Compound model-morphed potentials contrasting OC-79Br35Cl with the halogen bonded OC-35Cl2 and hydrogen-bonded OC-HX (X = 19F, 35Cl, 79Br)

•Rovibrational spectroscopy of halogen bonded OC-BrCl in supersonic jet at 4.6 μm.•5-Dimensional morphed potential produced for halogen bond with large dipole moment.•Equilibrium structure of OC-BrCl complex investigated based on morphed potential.•Analysis of intermolecular dynamics in OC-BrCl relative to hydrogen bonded OC-HF.•Correlation of series OC-Cl2, OC-BrCl and OC-Br2 with Badger-Bauer type rule.

A five-dimensional compound-model morphed (CMM) potential has been generated for the halogen bonded intermolecular interaction 16O12C-79Br35Cl based on a fit to the currently generated infrared and previously available microwave spectroscopic data. The experimentally determined blue frequency shift of the 16O12C stretching frequency on complexation with 79Br35Cl is found to be Δν = 12.89643(28) cm−1 indicating a more strongly bound complex than in OC-35Cl2. Re center-of-mass to center-of-mass distance of 4.270(7) Å and dissociation energies De = 778(70) cm−1 and D0 = 605(70) cm−1 are predicted from the CMM potential and also compared with the corresponding values of Re = 4.742(3) Å and De = 544(5) cm−1 and D0 = 397(5) cm−1 for 16O12C-35Cl2. The molecular dynamics, binding energy and other molecular parameters of OC-BrCl are also compared with the hydrogen bonded dimers OC-HX (X = F, Cl, Br) giving further insight into the characteristics of the complex.

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