Theoretical study of halogen–hydride halogen bonds in F₃CL ··· HM (L=Cl, Br; M=Li, BeH, MgH) complexes

Abstract

Quantum chemical calculations have been performed on six halogen–hydride halogen bonded complexes with F₃CCl or F₃CBr as the halogen donor and metal hydride (HLi, HBeH and HMgH) as the halogen acceptor. At the MP2/6-311++G(d,p) level, the interaction strength spans from 2.62 to 17.68 kJ mol^–1. The C–Cl and C–Br bonds are contracted. However, no evident blue shift accompanies this contraction. The H–Li bond is also contracted, but the H–He and H–Mg bonds are lengthened. However, a blue shift occurs for all these bond-stretching vibrations. These properties were analysed using the theory of natural bond orbital (NBO) and atoms in molecules (AIM). A symmetry-adapted perturbation theory (SAPT) analysis was also carried out to unveil the nature of this novel interaction. It is demonstrated that the electrostatic interaction plays a main role in the interaction, although induction and dispersion interactions are also important.

Keywords:

• halogen–hydride halogen bond
• blue shift
• dihydrogen bond
• σ–hole interaction
• symmetry-adapted perturbation theory

Acknowledgements

This work was supported by the National Natural Science Foundation of China (Grant No. 20973149). It was also supported, in part, by an open project of the State Key Laboratory of Supramolecular Structure and Materials (SKLSSM200909), Jilin University, China.