Can the positive aromatic ring be as π-electron donor in π-halogen bond? A MP2 theoretical investigation on the unusual π-halogen bond interaction between three-membered ring (BNN)₃⁺ and X1X2 (X1, X2 = F, Cl, Br).
The unusual π-halogen bond interactions are investigated between (BNN)₃⁺ and X1X2 (X1, X2 = F, Cl, Br) employing MP2 at 6-311 + G(2d) and aug-cc-pVDZ levels according to the "CP (counterpoise) corrected potential energy surface (PES)" method. The order of the π-halogen bond interactions and stabilities of the complexes are obtained to be (BNN)₃⁺... F₂ < (BNN)₃⁺... ClF < (BNN)₃⁺... Cl₂ < (BNN)₃⁺... BrCl < (BNN)₃⁺... Br₂ < (BNN)₃⁺ ... BrF. at MP2/aug-cc-pVDZ level. The analyses of the Mulliken charge transfer, natural bond orbital (NBO), atoms in molecules (AIM) theory and electron density shifts reveal that the nature of the π-halogen bond interaction in the complexes of ClF, BrF and BrCl might partly be charge transfer from the delocalized π-HOMO orbital of (BNN)₃⁺ to X1X2. This result suggests that the positive aromatic ring (BNN)₃⁺ might act as a π-electron donor to form the π-halogen bond.
Qi
Hai-Tao
HT
College of Chemical Engineering and Environment, North University of China, Taiyuan 030051, China.
Ren
Fu-de
FD
Zhang
Jing-Lin
JL
Wang
Jing-Yu
JY
D001688:Biological Products / Q000138:chemical synthesis; D001895:Boron / Q000737:chemistry*; D004583:Electrons; D006219:Halogens / Q000737:chemistry*; D006841:Hydrocarbons, Aromatic / Q000737:chemistry*; D006860:Hydrogen Bonding; D008958:Models, Molecular; D009584:Nitrogen / Q000737:chemistry*; D019163:Reducing Agents / Q000737:chemistry; D055672:Static Electricity; D013816:Thermodynamics
D001688:Biological Products; D006219:Halogens; D006841:Hydrocarbons, Aromatic; D019163:Reducing Agents; D009584:Nitrogen; D001895:Boron