.
authors.affiliation: Department of Chemistry, Faculty of Science, University of Zagreb, Horvatovac 102a, Zagreb, Croatia.
authors.forename: Vladimir
authors.identifier: http://orcid.org/0000-0002-4383-5898
authors.initials: V
authors.lastname: Stilinović
authors.affiliation: Department of Chemistry, Faculty of Science, University of Zagreb, Horvatovac 102a, Zagreb, Croatia.
authors.forename: Gordan
authors.initials: G
authors.lastname: Horvat
authors.affiliation: Department of Chemistry, Faculty of Science, University of Zagreb, Horvatovac 102a, Zagreb, Croatia.
authors.forename: Tomica
authors.initials: T
authors.lastname: Hrenar
authors.affiliation: Department of Chemistry, Faculty of Science, University of Zagreb, Horvatovac 102a, Zagreb, Croatia.
authors.forename: Vinko
authors.initials: V
authors.lastname: Nemec
authors.affiliation: Department of Chemistry, Faculty of Science, University of Zagreb, Horvatovac 102a, Zagreb, Croatia.
authors.forename: Dominik
authors.initials: D
authors.lastname: Cinčić
keywords: Lewis acids; crystal engineering; halogen bonds; hydrogen bonds; supramolecular chemistry