Molecules with Rod-Like Mesogens

Many molecules with rod-like mesogens have been analyzed in the liquid crystalline phase, but only few of the low-temperature pramrsor crystals have been studied. Among them one might find many conformationally disordered crystals A survey 

It was shown early that the rod-like molecules of liquid crystals are imbricated in 

N-(4-ethoxybenzylidene)-4-n-birtyl aniline (R=C2Hs-) Ta=306K Tj=349K 

The first disordering goes to the condis phase (c), the second to the smectic phase (s), the third to the nematic phase (n). Data from Ref. 

Another example of the existence of condis crystalline polymorphs between liquid crystal and crystal phase is OOBPD. Table 5.4 contains a listing of the observed transitions Again, the combined entropies of transition from the condis crystal K1 to the melt [41.6 J/(K mol)] are what is expected for fusion of a single, rigid, non-spherical motif (see Sect. 1). 

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