The lifetimes of 108 different rotational levels of the OH A state (υ = 0-2) have been measured at high spectral resolution using the High Frequency Deflection technique. From these lifetimes the variation of the electronic transition moment is deduced as well as the predissociation rates for levels above the dissociation limit and the formation rate of OH through inverse predissociation.

Radiative lifetimes of the A 2Σ+, B 2Π, B' 2Δ, C 2Π, D 2Σ+ and F 2Δ electronic states in NO have been measured at high spectral resolution using the High Frequency Deflection technique. Particular attention has been paid to levels in the vicinity of or above the first dissociation limit in order to search for predissociation effects. The well-known effect in the C state is confirmed, while new predissociations of the A and D states and their rates are established. An anomaly in the lifetime series (B', v = 0-5) at v = 4 is explained in terms of the B'(v = 4) ∼ F(v = 1) configuration interaction. The variation in the A-X transition moment has been measured and found to be substantially different from earlier estimates.

The spectra of NH+, OH+ and SH+ in the range 3 000-5 000 Å have been studied at 0.2-0.4 Å FWHM resolution using the High-Frequency Deflection technique. Radiative lifetimes of low-lying excited electronic states in these molecules were simultaneously measured and found to be of the magnitude of 400-1 100 ns.