Supramolecular gels are topical soft materials involving the reversible formation of fibrous aggregates using non-covalent interactions. There is significant interest in controlling the properties of such materials by the formation of multicomponent systems, which exhibit non-additive properties emerging from interaction of the components. The use of hydrogen bonding to assemble supramolecular gels in organic solvents is well established. In contrast, the use of halogen bonding to trigger supramolecular gel formation in a two-component gel (‘co-gel’) is essentially unexplored, and forms the basis for this study. Here, we show that halogen bonding between a pyridyl substituent in a bis(pyridyl urea) and 1,4-diiodotetrafluorobenzene brings about gelation, even in polar media such as aqueous methanol and aqueous dimethylsulfoxide. This demonstrates that halogen bonding is sufficiently strong to interfere with competing gel-inhibitory interactions and create a ‘tipping point’ in gel assembly. Using this concept, we have prepared a halogen bond donor bis(urea) gelator that forms co-gels with halogen bond acceptors.
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Smith, D. K. in Organic Nanostructures (eds Atwood, J. L. & Steedin, J. W.) 111–154 (Wiley-VCH, 2008).
Hirst, A. R., Escuder, B., Miravet, J. F. & Smith, D. K. High-tech applications of self-assembling supramolecular nanostructured gel-phase materials: from regenerative medicine to electronic devices. Angew. Chem. Int. Ed. 47, 8002–8018 (2008).
Foster, J. A. et al. Supramolecular gels: anion-switchable media for controlling crystal growth. Nature Chem. 2, 1037–1043 (2010).
Li, H., Fujiki, Y., Sada, K. & Estroff, L. A. Gel incorporation inside of organic single crystals grown in agarose hydrogels. CrystEngComm 13, 1060–1062 (2011).
Estroff, L. A. & Hamilton, A. D. Water gelation by small organic molecules. Chem. Rev. 104, 1201–1217 (2004).
Estroff, L. A., Addadi, L., Weiner, S. & Hamilton, A. D. An organic hydrogel as a matrix for the growth of calcite crystals. Org. Biomol. Chem. 2, 137–141 (2004).
Van Bommel, K. J. C., Stuart, M. C. A., Feringa, B. L. & van Esch, J. Two-stage enzyme mediated drug release from LMWG hydrogels. Org. Biomol. Chem. 3, 2917–2920 (2005).
Yang, Z. et al. Self-assembly of small molecules affords multifunctional supramolecular hydrogels for topically treating simulated uranium wounds. Chem. Commun. 4414–4416 (2005).
Escuder, B., Rodríguez-Llansola, F. & Miravet, J. F. Supramolecular gels as active media for organic reactions and catalysis. New J. Chem. 34, 1044–1054 (2010).
Terech, P. & Weiss, R. G. Low molecular mass gelators of organic liquids and the properties of their gels. Chem. Rev. 97, 3133–3160 (1997).
Dastidar, P. Supramolecular gelling agents: can they be designed? Chem. Soc. Rev. 37, 2699–2715 (2008).
Fages, F. Metal coordination to assist molecular gelation. Angew. Chem. Int. Ed. 45, 1680–1682 (2006).
Foster, J. A. & Steed, J. W. Exploiting cavities in supramolecular gels. Angew. Chem. Int. Ed. 49, 6718–6724 (2010).
Maeda, H. Anion-responsive supramolecular gels. Chem. Eur. J. 14, 11274–11282 (2008).
Steed, J. W. Supramolecular gel chemistry: developments over the last decade. Chem. Commun. 47, 1379–1383 (2011).
Rodríguez-Llansola, F., Escuder, B. & Miravet, J. F. Switchable perfomance of an l-proline-derived basic catalyst controlled by supramolecular gelation. J. Am. Chem. Soc. 131, 11478–11484 (2009).
Yang, H. et al. Switchable fluorescent organogels and mesomorphic superstructure based on naphthalene derivatives. Langmuir 23, 8224–8230 (2007).
Hsueh, S-Y. et al. Acid/base- and anion-controllable organogels formed from a urea-based molecular switch. Angew. Chem. Int. Ed. 49, 9170–9173 (2010).
Zhang, S. Y. et al. Ultrasound-induced switching of sheetlike coordination polymer microparticles to nanofibers capable of gelating solvents. J. Am. Chem. Soc. 131, 1689–1691 (2009).
Dutta, S., Shome, A., Debnath, S. & Das, P. K. Counterion dependent hydrogelation of amino acid based amphiphiles: switching from non-gelators to gelators and facile synthesis of silver nanoparticles. Soft Matter 5, 1607–1620 (2009).
Peng, F., Li, G., Liu, X., Wu, S. & Tong, Z. Redox-responsive gel–sol/sol–gel transition in poly(acrylic acid) aqueous solution containing Fe(III) ions switched by light. J. Am. Chem. Soc. 130, 16166–16167 (2008).
Cravotto, G. & Cintas, P. Molecular self-assembly and patterning induced by sound waves. The case of gelation. Chem. Soc. Rev. 38, 2684–2697 (2009).
Naota, T. & Koori, H. Molecules that assemble by sound: an application to the instant gelation of stable organic fluids. J. Am. Chem. Soc. 127, 9324–9325 (2005).
Steed, J. W. Anion-tuned supramolecular gels: a natural evolution from urea supramolecular chemistry. Chem. Soc. Rev. 39, 3686–3699 (2010).
Piepenbrock, M. O. M., Lloyd, G. O., Clarke, N. & Steed, J. L. Metal- and anion-binding supramolecular gels. Chem. Rev. 110, 1960–2004 (2010).
Becker, T. et al. Proline-functionalised calixarene: an anion-triggered hydrogelator. Chem. Commun. 3900–3902 (2008).
Shen, J-S., Cai, Q-G., Jiang, Y-B. & Zhang, H-W. Anion-triggered melamine based self-assembly and hydrogel. Chem. Commun. 46, 6786–6788 (2010).
Lloyd, G. O. & Steed, J. W. Anion-tuning of supramolecular gel properties. Nature Chem. 1, 437–442 (2009).
Piepenbrock, M-O. M., Lloyd, G. O., Clarke, N. & Steed, J. W. Gelation is crucially dependent on functional group orientation and may be tuned by anion binding. Chem. Commun. 2644–2646 (2008).
Lloyd, G. O., Piepenbrock, M-O. M., Foster, J. A., Clarke, N. & Steed, J. W. Anion tuning of chiral bis(urea) low molecular weight gels. Soft Matter 8, 204–216 (2012).
Piepenbrock, M-O. M., Clarke, N., Foster, J. A. & Steed, J. W. Anion tuning and polymer templating in a simple low molecular weight organogelator. Chem. Commun. 47, 2095–2097 (2011).
Byrne, P. et al. Metal-induced gelation in dipyridyl ureas. New J. Chem. 34, 2261–2274 (2010).
Piepenbrock, M-O. M., Clarke, N. & Steed, J. W. Shear-induced gelation in a copper(II) metallogel: new aspects of ion-tunable rheology and gel-reformation by external chemical stimuli. Soft Matter 6, 3541–3547 (2010).
Piepenbrock, M-O. M., Clarke, N. & Steed, J. W. Metal ion and anion based ‘tuning’ of a supramolecular metallogel. Langmuir 25, 8451–8456 (2009).
Biradha, K., Su, C-Y. & Vittal, J. J. Recent developments in crystal engineering. Cryst. Growth Des. 11, 875–886 (2011).
Saha, B. K., Nangia, A. & Jaskolski, M. Crystal engineering with hydrogen bonds and halogen bonds. CrystEngComm 7, 355–358 (2005).
Braga, D., Brammer, L. & Champness, N. R. New trends in crystal engineering. CrystEngComm 7, 1–19 (2005).
Metrangolo, P., Meyer, F., Pilati, T., Resnati, G. & Terraneo, G. Halogen bonding in supramolecular chemistry. Angew. Chem. Int. Ed. 47, 6114–6127 (2008).
Metrangolo, P., Meyer, F., Pilati, T., Proserpio, D. M. & Resnati, G. Highly interpenetrated supramolecular networks supported by N···I halogen bonding. Chem. Eur. J. 13, 5765–5772 (2007).
Metrangolo, P., Neukirch, H., Pilati, T. & Resnati, G. Halogen bonding based recognition processes: a world parallel to hydrogen bonding. Acc. Chem. Res. 38, 386–395 (2005).
Metrangolo, P. & Resnati, G. in Encyclopedia of Supramolecular Chemistry Vol. 1 (eds Atwood, J. L. & Steed, J. W.) 628–635 (Marcel Dekker, 2004).
Yan, D. et al. A cocrystal strategy to tune the luminescent properties of stilbene-type organic solid-state materials. Angew. Chem. Int. Ed. 50, 12483–12486 (2011).
Cavallo, G. et al. Halogen bonding: a general route in anion recognition and coordination. Chem. Soc. Rev. 39, 3772–3783 (2010).
Aakeröy, C. B., Chopade, P. D. & Desper, J. Avoiding ‘synthon crossover’ in crystal engineering with halogen bonds and hydrogen bonds. Cryst. Growth Des. 11, 5333–5336 (2011).
Aakeröy, C. B., Chopade, P. D., Ganser, C. & Desper, J. Facile synthesis and supramolecular chemistry of hydrogen bond/halogen bond-driven multi-tasking tectons. Chem. Commun. 47, 4688–4690 (2011).
Ryan, D. M., Doran, T. M. & Nilsson, B. L. Complementary π–π interactions induce multicomponent coassembly into functional fibrils. Langmuir 27, 11145–11156 (2011).
Adarsh, N. N., Kumar, D. K. & Dastidar, P. Composites of N,N′-bis-(pyridyl) urea-dicarboxylic acid as new hydrogelators—a crystal engineering approach. Tetrahedron 63, 7386–7396 (2007).
Moffat, J. R. & Smith, D. K. Controlled self-sorting in the assembly of multi-gelator gels. Chem. Commun. 316–318 (2009).
Byrne, P., Turner, D. R., Lloyd, G. O., Clarke, N. & Steed, J. W. Gradual transition from NH···pyridyl hydrogen bonding to the NH···O tape synthon in pyridyl ureas. Cryst. Growth Des. 8, 3335–3344 (2008).
Todd, A. M., Anderson, K. M., Byrne, P., Goeta, A. E. & Steed, J. W. Helical or polar guest-dependent z′=1.5 or z′=2 forms of a sterically hindered bis(urea) clathrate. Cryst. Growth Des. 6, 1750–1752 (2006).
Ostuni, E., Kamaras, P. & Weiss, R. G. Novel X-ray method for in situ determination of gelator strand structure: polymorphism of cholesteryl anthraquinone-2-carboxylate. Angew. Chem. Int. Ed. Engl. 35, 1324–1326 (1996).
George, M., Tan, G., John, V. T. & Weiss, R. G. Urea and thiourea derivatives as low molecular-mass organogelators. Chem. Eur. J. 11, 3243–3254 (2005).
Anderson, K. M. et al. Structure calculation of an elastic hydrogel from sonication of rigid small molecule components. Angew. Chem. Int. Ed. 47, 1058–1062 (2008).
Henry, M. Thermodynamics of hydrogen bond patterns in supramolecular assemblies of water molecules. ChemPhysChem 3, 607–616 (2002).
Henry, M. Nonempirical quantification of molecular interactions in supramolecular assemblies. ChemPhysChem 3, 561–569 (2002).
Walsh, R. B. et al. Crystal engineering through halogen bonding: complexes of nitrogen heterocycles with organic iodides. Cryst. Growth Des. 1, 165–175 (2001).
Wenk, H. H. & Sander, W. 2,3,5,6-Tetrafluorophenylnitren-4-yl: a quartet-ground-state nitrene radical. Angew. Chem. Int. Ed. 41, 2742–2745 (2002).
J.W.S., K.F. and J.A.F. acknowledge funding from the Engineering and Physical Sciences Research Council and GlaxoSmithKline. P.M. and G.R. thank Fondazione Cariplo (project nos 2009-2550 and 2010-1351) for financial support.
The authors declare no competing financial interests.
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Meazza, L., Foster, J., Fucke, K. et al. Halogen-bonding-triggered supramolecular gel formation. Nature Chem 5, 42–47 (2013). https://doi.org/10.1038/nchem.1496
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