Coordination polymers traditional

The second consideration when attempting to prepare crystals of coordination polymers is the crystallisation condition used. As stated above, recrystallisation approaches are not usually appropriate for the growth of coordination polymer systems, due to solubility reasons. Another method of crystallisation often used for molecular systems, that of vapor diffusion of an anti-solvent into solutions of the product, is also rarely possible for coordination polymer systems. As with traditional recrystallisation this is due to the insolubility of the product material and consequently to the difficulty of obtaining solutions of either the coordination polymer or its constituent parts. 

Structure-based nomenclature can also be used when the CRU backbone has no carbon atoms. An example is the polymer traditionally named poly(dimethylsiloxane) , which on the basis of structure would be named poly(oxydimethylsilylene) or poly(oxydimethylsilanediyl) . This nomenclature method has also been applied to inorganic and coordination polymers and to double-strand (ladder and spiro) organic polymers."... 

Catalysis - Porous three-dimensional networks can be viewed as zeolite mimics and can exhibits similar properties in some cases. The enclosed environment within charmels, akin to zeolites (Section 4.2) and discrete capsules (see Chapter 3, Section 3.5), can provide novel reactivity or catalytic ability and can be size- and shape-selective. Coordination polymers offer an advantage over traditional zeolites in that chiral channels are able to be constructed by using chiral ligands. 

In the last section, new coordination polymer chemistry related to sol-gel polymers is presented. In addition, two papers address phosphorus containing polymers and two address traditional coordination polymers used for a wide variety of applications. 

Fig. 32 Effect of analyte coordination in (a) a traditional molecular chemosensor system, (b) receptors wired in series in a conjugated polymer, (c) chemosensors grafted onto the surface of a nanoparticle, and (d) a fluorescent dendrimer. The curved arrows indicate the active...

The Cossee-Arlman mechanism as originally proposed has a weakness—the back-flip is required to explain isoselective placement since the two active (coordination) sites are assumed to be enantiotopic. However, the structure of the traditional Ziegler-Natta heterogeneous initiators is not sufficently understood to either support or reject the assumption of enantiotopic sites. Further, even if the sites are enantiotopic, there is no overwhelming reason why the polymer chain is more stable at one site than the other—which is the rationale for the back-flip. The mechanism of isoselectivity with various metallocene initiators is much better understood since these are initiators whose molecular structures are well-established [Busico and Cipullo, 2001 Busico et al., 1997, 1999 Cavallo et al., 1998 Ewen, 1999 Rappe et al., 2000 Resconi et al., 2000], Considerable advancements in understanding heterogeneous Ziegler-Natta initiators occur if one assumes that the active sites in these initiators mimic those in metallocene initiators. Two types of metallocene initiators offer possible models... 

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