1 Halogen-Bond Driven Self-Assembly of Triangular Macrocycles Patrick M. J. Szell, a Antti Siiskonen, b Luca Catalano, c Gabriella Cavallo,* ,c Giancarlo Terraneo, c Arri Priimagi, b David L. Bryce a and Pierangelo Metrangolo* ,c a Department of Chemistry and Biomolecular Sciences, University of Ottawa, 10 Marie Curie Private, Ottawa, Ontario K1N 6N5, Canada b Laboratory of Chemistry and Bioengineering, Tampere University of Technology, P.O.Box 541, FI-33101 Tampere, Finland. c Laboratory of Supramolecular and BioNano Materials (SupraBioNanoLab), Department of Chemistry, Materials, and Chemical Engineering “Giulio Natta”, Politecnico di Milano, Via Luigi Mancinelli 7, Milano I-20131, Italy. Electronic Supplementary Information Electronic Supplementary Material (ESI) for New Journal of Chemistry. This journal is © The Royal Society of Chemistry and the Centre National de la Recherche Scientifique 2018