Polymeric metal complexes macroligands

Lanthanide complexes with polymeric ligands combine the fevorable optical properties of lanthanide metals with die processing advantages of polymer films. Polymeric metal complexes (PMCs), comprised of macroligands coordinated to metal ions, provide a unique platform offering a wide range of possibilities for... 

Figure 1. Schematic representation of a polymeric metal complex (left) and two stage degradation mechanism, at the metal center via macroligand dissociation (center) and along the polymer backbone (right).

Polymeric metal complexes with polyester macroligands have been generated by initiation from hydroxyl functionalized ligand and metal complex reagents. Ligand initiators lead to macroligands which can be combined with metal precursors in coordination reactions to produce PMCs (51). Metalloinitiators, on the other hand, produce PMCs directly (2). 

Macromolecular metal complexes can be classified into three main categories, taking into consideration the manner of binding of a metal compound to suitable macroligands [33] (Fig. 1). Type 1 metal complexes are those with the metal ion or metal chelate at a macromolecular chain, network, or surface. One possible approach to synthesize such polymers is using the polymerization of vinyl-substituted metal complexes. 

Monomers of metal complexes/chelates suitable for polymerizations, and also polycondensations or polyaddition reactions, can be employed successfully for the preparation of metal containing polymers. In most cases polymerizations are carried out in the presence of a comonomer to obtain polymers with sufficient solubility. For polymerizations either a vinyl group containing ligand is polymerized followed by introduction of a metal ion in the macroligand, or the vinyl group containing metal complex/chelate is directly converted into the MMC. In some cases when chain transfer due to a transition... 

Complex formation takes place in an organic solvent or in a water/monomer mixture by reaction of the macroligand with a metal compound (e.g. a Cu(I)-ha-lide). It is supposed that the conditions in the reaction mixture are comparable to those in conventional emulsion polymerization, where monomer droplets stabilized by surfactant molecules coexist with monomer swollen micelles [64]. Reaction sites are presumably the hydrophobic core of the micelles and the monomer droplets as well. Initial results of the micellar-catalyzed ATRP of methyl methacry-... 

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