Monomeric structures lead-containing polymers

Dendrimers are a relatively new class of macromolecules different from the conventional linear, crosslinked, or branched polymers. Dendrimers are particularly interesting because of their nanoscopic dimensions and their regular, well-defined, and highly branched three-dimensional architecture. In contrast to polymers, these new types of macromolecules can be viewed as an ordered ensemble of monomeric building blocks. Their tree-like, monodispersed structures lead to a number of interesting characteristics and features globular, void-containing shapes, and unusual physical properties [107-111]. 

A reduction in the molecular mobility of a polymer chain as an organic stationary phase would lead to an increase in the selectivity in HPLC. Porphyrin derivative-bonded phases show a unique shape selectivity by retaining planar PAHs. " Similar molecular-planarity selectivity is also observed in cholesteryl-lO-undecenoate- and 4,4 -dipentyldiphenyl-bonded phases. These phases contain rigid structures, and hence the limited mobility in their organic phases contributes to the shape selectivity. Similar phenomenon of selectivity increase can be observed in the comparison of the retention behaviors of polymeric and monomeric ODSs. ... 

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