Central rigid core length

The importance of the effect of the length of the central rigid core of the structure on the thermal stability is illustrated by the following comparison ... 

Tetracatenars 2mm-2mm Within the homologous series with a six-benzene-ring core 26 [24], only one type of mesophase has been detected by optical observations. The textures are fan-shaped, with developable domains in every way similar to those of the Oh phase of tetracatenars 2mp-2mp. As an example, for the compound with n = 10 K 76 °C Oh 110 °C I. Despite the unusual length of the central rigid part, the transition temperatures are surprisingly low (Table 10), a fact evidently connected with the meta position of all the alkyloxy chains. 

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