Macroscopic Mesogens with Flexible Side-Chains

A large number of inorganic layer crystals such as micas, sodium silicates, niobate, uranate, vanadate, titanate, zirconium phosphate, graphitic acids, crystalline silicic acids, vanadium oxyhydrate, calcium phosphoric acid esters, and titanium disulfide develop alkyl crystals between their rigid crystal layers by ion exchange with, for example, alkyl ammonium salts and by intercalation inorganic 

Paraffin crystals held by a one-dimensional macroscopic rigid mesogen were observed for poly(L-glutamate)s with long n-alkyl side chains 

A large series of poly(l,4-phenyleneterephthalate)s and poly(l,4-phenylenetereph-thalamide)s with two alkoxides of up to 18 CH -groups each per repeating unit have been made Fot the terephthalates with more than 7 CH2-groups per side-chain 

Combinations of rigid and flexible segments complicate crystal structures considerably. In particular is was shown in Sect. 5.1 that seemingly rigid p-phenyl sequences may still show partial and complete ring-flips about the ring axes. The motion and introduction of defects based on ring-flips is much less cooperative than found for many flexible molecules. 

The smallest members of the series of stiff rings (benzene, naphthalene, furan and substituted benzenes) are similar to the small cycloalkanes (Sect. 3.1) and are capable of beginning jump-motion between symmetry related positions without thermal transition. Destroying the symmetry causes similar motion to be connected with entropy-gain in a first-order transition (furan compared to benzene). With 

---