R ed-shiftin g and Blu e-shifting Halogen Bonds; a QTAIM Study

Generally, the formation of halogen bonds is always connected with the red-shiftingand blue shifting [۱]. In red-shifting the A-X bond in the complex A-X...N is longer and has a lower vibrational frequency than in isolated A-X. In blue-shifting the A-X bond length decreases and its vibrational frequency increases. In recent years, numerous studies devoted to finding the origin of A-X bond length changes in halogen bonded complexes. Wang and Hobza showed that although red-shifting is caused by charge transfer, in blue-shifting halogen bonds the charge transfer is only of minor importance and it is the electrostatic interactions that cause the A-X bond contraction [۲]. In the current work, we used atomic monopole and dipole moments, derived from quantum theory of atoms in molecules (QTAIM) [۳], to find differences between red-shifting and blue-shifting halogen bonds.

کلیدواژه ها:

Halogen Bond ، QTAIM ، Atomic Multipole Moment