Tuning of halogen-bond strength: Comparative role of basicity and strength of σ-hole

Abstract A theoretical study has been carried out on the N...Clhalogen bonded complexes between various halomethanes and ammonia derivatives at the MP2=Full/aug-cc-pVTZ level. The binding energy of these complexes is found to correlate well with the positive electrostatic potential (Vmax) on the Cl atom and the proton affinityof the N-bases. The comparative role of Vmax on Cl atom and the proton affinity of N-bases in stabilizing the halogen bonded complexes are explored. Strength of the σ−hole is more important in determining the electrostatic interaction energy than the basicity of electron donor.