The relative strength and role in crystal packing of I−⋯π and CH⋯I− interactions in iminium salts

The relative energy and importance of Hal−⋯π and CH⋯Hal− interactions were studied basing on the crystal structures of iminium salts with different I⋯C distances. DFT calculations of the corresponding cations and ionic pairs were performed in an isolated state, accompanied by PW-DFT calculations of the crystals. The QTAIM methods in conjunction with the Espinosa–Lecomte correlation scheme were used to estimate the energies of C⋯I and H⋯I interactions both in isolated and in solid state. A detailed CSD survey was performed to estimate the relative abundance of these interactions in iminium salts.