| 학회 | 한국고분자학회 |
| 학술대회 | 2004년 봄 (04/09 ~ 04/10, 고려대학교) |
| 권호 | 29권 1호, p.29 |
| 발표분야 | 고분자 합성 |
| 제목 | Synthesis and Properties of Amino Acid-Based Polyacetylenes |
| 초록 | Amino acids are constituents of proteins, typical biological polymers, and not only biologically important but also useful for chiral auxiliaries and building blocks in organic synthesis. Amino acid-based synthetic polymers are expected to show biocompatibility and biodegradability similarly to polypeptides. On the other hand, polyacetylenes possess alternating double bonds in the main chain, which endows them with electrical conductivity and gas permeability, etc. It is expected that amino acid-containing polyacetylenes will combine these characteristics together and lead to the development of new functions. We synthesized several optically active N-propargylamides from amino acids, and polymerized them with a rhodium catalyst to obtain polyacetylenes bearing amino acid moieties in the side chain (Scheme 1). {image1} Polymers with moderate molecular weights (Mn 10,000-30,000) were obtained in good yields. L-Alanine-derived polymer (R = CH3 in Scheme 1) exhibited large specific rotation ([α]D =-1400 o) and CD signal ([ θ]max = -3.43x104 deg.cm2 .dmol-1 at 390 nm) in chloroform, indicating that it takes a helical conformation with one-handed screw sense. On the other hand, the corresponding poly(N-methylpropargylamide) and poly(propargylester) showed no evidence for a helical structure. The helical structure of the polymer was deformed by the addition of MeOH. Consequently, it is strongly suggested that hydrogen bonding between the amide groups of the side chain plays an important role for helix formation. In the copolymerization of the monomer with the optical isomer, nonlinear relationships were observed in the specific rotation, CD and UV-vis spectroscopies with respect to the monomer content. Chiral amplification was observed in the copolymerization of the monomer with achiral N-propargylamides, i.e., the copolymer with the chiral unit as low as 10% exhibited nearly the same helix content as the homopolymer. |
| 저자 | Fumio Sanda |
| 소속 | Department of Polymer Chemistry |
| 키워드 | |
