Abstract
This chapter is concerned with VCD application to gels. When a chiral low molecular weight gelator (LMWG) forms a gel from an organic solvent, it often leads to the appearance of helically wound fibrils. S- or R-12-hydroxystearic acid (denoted as S- or R-12-HOA), for example, forms a transparent gel from benzene. Helical fibrils (e.g., 100–200 nm in pitch length) are observed by electron microscopy. When VCD spectra are measured on the gels, enormously large VCD signals are observed. The enhancement is rationalized in terms of the mechanism that gelator molecules are linked stereoregularly under the uniform conformation. The conformation of a gelator molecule is deduced by analyzing VCD spectra with the help of theoretical simulation. It presents an example of VCD application to supramolecular chirality. VCD studies are further extended to gels formed by LMWGs with perfluoroalkyl chains. Attention is focused on how the helicity of a fibril is related to the molecular chirality of a perfluoroalkyl chain.
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References
F. Fages (ed.), Low Molecular Mass Gelators, Design, Self-assembly, Function (Springer, 2005)
F.G. Weiss, P. Terech (eds.), Molecular Gels: Materials with Self-assembled Fibrillar Networks (Springer, 2006)
L.A. Estroff, A.D. Hamilton, Water gelation by small organic molecules. Chem. Rev. 104, 1201 (2004); A. Aggeli, I.A. Nyrkova, M. Bell, R. Harding, L. Carrick, T.C.B. McLeish, A.N. Semenov, N. Boden, Hierarchical self-assembly of chiral rod-like molecules as a model for peptide b-sheet tapes, ribbons, fibrils, and fibers. Proc. Natl. Acad. Sci. U.S.A. 98, 11857–11862 (2001)
H. Sato, K. Hori, T. Sakurai, A. Yamagishi, Long distance chiral transfer in a gel: experimental and ab initio analyses of vibrational circular dichroism spectra of R- and S-12 hydroxyoctadecanoic acid gels. Chem. Phys. Lett. 467, 140–143 (2008)
H. Sato, A new horizon for vibrational circular dichroism spectroscopy: a challenge for supramolecular chirality. Phys. Chem. Chem. Phys. 22, 7671–7679 (2020)
H. Sato, T. Yajima, A. Yamagishi, Chiroptical studies on supramolecular chirality of molecular aggregates. Chirality 27, 659–666 (2015)
T. Tachibana, T. Mori, K. Hori, New type of twisted mesophase in jellies and solid films of chiral 12-hydroxyoctadecanoic acid. Nature 278, 578–579 (1979)
P. Terech, V. Rodriguez, J.D. Barnes, G.B. McKenna, Organogels and aerogels of racemic and chiral 12-hydroxyoctadecanoic acid. Langmuir 10, 3406–3418 (1994)
T. Sakurai, Y. Masuda, H. Sato, A. Yamagishi, H. Kawaji, T. Atake, K. Hori, A comparative study on chiral and racemic 12-hydorxyoctadecanoic acids in the solutions and aggregation states: does the racemic form really form a gel? Bull. Chem. Soc. Jpn. 83, 145–150 (2010)
H. Sato, T. Sakurai, A. Yamagishi, Comparison of vibrational circular dichroism between the langmuir-blodgett films and gels of 12-hydroxyoctadecanoic acid. Chem. Lett. 40, 25–27 (2011)
S. Dieterich, S. Prévost, C. Dargel, T. Sottmann, F. Giesselmann, Synergistic structures in lyotropic lamellar gels. Soft Matter 16, 10268–10279 (2020)
S. Dieterich, T. Sottmann, F. Giesselmann, Gelation of lyotropic liquid-crystal phases-the interplay between liquid crystalline order and physical gel formation. Langmuir 35, 16793–16802 (2019)
M. Laupheimer, N. Preisig, C. Stubenrauch, The molecular organogel n-decane/12-hydroxyoctadecanoic acid: sol–gel transition, rheology, and microstructure. Colloids Surf. A: Physicochem. Eng. Aspect 469, 3150325 (2015)
K. Aramaki, S. Koitani, E. Takimoto, M. Kondob, C. Stubenrauch, Hydrogelation with a water-insoluble organogelator—surfactant mediated gelation (SMG). Soft Matter 15, 8896–8904 (2019)
M.A. Rogers, S. Abraham, F. Bodondics, R.G. Weiss, Influence of the hydroxyl position in racemic hydroxyoctadecanoic acids on the crystallization kinetics and activation energies of gels and dispersions in mineral oil. Cryst. Growth Des. 12, 5497–5504 (2012)
D.A.S. Grahame, C. Olauson, R.S.H. Lam, T. Pedersen, F. Borondics, S. Abraham, R.G. Weissc, M.A. Rogers, Influence of chirality on the modes of self-assembly of 12-hydroxystearic acid in molecular gels of mineral oil. Soft Matter 7, 7359–7365 (2011)
Y. Lan, M.G. Corradini, R.G. Weiss, S.R. Raghavan, M.A. Rogers, To gel or not to gel: correlating molecular gelation with solvent parameters. Chem. Soc. Rev. 44, 6035–6058 (2015)
K. Hanabusa, M. Yamada, M. Kimura, H. Shirai, Prominent gelation and chiral aggregation of alkylamides derived from trans-l,2-diaminocyclohe. Angew. Chem. Int. Ed. 35, 1949 (1996)
H. Sato, T. Nakae, K. Morimoto, K. Tamura, Critical effects of alkyl chain length on fibril structures in benzene-trans(RR)- or (SS)-N, N′-Alkanoyl-1, 2-diaminocyclohexane gels. Org. Biomol. Chem. 10, 1581–1586 (2012)
H. Sato, E. Nogami, T. Yajima, A. Yamagishi, Terminal effects on gelation by low molecular weight chiral gelators. RSC Adv. 4, 1659–1665 (2014)
K. Monde, N. Miura, M. Hashimoto, T. Taniguchi, T. Inabe, Conformational analysis of chiral helical perfluoroalkyl chains by VCD. J. Am. Chem. Soc. 128, 6000–6001 (2006)
H. Sato, T. Yajima, A. Yamagishi, Molecular origin for helical winding of fibrils formed by perfluorinated gelators. Chem. Commun. 47, 3736–3738 (2011)
K. Kohno, K. Morimoto, N. Manabe, T. Yajima, A. Yamagishi, H. Sato, Promotion effects of optical antipodes on the formation of helical fibrils: chiral perfluorinated gelators. Chem. Commun. 48, 3860–3862 (2012)
H. Sato, T. Yajima, A. Yamagishi, An intermediate state in gelation as revealed by vibrational circular dichroism spectroscopy. RSC Adv. 4, 25867–25870 (2014)
T. Yajima, E. Tabuchi, E. Nogami, A. Yamagishi, H. Sato, Perfluorinated gelators for solidifying fluorous solvents: effects of chain length and molecular chirality. RSC Adv. 5, 80542–80547 (2015)
H. Sato, T. Yajima, A. Yamagishi, Helical inversion of gel fibrils by elongation of perfluoroalkyl chains as studied by vibrational circular dichroism. Chirality 28, 361–364 (2016)
A. Yamagishi, Y. Umemura, K. Tamura, T. Yajima, H. Sato, Langmuir-blodgett films of chiral perfluorinated gelators: effects of chirality and chain length on two-dimensional behavior. Bull. Chem. Soc. Jpn 94, 377–381 (2021)
H. Torii, H. Sato, Intermediate length-scale chirality related to the vibrational circular dichroism intensity enhancement upon fibril formation in a gelation process. Phys. Chem. Chem. Phys. 20, 14992–14996 (2018)
T. Sasaki, A. Egami, T. Yajima, H. Uekusa, H. Sato, Unusual molecular and supramolecular structures of chiral low molecular weight organogelators with long perfluoroalkyl chains. Cryst. Growth Des. 18, 4200–4205 (2018)
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Sato, H., Yoshida, J., Yamagishi, A. (2024). Molecular Organization of Gel Fibrils as Revealed by VCD. In: Multi-dimensional Vibrational Circular Dichroism. Springer, Singapore. https://doi.org/10.1007/978-981-97-0391-3_4
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DOI: https://doi.org/10.1007/978-981-97-0391-3_4
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