Knowledge Bank

Infrared spectra of the fundamental band of OH+ and the $\nu s$ band of $H2O+$ have been observed in an a.c. glow discharge of a $He/H2/O2(100:1:1)$ gas mixture. A laser difference frequency spectrometer and velocity modulation were used for the detection. The intensity of the transitions indicates OH+ and $H2O+$ concentrations of $\sim 5\times 109cm-3$, with an $H3O+$ abundance of the same order. The observed spectrum of OH+ has enabled us to improve the accuracy of the molecular constants reported by Merer et. $al1$. For the $\nu 3$ band of $H2O+$, eight pairs of combination differences in the ground state were used together with the previous data of $Lew2$ to determine improved ground state constants. The molecular constants in the (0,0,1) state were determined for the first time.