Neutral halogen‐bonded O−I−N complexes were prepared from in situ formed carbonyl hypoiodites and aromatic organic bases. The carbonyl hypoiodites have a strongly polarized iodine atom with larger σ‐holes than any known uncharged halogen bond donor. Modulating the Lewis basicity of the selected pyridine derivatives and carboxylates leads to halogen‐bonded complexes where the classical O−I⋅⋅⋅N halogen bond transforms more into a halogen‐bonded COO⁻⋅⋅⋅I−N⁺ ion‐pair (salt) with an asymmetric O−I−N moiety. X‐ray analyses, NMR studies, and calculations reveal the halogen bonding geometries of the carbonyl hypoiodite‐based O−I−N complexes, confirming that in the solid‐state the iodine atom is much closer to the N‐atom of the pyridine derivatives than its original position at the carboxylate O‐atom.

New 1–2 nm macrocyclic iodine(I) complexes prepared VIA a simple ligand exchange reaction manifest rigid 0.5–1 nm cavities that bind the hexafluorophosphate anion in the gas phase. The size of the cavities and the electrostatic interactions with the iodine(I) cations influence the anion binding properties of these macrocyclic complexes.

Several neutral bis (O–I–N) compounds were synthesised incorporating various dihypoiodites and 4-ethylpyridine, which were characterised in both the solution and solid states.

The ligand exchange behavior among iodine( i ) complexes was comprehensively investigated via the stoichiometric combination of two homoleptic iodine( i ) complexes.