Synthesis of optically active poly(N‐propargylsulfamides) with helical conformation |
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| Authors: | Zhigang Zhang Jianping Deng Weiguo Zhao Jianmin Wang Wantai Yang |
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| Institution: | 1. Department of Polymer Science, College of Materials Science and Engineering, Beijing University of Chemical Technology (BUCT), Beijing 100029, China;2. State Key Laboratory of Chemical Resource Engineering, Beijing University of Chemical Technology, Beijing 100029, China;3. Hebei Normal University of Science and Technology, Hebei, Qinhuangdao 066004, China;4. State Key Laboratory of Chemical Resource Engineering, Beijing University of Chemical Technology, Beijing 100029, ChinaDepartment of Polymer Science, College of Materials Science and Engineering, Beijing University of Chemical Technology (BUCT), Beijing 100029, China |
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| Abstract: | A novel chiral N‐propargylsulfamide monomer ( 1a ) and its enantiomer ( 1b ) were synthesized and polymerized with (nbd)Rh+B?(C6H5)4 as a catalyst providing poly(1) (poly( 1a ) and poly( 1b )) in high yields (≥99%). Poly(1) could take stable helices in less polar solvents (chloroform and THF), demonstrated by strong circular dichroism signals and UV–vis absorption peaks at about 415 nm and the large specific rotations; but in more polar solvents including DMF and DMSO, poly(1) failed to form helix. Quantitative evaluation with anisotropy factor showed that the helical screw sense had a relatively high thermal stability. These results together with the IR spectra measured in solvents showed that hydrogen bonding between the neighboring sulfamide groups is one of the main driving forces for poly(1) to adopt stable helices. In addition, copolymerization of monomer 1a and monomer 2 was conducted, the solubility of poly(1) was improved drastically. However, the copolymerization had adverse effects on the formation of stable helices in the copolymers. © 2006 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 45: 500–508, 2007 |
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| Keywords: | chiral conjugated polymers helical conformation N‐propargylsulfamide polyacetylenes |
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