On the activation of PhICl₂ with pyridine

It has been previously proposed that pyridines can activate PhICl₂ by displacing a chloride and forming the [PhI(Pyr)(Cl)]⁺ cation as a reactive intermediate. Here we show that pyridine does not displace chloride, but rather forms a weak complex with the iodine via halogen bonding along the C-I bond axis. This interaction is interrogated by NMR, structural, charge density, and theoretical investigations, which all indicate that pyridine does not activate PhICl₂ as proposed.