Hydrocarbon Networks with Very Short Aromatic Segments

2 Hydrocarbon Networks with Very Short Aromatic Segments 

Aromatic networks prepared from long segments end-capped by ethynyl groups will be described in Sect. 3.1.6.3, and in Sect. 3.2.3 we shall describe the two-step preparation of substantially rigid networks using the reactions of ethynyl groups present in long linear chains to form interchain crosslinks. 

The polymeric products appear as fine particulate suspension. It will be of interest to determine whether this is due to the relatively low concentration in which the polymerization reaction was carried out, or to an inherent inability of these systems to form infinite networks. The significant swelling of the networks in various solvents implies the presence of substantial amount of network defects and inhomogeneity [383]. 

An interesting family of phenylacetylene rigid macrocyclic compounds, potentially capable of subsequent network formation, was recently reported by Moore and co-workers [386a]. This promises to be an exciting new advance along the road to open rigid networks. 

One gathers from the above that, despite substantial effort, we have on hand only the beginning of what promises to be a fascinating field of well-defined rigid networks based on aromatic or cycloaliphatic end-capped stiff hydrocarbon segments. 

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