3.2.2 | Interaction Energies
There are five different types of intermolecular noncovalent
interactions in the six diiodoalkene dimers (see Figure 4): I…I,
I…O, I…C(π), I…H and O…O. Interaction energy
is an importantmeasure of the strength of an intermolecular interaction.
The interaction energy in the dimers can be regarded as the energy
difference between the dimer and the monomers as captured via Eq. (1).
Table 4 summarizes the interaction energies of the halogen bonds in the
six dimers. All results were corrected for BSSE by using counterpoise
methods. Naturally, the effect of BSSE correction is prominent for
halogen bonds. Calculations are carried out for crystal and optimized
dimers, respectively, to explore whether if it is necessary to optimize
the crystal structure geometries.