Metal complexes cofacial stacked

Characterization of conjugated metallopolymers can be difficult. When the metals are paramagnetic, very broad NMR spectra are obtained. Also, many metal complexes, particularly porphyrins and phthalocyanines, aggregate in solution. This leads to broad NMR spectra and can lower solubility. Some researchers have used bulky substituents to disrupt cofacial stacking, but this can add several synthetic steps to the polymer preparation. It is often difficult to obtain clear, unequivocal characterization of the structures of metallopolymers. 

A great variety of possibilities are available when a metal is part of a linear or crosslinked macromolecule (Section 1.2.1, Fig. 7-1). One possibility is the covalent incorporation of a metal into a homochain (metal-metal connections) or a heterochain (metal-heteroatom connections). Coordinative bonds between a metal ion and another coordinating donor group can lead to linear chains or to supramolecular organizations when coordination polymers are formed. n-Bonds between rt-rich aromatic compounds and metal ions can result in polymeric metallocenes. Covalent and coordinative bonds are realized in cofacially stacked metal complexes. In addition, dendrimers containing the interaction of metals and another group in different bonds are treated in this chapter. 

Type III The metal is part of a polymer chain or network. This type considers homochain or heterochain polymers with covalent bonds to the metal, coordinative bonds between metal ions and a polyfunctional ligand (coordination polymers), Ti-complexes in the main chain with a metal, cofacially stacked polymer metal complexes and different types (polycatenanes, polyrotaxanes, dendrimers with metals) (Figure 3). 

Cofacial phthalocyanine polymers are materials in which file macrocyclic rings are stacked in a shish-kebab maimer with the metals as part of file polymeric chain. " These polymers often display excellent thermal and chemical stability and are electrically conducting, sometimes even in the absence of a doping agent. Scheme 9 shows the synthesis of polymer 41 by reaction of the ferrous phthalocyanine complex (39) with pyrazine (40). ... 

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