I. Tunable Luminescence in Dendronized Poly(phenyleneethynylene)s Through Post-Polymerization Chemical Modification II. Rigid, Helical Polymers Based Upon Chiral Hydrobenzoin

Abstract

Dendritic encapsulation of poly(phenyleneethynylene)s or PPEs has been shown to enhance photoluminescent quantum efficiency and facilitate energy transfer by funneling photonic energy absorbed on the dendron periphery efficiently to the conjugated polymeric core. The research presented herein focuses on incorporating degradable dendron onto PPEs, examining whether or not similar benefits were conferred upon the proposed system and controlling polymer luminescence through the elimination of the insulating macromolecules. PPEs appended with disassembling dendrons of various generation sizes were synthesized and their optical properties studied. Polymer luminescence was then quenched via chemical degradation of the disassembling dendrons. Furthermore, the macromolecules resulting from disassembly exhibited tunable luminescence properties upon manipulation of pH. Consequently, it was determined that polymer luminescence could be controlled upon forming phenolic moieties along the PPE backbone. Tunable emission was later realized in the thin film as well through the integration of crosslinkable dendrons onto the polymer core.Recently, helical synthetic linear polymers have demonstrated the ability to facilitate stereoselective processes such as catalysis, recognition and separation. Consequently, it has become increasingly desirable to develop new platforms capable of imparting asymmetry. The work presented herein describes the synthesis of a series of polymers based upon chiral hydrobenzoin and the subsequent conformational analysis performed on these materials. It was envisioned that these polymeric materials might inherently possess conformational asymmetry and as result could be able to impart configurationally chirality by introducing a diastereomeric bias for the formation of one enantiomer over the other during the course of the reaction.