Main-Chain Stiffness and Helical Conformation of a Poly(quinoxaline-2,3-diyl) in Solution

• Nagata, Yuuya

• Hasegawa, Hirokazu

• Terao, Ken

• Suginome, Michinori

Abstract

Nagata Y., Hasegawa H., Terao K., et al. Main-Chain Stiffness and Helical Conformation of a Poly(quinoxaline-2,3-diyl) in Solution. Macromolecules, 48(21), 7983-7989, October 26, 2015. Copyright © 2015, American Chemical Society. https://doi.org/10.1021/acs.macromol.5b01919.

Light and small-angle X-ray scattering and viscosity measurements in tetrahydrofuran at 25 °C were made for nine helical poly[5,8-dimethyl-6,7-bis(propoxymethyl)quinoxaline-2,3-diyl] samples ranging in the weight-average molar mass Mw from 8 × 103 g mol-1 to 6 × 105 g mol-1 to determine the particle scattering function, the radius of gyration, and the intrinsic viscosity as a function of Mw. The dimensional and hydrodynamic properties were consistently explained in terms of the Kratky-Porod wormlike chain. The helix pitch per residue h (or the contour length per residue) and the chain stiffness parameter λ-1 (the Kuhn segment length or twice of the persistence length) were estimated to be h = 0.19 nm and λ-1 = 43 ± 3 nm. The former parameter corresponds to an internal rotation angle of about 120° which is substantially the same as the most stable helical structure estimated from the internal rotation potential. The latter one (λ-1) indicates that the poly(quinoxaline-2,3-diyl) has a rigid helical main chain of which the dihedral angle between adjacent monomer units are restricted by steric hindrance.

Journal

• Macromolecules

  Macromolecules 48 (21), 7983-7989, 2015-10-26

  American Chemical Society

Keywords

• Materials Chemistry
• Inorganic Chemistry
• Polymers and Plastics
• Organic Chemistry

Details

• CRID: 1050018218947501312
• NII Article ID: 120007053189
• NII Book ID: AA0071963X
• DOI: 10.1021/acs.macromol.5b01919
• ISSN: 15205835
• ISSN: 00249297
• HANDLE: 11094/81806
• Web Site: https://pubs.acs.org/doi/pdf/10.1021/acs.macromol.5b01919
• Text Lang: en
• Article Type: journal article
• Data Source:
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  • CiNii Articles
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