Mutual enhancing effects of the sigma-hole interactions and halogen/hydrogen-bonded interactions in the iodine-ylide containing complexes

摘要

The region of positive electrostatic potentials (sigma-hole) has been found along the extension of the C-I bond in the iodine-ylide CH2IH, which suggests that the iodine-ylide could interact with nucleophiles to form weak, directional noncovalent interactions. MP2 calculations confirmed that the I center dot center dot center dot N sigma-hole interaction exists in the CH2IH center dot center dot center dot NCX (X = H, F, Cl, Br, I) bimolecular complexes. The NCCl center dot center dot center dot CH2IH center dot center dot center dot NCX (X = H, F, Cl, Br, I) termolecular complexes were constructed to investigate the weakly bonded sigma-hole interactions to be strengthened by Cl center dot center dot center dot C halogen bond. And then, the NCY center dot center dot center dot CH2IH center dot center dot center dot NCCl (Y = H, F, Cl, Br, I) termolecular complexes were designed to investigate the enhancing effects of the I center dot center dot center dot N sigma-hole interaction on the Y center dot center dot center dot C halogen/hydrogen-bonded interactions. Accompany with the mutual enhancing processes of the sigma-hole interactions and halogen/hydrogen-bonded interactions in the iodine-ylide containing termolecular complexes, both the I center dot center dot center dot N sigma-hole interactions and Y center dot center dot center dot C halogen/hydrogen-bonded interactions become more polarizable.