Halogen Bonding in Crystal Engineering - Halogen Bonding: Fundamentals and Applications - page 124

Fig. 11 Ladder-type architecture formed by self-assembly of a tridentate module (I - ) with
a bidentate module (1,4-DITFB)
with layers formed by the halogen-bonded supramolecular anions [83, 128,
155, 156, 178, 189, 193] (Fig. 12).
The layer thickness usually depends on the compounding module's size
and an accurate metric engineering can be done according to which the
length of starting module determines the thickness of the layer. This holds for
self-assembled architectures wherein the XB acceptor is both an anionic [189]
(Fig. 13) and a neutral tecton [168].
3.3
3D Architectures
When one, or both, of the interactive modules are tetradentate, bi- or
tridimensional (3D) architectures can be formed. An example of 2D archi-
tecture is the (4,4) network present in the complex diiodoacetylene/Ph 4 P +
Cl - (and the analogous complexes formed by bromide or iodide an-
ions) [194] as well as in the complex 1,6-diiodoperfluorohexane/tetrakis(4-
pyridyl)pentaerythritol [195]. In all these complexes, the XB acceptor works
as the tetradentate tecton sitting at the node of the network and the
XB donor works as the linear bidentate module that spaces the nodes.