Mutual complexation between π-π stacked molecular tweezers

Parker, M. P., Murray, C. A., Hart, L. R., Greenland, B. W., Hayes, W. ORCID: https://orcid.org/0000-0003-0047-2991, Cardin, C. J. ORCID: https://orcid.org/0000-0002-2556-9995 and Colquhoun, H. M. (2018) Mutual complexation between π-π stacked molecular tweezers. Crystal Growth and Design, 18 (1). pp. 386-392. ISSN 1528-7505 doi: 10.1021/acs.cgd.7b01376

Abstract/Summary

Aromatic and heterocyclic molecules which form electronically-complementary π-π stacked complexes have recently found extensive application in functional materials, molecular machines, and stimuli-responsive supramolecular polymers. Here we describe the design and synthesis of model compounds that self-assemble through complementary stacking motifs, paralleling those postulated to exist in high-molecular weight, healable, supramolecular polymer systems. Complexation studies using 1H NMR and UV-vis spectroscopy indicated formation of a complementary complex between a π-electron rich di-pyrenyl tweezer-motif and a tweezer-like, π electron deficient bis-diimide. The binding stoichiometry in solution between the chain folding diimide and the pyrenyl derivative was equimolar with respect to the two binding motifs and the resulting association constant was measured at Ka = 1200 ± 90 M-1. Single crystal X-ray analysis of this "tweezer-tweezer" complex showed a low-energy conformation of the triethylenedioxy linker within the bis-diimide chain-fold. Interplanar separations of 3.4 – 3.5 Å were found within the π-stacks, and supporting hydrogen bonds between pyrenyl amide NH groups and diimide carbonyl oxygens were identified.

Item Type	Article
URI	https://reading-clone.eprints-hosting.org/id/eprint/74417
Item Type	Article
Refereed	Yes
Divisions	Life Sciences > School of Chemistry, Food and Pharmacy > Department of Chemistry Interdisciplinary centres and themes > Chemical Analysis Facility (CAF) > Mass Spectrometry (CAF) Interdisciplinary centres and themes > Chemical Analysis Facility (CAF) > NMR (CAF) Interdisciplinary centres and themes > Chemical Analysis Facility (CAF) > Optical Spectroscopy (CAF) Interdisciplinary centres and themes > Chemical Analysis Facility (CAF) > Xray (CAF) Life Sciences > School of Chemistry, Food and Pharmacy > School of Pharmacy > Medicinal Chemistry Research Group
Publisher	American Chemical Society
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