Designing Highly Ordered Helical and Nonhelical Porous Crystalline and Disordered Nonhelical Columnar Liquid Crystalline Self-Organizations.

ABSTRACT

Helical self-organizations are equilibrium structures responsible for the assembly of nonequilibrium and equilibrium living and synthetic systems. Racemic helical columnar systems transform into one-handed systems with the help of enantiomerically rich or pure components. Racemic, enantiomerically rich, and enantiomerically pure helical periodic arrays of columns are analyzed by oriented fiber X-ray diffraction (XRD). With few exceptions, highly ordered helical 3-D organizations as generated from homochiral columns cannot be obtained from achiral, racemic, or enantiomerically rich helical columns. Here, we report an unprecedented class of nonhelical porous ordered, disordered nonhelical columnar liquid crystalline (LC) self-organizations and columnar liquids constructed from AB4 to AB9 isomeric terphenyls by molecular design unwinding of a 3-D helical organization. A library of 16 nonhelical porous ordered, disordered columnar and four liquids was designed by employing as a model a closely related achiral AB4 meta-terphenyl, which self-organizes one of the most perfect synthetic ordered columnar hexagonal helices known. A general molecular mechanism to unwind highly ordered 3-D helices into nonhelical porous columnar ordered LCs and liquids was elaborated to design this transformation, which provided unprecedented nonequilibrium synthetic systems. This methodology is expected to be general for transformation of helical macromolecular and supramolecular organizations into nonhelical crystals, LCs, and liquids.