Terpyridine as a Ligand for Halogen Species: A Theoretical Assessment of the Complexation Ability

Complex formation between diatomic halogens(interhalogens) and 2,2:6,2-terpyridine was computationally studied at M06-2X/def2-TZVP level of theory. Relaxed potential energy scans were performed to identify preliminary minima on the potential energy surfaces for the molecular complexes of 1 : 1, 2 : 1 and 3 : 1 composition, followed by geometry optimization without constraints. Obtained results indicate that the stability of molecular complexes decreases in order 1 : 1 > 2 : 1 > 3 : 1, and all complexes, with the exception of ICl, are thermodynamically unstable both in the gas phase and in the nonpolar solvent CCl4 already at room temperature.