Anion Templated Crystal Engineering of Halogen Bonding Tripodal Tris(halopyridinium) Compounds

2020-02-20T05:48:21Z (GMT) by Emer Foyle Nicholas White
In this work four new tripodal tris(halopyridinium) receptors containing potentially halogen
bonding groups were prepared. The ability of the receptors to bind anions in competitive
CD3CN/d6-DMSO was studied using 1H NMR titration experiments, which revealed that the
receptors bind chloride anions more strongly than more basic acetate or other halide ions.
The solid state self–assembly of the tripodal receptors with halide anions was investigated by
X-ray crystallography. The nature of the structures was dependent on the choice of halide
anion, as well as the crystallisation solvent. Halogen bond lengths as short as 80% of the sum
of the van der Waals radii were observed, which is shorter than any halogen bonds involving
halopyridinium receptors in the Cambridge Structural Database.