Synthesis and Characterization of Diastereoisomeric Polyesters Derived from Bisphenols Bearing Vicinal Trifluoromethyl Groups

Abstract

Several diastereoisomeric polyesters bearing vicinal stereogenic centers in the backbone were synthesized to investigate the influence of diastereoisomerism on the properties of polymers. To hamper the free rotation of the Csp3 –Csp3 single bond between the stereogenic centers, bisphenol monomers containing vicinal CF3 moieties were designed and synthesized, wherein the CF3 group acts not only as a conformational stabilizer but also as a probe to provide information on stereoconfiguration. X-ray single-crystal structure and density functional theory (DFT) calculations indicate that the antimonomer tends to adopt a linear and extended configuration, whereas the most stable conformation for its diastereoisomer is kinked. These geometries resemble those possessed by the E and Z 1,2-disubstituted alkenes. The polymers based on these isomeric monomers display distinct glass transition state temperature (T g), crystallinities, mesoscopic morphology, and hydrophobicity, which can be attributed to the different polymer chain arrangement in the solid state. These observations support our hypothesis to utilize aliphatic moieties bearing vicinal stereogenic centers to mimic the geometry of the E and Z olefinic units, which serves as a new strategy to finely tune the polymer performance.

Dispersive 2D Triptycene-Based Crystalline Polymers: Influence of Regioisomerism on Crystallinity and Morphology

“…On the basis of continuing interests in exploring the unique influence of isomerism on the properties of polymers, , we envision that the distinct linking group arrangements of trifunctionalized 3D monomers would have a profound influence on the orientation of polymer growth, which in turn allows the manipulation of the crystallinity and the morphology of COFs/CPs via regioisomerism. Herein, we report our efforts to synthesize a series of crystalline and highly dispersive 2D CPs with 3D trifunctional triptycene monomers (Figure ).…”