Charge-Transfer Complexes between Dihalogen Compounds and Electron Donors

Abstract

A theoretical study of the charge-transfer complexes formed by dihalogen compounds (F2, Cl2, Br2, FBr, FCl, and ClBr) and electron donors (FH, OH2, NH3, CO, NCH, and C2H2) has been carried out. The geometries, energies, and electronic and spectroscopic properties of these complexes have been compared with the corresponding properties of the hydrogen bonded complexes of FH with the same electron donors. The hybrid HF-DFT, B3LYP, and second-order Møllet−Plesset perturbation, MP2, methods have been used. The properties analyzed include geometry, energy, electron distribution using the atoms in molecules (AIM) methodology, and spectroscopic constants of the complexes and monomers. Similarities in the variations of the geometries, in the trends in the interaction energetic, and in the topological electron density characteristics between the properties of the HB complexes and the dihalogen charge-transfer systems are pointed out. The main differences correspond to the variation trend of the atomic properties and the NMR shielding when going from the monomers to the complexes.

The Diiodine Basicity Scale: Toward a General Halogen‐Bond Basicity Scale

“…This conclusion, drawn from experimental DG values, is supported by computed interaction energies for many other inorganic XY. Thus, F 2 , Cl 2 , Br 2 , BrCl, ClF and BrF rank six very diverse bases (FH, H 2 O, NH 3 , CO, HC N and HC CH) in the same order of strength, [91] as shown by the correlation matrix of Table 12. Moreover, the interaction energies [92] of 45 82 CpNi…”

Review on DFT and ab initio Calculations of Scalar Coupling Constants

“…For instance, other interactions deserved to be explored like inverse HBs [51,52], three-centered (bifurcated) HBs [53], charge-transfer bonds [54], etc. One of the main objectives that should be approached in the next years is the calculation of coupling constants including heavy atoms (therefore, including relativistic corrections) because the structure of many fundamental problems in chemistry (catalysis) and biochemistry involve these atoms.…”

Halogen Bonding: An AIM Analysis of the Weak Interactions

“…so-called halogen bonding (XB), play pivotal roles in the fields of molecular recognition, [1][2][3][4][5] crystal engineering, [6][7][8] and possibly in biological systems. 9,10 Numerous theoretical efforts have been made on the halogen-bonded complexes toward understanding the nature of halogen bonding, [11][12][13][14][15][16] although they are far fewer than those for hydrogen bonding.…”