Since its discovery, supramolecular chemistry has completely revolutionized the concept of molecular chemistry, allowing for manipulation and production of larger assemblies based on molecular components held together by noncovalent interactions. The great simplicity of this bottom-up approach has been successfully exploited for the construction of sophisticated systems impacting several fields, including organic electronics, nanotechnology, biology, medicine and materials science. Exploring novel, specific noncovalent interactions underlying an intermolecular recognition process may open up new perspectives in controlling physical and chemical properties of bulk materials. At the SBNLab we are interested in the development of new functional materials self-assembled through halogen bonding (XB), the noncovalent interaction involving halogen atoms as electrophilic species. In particular we have applied XB in the design of new liquid crystalline materials starting from nonmesomorphic components and developed high-performance photoresponsive polymers and liquid crystals.[1-3] Moreover, we have demonstrated that XB plays a strong role in tuning the NLO properties of supramolecular systems, triggers the formation of supramolecular gels, and may be used for the realization of efficient transmembrane anion transporter.
1. R. Milani, N. Houbenov, F. Fernandez-palacio, G. Cavallo, A. Luzio, J. Haataja, G. Giancane, M. Saccone, A. Priimagi, Hierarchical Self-Assembly of HalogenBonded Block Copolymer Complexes into Upright Cylindrical Domains. Chem 2017, 2, 417.
2. G. Cavallo, G. Terraneo, A. Monfredini, M. Saccone, A. Priimagi, T. Pilati, G. Resnati, P. Metrangolo, D. W. Bruce, Superfluorinated ionic liquid crystals based on supramolecular, halogen-bonded anions. Angew. Chem. Int. Ed. 2016, 55, 6300.
3. Houbenov, R. Milani, M. Poutanen, J. Haataja, V. Dichiarante, J. Sainio, J. Ruokolainen, G. Resnati, P. Metrangolo, O. Ikkala, Halogen-bonded mesogens direct polymer self-assemblies up to millimetre length scale. Nature Commun. 2014, 5:4043, DOI: 10.1038/ncomms5043.
4. M. Virkki, O. Tuominen, A. Forni, M. Saccone, P. Metrangolo, G. Resnati, M. Kauranena, A. Priimagi, Halogen bonding enhances nonlinear optical response in poled supramolecular polymers. J. Mater. Chem. C 2015, 3, 3003.
5. A. Vargas Jentzsch, D. Emery, J. Mareda, S. K. Nayak, P. Metrangolo, G. Resnati, N. Sakai, S. Matile, Transmembrane anion transport mediated by halogen-bond donors. Nature Commun. 2012, 3:905, DOI:10.1038/ncomms1902.