Organometallic trimacrocyclic hexasubstituted benzenes: Synthesis, structure and properties

Macrocyclization proves a useful strategy for obtaining artificial supramolecular hosts via reducing the degrees of freedom of the corresponding precursors. However, synthesis of receptor containing multiple macrocycles is challenging. In this contribution, we describe the rational design and synthesis of a new class of organometallic trimacrocyclic hexasubstituted benzenes 1 and 2 via either metal–ligand coordination or dynamic covalent chemistry strategies. Such class of constructs feature a benzene core fused by three identical metallomacrocycles with high symmetry and interesting physiochemical property, as inferred from the NMR, mass spectrometry, cyclic voltammetry and DFT calculations. Trimacrocycle 2 bearing one ferrocene unit in each sub–macrocycle was found able to selectively capture bromide and iodide, as evidenced by NMR spectroscopy, DFT calculations, as well as molecular dynamics simulations. Thus, we hope this study will somewhat accelerate the development of complex functional host–guest systems for species of interest.