2,3,4,5-Tetraiodopyrrole as a building block for halogen bonding: Formation of supramolecular hybrids with organic iodide salts in solid state

Abstract

Reactions of tri(n-propyl)ammonium (1) or 1,3,5-trimethylpyridinium (2) iodides with 2,3,4,5-tetraiodopyrrole (TIP) results in formation of hybrids CatI•TIP•xEtOH (X = 0.5 (1) and 0.33 (2), respectively) which feature strong halogen bonding (XB) between I atoms of TIP and iodide anions. DFT calculations reveal that XB energies are up to 4.3 kcal/mol.