The B←X electronic spectrum of N+2–Ne

Abstract

The electronic spectrum of N⁺₂–Ne has been measured in the region corresponding to the B ²∑⁺_u←X ²∑⁺_g origin and 1–0 transitions of N⁺₂. Spectra were obtained by irradiating a mass selected population of N⁺₂–Ne and monitoring the production of N⁺₂ as a function of wavelength. Low temperature N⁺₂–Ne spectra exhibit several well resolved bands. From the shift of the N⁺₂–Ne origin with respect to that of free N⁺₂ it is apparent that the complex dissociation energy D₀ is 146.5 cm⁻¹ greater in the B state than the X state. Pronounced changes in the complex’s spectrum occur as the effective temperature is increased. The hottest spectra resemble a broadened and truncated N⁺₂ spectrum. The breaking off at the high energy end of the spectrum at elevated temperatures allows us to establish a rough ground‐state dissociation energy of 300 cm⁻¹. Other conclusions resulting from this work are that the equilibrium geometry of the N⁺₂–Ne molecule is probably linear in X and B electronic states, that the ΔG_1/2 for the low frequency stretch in the B state is 104 cm⁻¹, and that the N–N stretching motion is affected only very weakly by the presence of the Ne atom.