Strength of the NF(b1Σ+→X3Σ−) transition. II. Estimate of the NF ground state dissociation limit by analysis of the Δv=0 emission sequence

The Δv=0 sequence of the NF(b1Σ+v′→X3Σ−v″) spin forbidden emission is studied from the intensity point of view. The NF b1Σ+ emitting state is produced by NF3 windowless photolysis in a microwave flowing afterglow apparatus. Although the observed NF b1Σ+ vibrational population is at a Boltzmann equilibrium, v′=1 through v′=3 emitting levels appear to be depleted. This behaviour is attributed to interactions of the emitting b1Σ+ state with the ground state continuum. A value of 60.7±1.5 kcal/mol for the NF X3Σ− dissociation limit is thus estimated.