Haichao Zhao, F. Sanda, T. Masuda
Oct 27, 2004
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0
Influential Citations
47
Citations
Journal
Macromolecules
Abstract
Copolymerizations of 1-pyrenebutyric acid N-propargylamide (PY) with chiral amino acid-based N-propargylamides, N-(tert-butoxycarbonyl)-l-valine-N-propargylamide (LV) and N-(tert-butoxycarbonyl)-d-alanine-N-propargylamide (DA) were conducted with (nbd)Rh+[η6-C6H5B-(C6H5)3] as a catalyst to obtain novel pyrene-functionalized helical poly(N-propargylamides). The controllable secondary structure of the copolymers by various compositions of the chiral amino acid units or solvent environment led to a controlled orientation of the side-chain pyrene. For instance, poly(PY30-co-LV70) exhibited a large specific rotation and a CD signal, while it emitted very weak fluorescence. On the other hand, poly(PY30-co-LV35-co-DA35) exhibited a small specific rotation and a CD signal, while it emitted fluorescence eight times larger than poly(PY30-co-LV70) did. The CD signal disappeared by the addition of MeOH to a THF solution of poly(PY30-co-LV70), while the fluorescence intensity increased.