Conformational modulation of sequence recognition in synthetic macromolecules

Zhu, Z., Cardin, C. ORCID: https://orcid.org/0000-0002-2556-9995, Gan, Y., Murray, C. A., White, A. J. P., Williams, D. J. and Colquhoun, H. M. (2011) Conformational modulation of sequence recognition in synthetic macromolecules. Journal of the American Chemical Society, 133 (48). pp. 19442-19447. ISSN 0002-7863 doi: 10.1021/ja2067115

Abstract/Summary

The different triplet sequences in high molecular weight aromatic copolyimides comprising pyromellitimide units ("I") flanked by either ether-ketone ("K") or ether-sulfone residues ("S") show different binding strengths for pyrene-based tweezer-molecules. Such molecules bind primarily to the diimide unit through complementary π-π-stacking and hydrogen bonding. However, as shown by the magnitudes of 1H NMR complexation shifts and tweezer-polymer binding constants, the triplet "SIS" binds tweezer-molecules more strongly than "KIS" which in turn bind such molecules more strongly than "KIK". Computational models for tweezer-polymer binding, together with single-crystal X-ray analyses of tweezer-complexes with macrocyclic ether-imides, reveal that the variations in binding strength between the different triplet sequences arise from the different conformational preferences of aromatic rings at diarylketone and diarylsulfone linkages. These preferences determine whether or not chain-folding and secondary π−π-stacking occurs between the arms of the tweezermolecule and the 4,4'-biphenylene units which flank the central diimide residue.

Item Type	Article
URI	https://reading-clone.eprints-hosting.org/id/eprint/25448
Identification Number/DOI	10.1021/ja2067115
Refereed	Yes
Divisions	Life Sciences > School of Chemistry, Food and Pharmacy > Department of Chemistry
Publisher	American Chemical Society
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