Topologic Features of Three Structures Based on I???Base Halogen Bonding
Acta Crystallogr. 2005, A61, C363
T. Pilati, P. Metrangolo, D. Proserpio, G. Resnati
Keywords: topology, crystal engineering, halogen bonding
Keywords: topology, crystal engineering, halogen bonding
ABSTRACT
The halogen bonding, that is the n to sigma* electron donation from Lewis bases to halogen atoms (Lewis acids) is an interaction that has attracted an increasing attention, especially in haloperfluorocarbons were the heavy halogen atom (I, Br) is highly polarized1. We have recently studied the three component structure of the cryptate K.2.2.2 with KI and 1,8-diiodo-perfluorooctane showing a very unusual borromean assembly of the superanion2. We present here other three halogen-bonded supra-molecular arrays showing unusual topologic features: the assembly of tetra(4-pyridyl)pentaerythritol . 1,4-diiodooctafluorobutane 1, tetra(4-pyridyl)pentaerythritol . 1,8-diiodohexadecafluorooctane 2, and tetra(4-pyridyl)pentaerythritol . tetra(4- iodo-tetrafluorophenyl)pentaerythritol 3. The three structures present macrocyclic interpenetrate assembly. 1, 2, 3 show 2D 5-fold 44 layers, 8-fold diamondoid class Ia, 10-fold diamondoid class IIIa topologies, respectively.