Materials chemistry: from glasses to liquid crystals to crystals through molecular symmetry and functionalization

The authors present results on a family of homologous polymers which have structures ranging from glasses to liquid crystals to crystals. The various three dimensional structures are observed with molecular changes such as ordering and disordering of absolute configuration in chiral repeats, the shortening of aliphatic spacers in the polymer's backbone, and the removal of large dipole moments from the chain's structure. Two examples of molecular tools used to design members of the family include the appending of strong dipoles to a stereogenic center with controlled configuration, and the construction of chains with translational polar symmetry. Molecular structures were characterized largely by a variety of NMR methods and three dimensional structures were probed by electron diffraction, polarized optical microscopy and differential scanning calorimetry.