Fluoride ligands exhibit marked departures from the hydrogen bond acceptor behavior of their heavier halogen congeners

Abstract

Much shorter hydrogen bonds with unexpected directional properties are formed by fluoride ligands in comparison to their heavier halogen congeners (X=Cl, Br, I). Abinitio calculations elucidate the underlying electronic origin of this geometric behavior. The viability of hydrogen bonding is clearly established for all donor–acceptor combinations, D–H···X–M (D=C, N, O; X=F, Cl, Br, I).