DFT Workflow. Conformational searches were conducted on macrocycle geometries derived from the crystal structure of 1 using CREST (v. 2.11), followed by single point energies at the ωB97X-D3/def2-TZVP level of theory in ORCA (v. 5.0.3) for the forty lowest energy conformers. The lowest energy conformers following this re-ranking were used in all subsequent DFT calculations, where optimisations and frequency calculations were conducted at the SMD(Solvent)-ωB97X-D3/def2-QZVP// SMD(Solvent)-ωB97X-D3/def2-SVP level of theory (with diffuse basis sets on underlined atoms: I, Cl -and OH -), where the solvent corresponded to either DMSO (Figure ) or CHCl3 (Figure ).