Zinc coordination polymers, self-assembled

Functional Self-Assembled Zinc(II) Coordination Polymers... 

In 2003, we first used self-assembled zinc(II) terpyridine polymers in the fabrication of PLEDs.22 We synthesized a series of monomers containing two terpyridine as chelating units, which are at opposite ends and separated by a spacer group (R) (Fig. 5). The self-assembled zinc(II) coordination polymers were easily prepared by the addition of Zn(OAc)2 into solution of monomers. The product yields were up to 80%, and the inherent viscosities of the polymers were in the range of 0.48 to 1.21 dL/g, as determined using an Ubbelohde viscometer in NMP at 30 0.1 °C. 

Zinc(II) phthalocyanine 55 bearing two pyridyl substituents is also capable of forming a self-assembled array [56], This compound forms intermolecular zinc-nitrogen coordinated species in solution and self-assembles to form a coordination polymer in the solid state. As shown in the crystal structure revealed by singlecrystal X-ray diffraction analysis, the compound self-assembles in an edge-to-face manner forming a zig-zag polymer in the solid state (Fig. 3). 

Supramolecular entities are prepared either by designed or self-assembly, or by the breakdown of larger species - the so-called bottom-up and top-down approaches respectively. Most supramolecular zinc compounds have been obtained by self-assembly methods, often operating in a rather hit-and-miss way. However, controlled cleavage of coordination polymers should prove a useful route to predesigned supramolecular assemblies. An example of this approach is provided by the... 

An example of a three-dimensional penetrating network is the solvated [(ZnCl2)3(35)2] 56 [139], The triazine molecules are part of threefold connecting knots (Fig. 7-17). The zinc atoms have a nearly tetrahedral coordination geometry with two N atoms of 35 and two chlorine ligands. A distorted network is obtained. The self-assembly of CUSO4 in water and l,3-bis(4-pyridyl)propane in ethanol results in 57 which presents a three-dimensional architecture sustained by two different types of coordination polymer one-dimensional ribbons of rings and two-dimensional layers (Fig. 7-18) [138]. 

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