A new ion-pair state of iodine chloride

A previously-unknown ion-pair state of ICl has been identified and characterized in sequential transitions using polarization-labelling spectroscopy. This state is designated 1(3P1), indicating a state of axial electronic angular momentum Ω = 1 correlating diabatically at dissociation with the states I+(3P1) + Cl−(1S0) of the separated ions. The electronic energy and local potential constants for levels with ν = 1–7 are (in cm−1) Tc = 45552.805(23), ωc = 184.854(13), ωcxc = 0.6737(13), Bc = 0.058898(42), and α = 2.485(93) × 10−4, and the equilibrium bond distance is 3.231 A.