Supramolecular Organogels Formed through Complementary Double-Helix Formation
Article first published online: 24 SEP 2013
Copyright © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim
Volume 79, Issue 1, pages 35–44, January 2014
How to Cite
Banno, M., Wu, Z.-Q., Makiguchi, W., Furusho, Y. and Yashima, E. (2014), Supramolecular Organogels Formed through Complementary Double-Helix Formation. ChemPlusChem, 79: 35–44. doi: 10.1002/cplu.201300108
- Issue published online: 24 JAN 2014
- Article first published online: 24 SEP 2013
- Manuscript Revised: 9 SEP 2013
- Manuscript Received: 21 MAR 2013
- Japan Society for the Promotion of Science
- Ministry of Education, Culture, Sports, Science, and Technology. Grant Numbers: P06350, 9164
- 1For reviews, see:
- 2For reviews, see:
- 3For foldamer or supramolecular helical assembly based organogelators, see:
- 5For leading references on the effect of chirality on gelation, see:
- 14For recent reviews, see:
- 15A similar enhancement of the CD intensity after treatment with a strong acid followed by neutralization with an amine was observed for a double-stranded helical polymer consisting of complementary homopolymers of chiral amidine and achiral carboxylic acid with m-terphenyl-based backbones; see reference .
- 16As dilute solutions in chloroform, the CD intensities of mixtures of 2 and 1 with different ee values monotonically increased with increasing ee values of 1, resulting in a completely linear relationship between the CD intensity and percentage ee of 1 (Figure S8 A in the Supporting Information).
- 17For chirality transfer from the chiral amidine residues to achiral ones covalently bonded to each other along their oligomer and copolymer strands in the presence of their complementary carboxylic acid strands through the duplex formation, see: reference [7g] and Polym. J. 2012, 44, 1071–1076., , , ,
- 18We attempted to obtain more convincing evidence for supramolecular polymer formations of (R)-1⋅2 during gelation, mainly by direct observations of the polymers by means of AFM. However, it was difficult to observe isolated supramolecular polymers on substrates by AFM. Instead, we could detect oligomers up to trimers by cold-spray ionization mass spectrometry; this may support supramolecular polymerization of the (R)-1⋅2 duplex (Figure S13 in the Supporting Information).
- 19The sliding abilities of the duplex strands are most likely to be related to their dissociation rates, and hence, binding affinities.
- 21Kinetic analyses of the chain-exchange reactions between (R)-1⋅2 and (S)-1, and (R)-4⋅5 and (S)-4 in chloroform revealed that direct chain exchange took place between them without dissociation of the duplexes via ternary complex formations ((R)-1⋅2⋅ (S)-1 and (R)-4⋅5⋅ (S)-4), and chain exchange between (R)-1⋅2 and (S)-1 was much faster than that between (R)-4⋅5 and (S)-4 in chloroform; half lives for the chain-exchange reactions were 9.1 min and 2 h, respectively (see Ref. ). Importantly, these chain-exchange processes require sliding of the two strands along one another, as shown in Figure 1.
- 22For reviews, see: