Coordination Polymers of Cucurbit[n]urils with Metal Ions - Supramolecular Assemblies of Cucurbit[n]urils with Metal Ions - page 65

Fig. 3.26 X-ray crystal structures of the 3D framework in which a the UO 2cluster /C9 dicarboxy-
late layers are bridged by Q[6] molecules; and b the UO 2cluster /Q[6] 1D coordination polymer is
bridged by C9 dicarboxylate ligands
with the 2D or ribbon-like topologies most common among uranyl organic
species, which opens perspectives for the design of hybrid layered materials.
Again, a Q[6]/Cd 2 + -based 3D framework may readily be obtained by mix-
ing KCl, CdCl 2 , and Q[6] in a HCl solution [ 47 ]. Although no K + ions seem to
be present in the solid compound, they appear to act as structure directing agents,
resulting in the formation 3D Q[6]/Cd 2 + -based 3D framework. The X-ray crystal
structure shows the coordination feature of Cd 2 + cations with Q[6] (Fig. 3.27 a, b).
A Q[6] molecule appears to coordinate with six Cd 2 + cations to form Cd 2 ( ʼ -
Cl) 2 Cl 2 (H 2 O) 3 complexes (Fig. 3.27 c). Each Cd 2 + cation coordinates to six atoms
(with 50 % occupancy), one portal carbonyl oxygen (O3), three water molecules
(O1W, O7W, and O9W), and two chloride anions (2Cl1), which are shared by