15508 DOI: 10.1021/la101494t Langmuir 2010, 26(19), 15508–15515 Published on Web 09/01/2010 pubs.acs.org/Langmuir © 2010 American Chemical Society Alkoxy Tail Length Dependence of Gelation Ability and Supramolecular Chirality of Sugar-Appended Organogelators Jiaxi Cui, Yijun Zheng, Zhihao Shen,* and Xinhua Wan* Beijing National Laboratory for Molecular Sciences, Key Laboratory of Polymer Chemistry and Physics of Ministry of Education, College of Chemistry and Molecular Engineering, Peking University, Beijing 100871, China Received April 15, 2010. Revised Manuscript Received August 12, 2010 A series of sugar-appended organogelators, 4-(4 0 -alkoxyphenyl)phenyl-β-O-D-glucoside (GBCn, where n =1-12 denotes the number of carbon atom in the tail), are synthesized to elucidate the effect of terminal chain length on their gelation and chiral expression abilities in gels. In the mixture of H 2 O/dioxane (60/40 v/v), GBCn undergoes a phasic evolution of precipitation-solution-gel-precipitation-gel as its tail length increases from n = 1, 2, 3-6, and 7-10 to 11-12, respectively. Helical ribbons are observed in gels, but platelet-like structures are the dominant morphologies in the systems that precipitation happens. Combinatory analyses of microscopic, spectroscopic, and diffraction results reveal that the self-assembly into interdigitated bilayer structures of GBCn is driven by hydrogen bondings of sugar heads, π-π interactions of biphenyl rods, and hydrophobic interactions of alkoxy tails. The helical-morphology formation is caused by the significant steric repulsion between chiral moieties on the condition of the disordering or the size of alkoxy chains reaching the threshold of helical twisting and bending. Introduction Low-molecular-weight gelators (LMWGs) have attracted a great deal of attention due to their impacts on the fields of mole- cular self-assemblies, smart materials, controlled chemical release, and hierarchically ordered structures. 1 Many LMWGs with excellent gelation ability are currently available. Examples include steroids, 1a,2,3 amide- and urea-type compounds, 4,5 nucleobase derivatives, 6,7 sugar amphiphiles, 8-11 gemini amphiphiles, 12,13 and so forth. 1,14 As a compromised result of complicated non- covalent interactions, these small organic compounds self- assemble into three-dimensional networks spanning over the whole system to immobilize solvent molecules. 15,16 This subtle self- assembly process is influenced by a variety of factors, including solvent, concentration, additive, temperature, and, especially, *Corresponding authors: tel 86-10-62754518, fax 86-10-62751708, e-mail zshen@pku.edu.cn (Z.S.); tel 86-10-62754187, fax 86-10-62751708, e-mail xhwan@pku.edu.cn (X.W.). (1) (a) Terech, P.; Weiss, R. G. Chem. Rev. 1997, 97, 3133–3160. (b) van Esch, J. H.; Feringa, B. L. Angew. Chem., Int. Ed. 2000, 39, 2263–2266. (c) van Bommel, K. J. C.; Friggeri, A.; Shinkai, S. Angew. Chem., Int. Ed. 2003, 42, 980–999. (d) Estroff, L. A.; Hamilton, A. D. Chem. Rev. 2004, 104, 1201–1218. (e) Weiss, R. G., Terech, P., Eds. Molecular Gels: Materials with Self-Assembled Fibrillar Networks; Springer: Dordrecht, Netherlands, 2005. (f) Fages, F., Ed. Low Molecular Mass Gelators: Design, Self-Assembly, Function; Topics in Current Chemistry; Springer: New York, 2005; Vol. 256. (g) A series of reports about gelators can be seen in: Langmuir 2009, 25, 8369-8840. (2) (a) Lin, Y. C.; Weiss, R. G. Macromolecules 1987, 20, 414–417. (b) Murata, K.; Aoki, M.; Nishi, T.; Ikeda, A.; Shinkai, S. J. Chem. Soc., Chem. Commun. 1991, 1715– 1718. (3) (a) Fujita, N.; Mukhopadhyay, P.; Shinkai, S. Annu. Rev. Nano Res. 2006, 1, 385–428. (b)  Zini c, M.; V€ ogtle, F.; Fages, F. In Topics in Current Chemistry; Springer- Verlag: New York, 2005; Vol. 256, pp 39-76. (c) George, M.; Weiss, R. G. Acc. Chem. Res. 2006, 39, 489–497. (4) (a) Shi, C.; Huang, Z.; Kilic, S.; Xu, J.; Enick, R. M.; Beckman, E. J.; Carr, A. J.; Melendez, R. E.; Hamilton, A. D. Science 1999, 286, 1540–1543. (b)  Caplar, V.;  Zini c, M.; Pozzo, J.-L.; Fages, F.; Mieden-Gundert, G.; V€ ogtle, F. Eur. J. Org. Chem. 2004, 2004, 4048–4059. (5) Fages, F.; V€ ogtle, F.;  Zini c, M. In Topics in Current Chemistry; Springer- Verlag: New York, 2005; Vol. 256, pp 77-131. (6) (a) Yanagawa, H.; Ogawa, Y.; Furuta, H.; Tsuno, K. J. Am. Chem. Soc. 1989, 111, 4567–4570. (b) Shimizu, T.; Iwaura, R.; Masuda, M.; Hanada, T.; Yase, K. J. Am. Chem. Soc. 2001, 123, 5947–5955. (c) Iwaura, R.; Yoshida, K.; Masuda, M.; Yase, K.; Shimizu, T. Chem. Mater. 2002, 14, 3047–3053. (d) Moreau, L.; Barth el emy, P.; El Maataoui, M.; Grinstaff, M. W. J. Am. Chem. Soc. 2004, 126, 7533–7539. (7) Araki, K.; Yoshikawa, I. In Topics in Current Chemistry; Springer-Verlag: New York, 2005; Vol. 256, pp 133-165. (8) (a) Bhattacharya, S.; Acharya, S. N. G. Langmuir 1999, 16, 87–97. (b) Bhattacharya, S.; Acharya, S. N. G. Chem. Mater. 1999, 11, 3504–3511. (c) Srivastava, A.; Ghorai, S.; Bhattacharjya, A.; Bhattacharya, S. J. Org. Chem. 2005, 70, 6574–6582. (d) Bhattacharya, S.; Srivastava, A.; Pal, A. Angew. Chem., Int. Ed. 2006, 45, 2934–2937. (9) (a) Yoza, K.; Amanokura, N.; Ono, Y.; Akao, T.; Shinmori, H.; Takeuchi, M.; Shinkai, S.; Reinhoudt, D. N. Chem.;Eur. J. 1999, 5, 2722–2729. (b) Tamaru, S.; Nakamura, M.; Takeuchi, M.; Shinkai, S. Org. Lett. 2001, 3, 3631–3634. (c) Gronwald, O.; Shinkai, S. Chem.;Eur. J. 2001, 20, 4328–4334. (d) Jung, J. H.; Shinkai, S.; Shimizu, T. Nano Lett. 2002, 2, 17–20. (e) Jung, J. H.; John, G.; Yoshida, K.; Shimizu, T. J. Am. Chem. Soc. 2002, 124, 10674–10675. (f) Friggeri, A.; Gronwald, O.; van Bommel, K. J. C.; Shinkai, S.; Reinhoudt, D. N. J. Am. Chem. Soc. 2002, 124, 10754–10758. (g) Karinaga, R.; Jeong, Y.; Shinkai, S.; Kaneko, K.; Sakurai, K. Langmuir 2005, 21, 9398–9401. (10) (a) Cui, J.; Zheng, J.; Qiao, W.; Wan, X. H. J. Colloid Interface Sci. 2008, 326, 267–274. (b) Zheng, J.; Qiao, W.; Wan, X. H.; Gao, J. P.; Wang, Z. Y. Chem. Mater. 2008, 20, 6163–6168. (c) Cui, J.; Shen, Z.; Wan, X. H. Langmuir 2010, 26, 97–103. (d) Cui, J.; Liu, A.; Guan, Y.; Zheng, J.; Shen, Z.; Wan, X. H. Langmuir 2010, 26, 3615– 3622. (11) (a) Hafkamp, R. J. H.; Kokke, B. P. A.; Danke, I. M.; Geurts, H. P. M.; Rowan, A. E.; Feiters, M. C.; Nolte, R. J. M. Chem. Commun. 1997, 545–546. (b) Ghosh, R.; Chakraborty, A.; Maiti, D. K.; Puranik, V. G. Org. Lett. 2006, 8, 1061–1064. (c) Wang, G.; Cheuk, S.; Yang, H.; Goyal, N.; Reddy, P. V. N.; Hopkinson, B. Langmuir 2009, 25, 8696–8705. (12) (a) Oda, R.; Huc, I.; Candau, S. J. Angew. Chem., Int. Ed. 1998, 37, 2689– 2691. (b) Oda, R.; Huc, I.; Schmutz, M.; Candau, S. J.; MacKintosh, F. C. Nature 1999, 399, 566–569. (c) Berthier, D.; Buffeteau, T.; L eger, J. M.; Oda, R.; Huc, I. J. Am. Chem. Soc. 2002, 124, 13486–13494. (13) Oda, R. In Molecular Gels: Materials with Self-Assembled Fibrillar Net- works; Weiss, R. G., Terech, P., Eds.; Springer: Dordrecht, The Netherlands, 2005; pp 577-612. (14) (a) Engelkamp, H.; Middelbeek, S.; Nolte, R. J. M. Science 1999, 284, 785– 788. (b) Hill, J. P.; Jin, W.; Kosaka, A.; Fukushima, T.; Ichihara, H.; Shimomura, T.; Ito, K.; Hashizume, T.; Ishii, N.; Aida, T. Science 2004, 304, 1481–1483. (c) Hirst, A. R.; Smith, D. K. In Topics in Current Chemistry; Springer-Verlag: New York, 2005; Vol. 256, pp 237-273. (d) Hanabusa, K.; Fukui, H.; Suzuki, M.; Shirai, H. Langmuir 2005, 21, 10383–10390. (e) Yoshida, M.; Koumura, N.; Misawa, Y.; Tamaoki, N.; Matsumoto, H.; Kawanami, H.; Kazaoui, S.; Minami, N. J. Am. Chem. Soc. 2007, 129, 11039– 11041. (f) Huang, X.; Weiss, R. G. Tetrahedron 2007, 7375–7385. (g) Kundu, S. K.; Osaka, N.; Matsunaga, T.; Yoshida, M.; Shibayama, M. J. Phys. Chem. B 2008, 112, 16469–16477. (15) (a) Liu, X. Y. In Topics in Current Chemistry; Springer-Verlag: New York, 2005; Vol. 256, pp 1-37.(b) Tanaka, F. In Molecular Gels: Materials with Self- Assembled Fibrillar Networks; Weiss, R. G., Terech, P., Eds.; Springer: Dordrecht, The Netherlands, 2005; pp 17-78.