Polycatenar compounds

Polycatenar compounds, with more than one terminal chain at each end of a rod-like molecule can also exhibit columnar phases, although they possess a linear molecular structure. Three linear molecules aggregate together to form a self-assembled disc. These discs then stack up to form a fluid columnar structure. Non-dispersive charge-carrier mobility in such polycatenar compounds has also been found. ... 

Polycatenar compounds possess two to six flexible chains attached at the terminal rings of large rod-like cores, and are called bi-, tri-, tetra-, penta- and hexacatenar compounds, respectively. Malthete et al. [21] have published a good review that explains many details about this substance class. 

Table 42. Phase behaviour of lateral long-chain substituted, swallow-tailed and polycatenar compounds.

The simultaneous occurrence of nematic, cubic, layer and columnar structures in pure mesogens is of great importance to bridging the gap between calamitic and discotic molecules and the corresponding mesophases. Smectic, cubic and columnar phases have also been described in polycatenar compounds, and thus double-swallow-tailed mesogens can also be considered to be a special case of tetracatenar compounds (see Chap. XII of this volume). 

Heilmeier displays 281 polyamides, biaxial nematics 940 polycatenar compounds, thermotropic cubic... 

Compounds with 2,4-disubstituted endstanding benzenes are the bridge to substances with several endstanding chain-like substituents, now called polycatenar compounds (Table 2.3). It seems that the symmetry of the mesophases depends on the number of paraffinic chains in comparison to the core size. " Polycatenar molecules having four to six long paraffinic chains are a good example of this idea since they present a smectic and... 

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