Covalent and ionic
bonds represent two fundamental forms
of bonding
between atoms. In contrast to bonds with significant covalent character,
ionic bonds are of limited use for the spatial structuring of matter
because of the lack of directionality of the electric field around
simple ions. We describe a predictable directional orientation of
ionic bonds that contain concave nonpolar shields around the charged
sites. Such directional ionic bonds offer an alternative to hydrogen
bonds and other directional noncovalent interactions for the structuring
of organic molecules and materials.