Theoretical study of halogen bonding between FnH3-nCBr (n=0, 1, 2, 3) and HMgH

In this work, ab initio Calculations have been performed to investigate the interaction between FnH3-nCBr (n = 0, 1, 2, 3) and HMgH at the MP2/aug-cc-pVTZ level. The results obtained from these calculations reveal the weak non-covalent Br center dot center dot center dot H interactions in all complexes. The calculated interaction energies for the complexes span from -2.17 to -8.98 kJ/mol. Upon complexation, the C-Br and H-Mg bonds are both elongated. Most C-Br stretches have a small red shift, whereas the H-Mg stretch exhibits a blue shift. These complexes are stabilized by the electrostatic interaction, charge transfer interaction and polarization interaction. The halogen-bonding nature of the Br center dot center dot center dot H interactions has been identified in terms of the bond critical point analysis within the theory of atoms in molecules. (C) 2009 Elsevier B.V. All rights reserved.