Algar, J.L.Phillips, J.E.Evans, J.D.Preston, D.2023-09-182023-09-182023Chemistry: An Asian Journal, 2023; 18(20):e202300673-1-e202300673-71861-471X1861-471Xhttps://hdl.handle.net/2440/139485Version of record online: September 11, 2023We report flexible [Pd(L)2 ]2+ complexes where there is self-recognition, driven by π-π interactions between electron-rich aromatic arms and the cationic regions they are tethered to. This self-recognition hampers the association of these molecules with aromatic molecular targets in solution. In one case, this complex can be reversibly converted to an 'open' [Pd2 (L)2 ]4+ macrocycle through introduction of more metal ion. This is accomplished by the ligand having two bidentate binding sites: a 2-pyridyl-1,2,3-triazole site, and a bis-1,2,3-triazole site. Due to favourable hydrogen bonding, the 2-pyridyl-1,2,3-triazole units reliably coordinate in the [Pd(L)2 ]2+ complex to control speciation: a second equivalent of Pd(II) is required to enforce coordination to bis-triazole sites and form the macrocycle. The macrocycle interacts with a molecular substrate with higher affinity. In this fashion we are able to use stoichiometry to reversibly switch between two different species and regulate guest binding.en© 2023 The Authors. Chemistry - An Asian Journal published by Wiley-VCH GmbH. This is an open access article under the terms of the Creative Commons Attribution Non-Commercial License, which permits use, distribution and reproduction in any medium, provided the original work is properly cited and is not used for commercial purposes.self-assemblymetallo-supramolecularpalladium(II)host-guest chemistrystructural transformationJournal article10.1002/asia.2023006732023-09-18655847Evans, J.D. [0000-0001-9521-2601]