POLY 436 |
| Recently, our research group studied in details the self-assembly of (2S)-methylbutyl substituted bis(alkoxy)-p-phenylenevinylene oligomers (OPVs) terminated with a tridodecyloxybenzene moiety on one end and either a diaminotrizaine (OPVnT) or a ureido-s-triazine (OPVnUT) hydrogen-bonding unit on the other end. We demonstrated that the self-assembly proceeds through a cooperative mechanism, with nucleation followed by elongation of the OPV fibers. In this contribution, we investigate further the self-assembly mechanism by looking at the chiral amplification effect. To carry out this study, OPV4T and OPV4UT with 2R-methylbutyl, racemic 2-methylbutyl and achiral butyl side chains were synthesized. Enantiomerically pure intermediate 2R-methylbutanol was obtained via a powerful and versatile asymmetric synthesis using a chiral oxazolidinone as chiral auxiliary. The amplification of chirality in the OPV stacks has been investigated with sergeant-and-soldier and majority rule experiments. The crucial role of the solvent in the self-assembly is revealed by the odd-even solvent effect and chiral solvation. Achiral OPVs were found to form more stable stacks and shows remarkable chirality induction with chiral guest molecules. |
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Conjugated Polymer Materials and Hybrids: Synthesis, Macromolecular Assemblies, and Nanostructures
6:00 PM-8:00 PM, Tuesday, August 21, 2007 BCEC -- Exhibit Hall - B2, Poster
Division of Polymer Chemistry |