Interaction of bihalogen anions with nitrogen: Matrix-isolation study and first principle calculations of the (ClHCl)−⋯N2 and (BrHBr)−⋯N2 complexes

The N2 complexes of (ClHCl)− and (BrHBr)− are studied both experimentally using IR absorption spectroscopy and computationally. Two computational [MP2(full)/6-311++G(2d,2p)] geometries for the systems were found, and the cross-like structure is energetically the more stable for both of the systems. The BSSE-corrected interaction energies for the cross-like structures are −500 to −600 cm−1. The matrix-isolation experiments support the formation of this complex structure, and the experimental complexation-induced shift is +4.8 and +7.1 cm−1 for the (ClHCl)−⋯N2 and (BrHBr)−⋯N2 complexes, respectively. The HArCl and HKrBr molecules do not appear upon annealing of the photolyzed HCl/Ar and HBr/Kr matrices probably suggesting instability of these molecules.