2006 Fiscal Year Final Research Report Summary
Studies on Asymmetric Synthesis, Structure, and Function of Optically Active Poly(methacrylamide) Derivatives
| Project/Area Number |
17550116
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| Research Category |
Grant-in-Aid for Scientific Research (C)
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| Allocation Type | Single-year Grants |
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| Section | 一般 |
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| Research Field |
Polymer chemistry
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| Research Institution | Nagoya University |
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Principal Investigator |
OKAMOTO Yoshio Nagoya University, EcoTopia Science Institute, Professor, エコトピア科学研究所, 教授 (60029501)
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| Project Period (FY) |
2005 – 2006
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| Keywords | Helix-Sense-Selective Polymerization / Methacrylamide / Radical Polymerization / Anionic Polymerization / Optically Active Polymer / Asymmetric Polymerization |
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| Research Abstract |
1. The radical polymerization of the methacrylamides having a bulky side group, such as N-[(4-butyl)triphenylmethyl]methacrylamide (BuTrMAM) and N-[(4-butylphenyl)dibenzosuberyl]methacrylamide (BuPDBSMAM), in the presence of (+)-menthol or (-)-menthol was carried out in order to attain the helix-sense-selective polymerization leading to the optically active polymers. The tacticity of the polymers was estimated to be nearly 100% isotactic from the ^1H NMR spectra of the polymers in D_2SO_<4->. The circular dichroism (CD) spectra of the polymers suggested that the polymers have a helical conformation with an excess right-or left-handed helicity. The radical copolymerization of BuTrMAM with an optically active comonomer, such as N-[(R)-(+)-1-(1-naphthyl)ethyl]methacrylamide ((+)-NEMAM), was also carried out. The optical activity of the copolymers significantly depended on the comonomer contents. When (+)-NEMAM content was low in the copolymer, the (+)-NEMAM units effectively induced the one-handed helicity consisting of BuTrMAM monomeric sequences.
2. BuTrMAM was polymerized with the chiral anionic initiator systems consisting of n-Bu_4ZnLi_2 and halogeno sugars, such as 2,3,4,6-tetra-0-acetyl-α-D-galactopyranosyl bromide. The ^1H NMR spectra in D_2SO_4 suggested that the polymers were highly isotactic, and the initiating chain end of polymers has a sugar residue. The obtained polymers exhibited an optical activity, and the halogeno sugars affected the specific rotations and Cotton effect in the CD spectra. These results indicate that the polymers prepared by the n-Bu_4ZnLi_2/halogeno sugars initiator systems have a helical conformation with an excess right- or left-handed helicity.
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