ROTATIONAL ANALYSIS OF AN ELECTRONIC TRANSITION OF CuOH OBSERVED WITH INTRACAVITY LASER SPECTROSCOPY

An electronic transition of CuOH has been observed in the red using Intracavity Laser Spectroscopy (ILS). The CuOH molecules were produced in the 0.60 A RF-discharge of a Cu hollow cathode using either 1 Torr of H$_{2}$ and 200 mTorr of O$_{2}$ as sputter gases to produce CuOH, or 800 mTorr of O$_{2}$ and 200 mTorr of D$_{2}$ to produce CuOD. The hollow cathode was located in the resonator cavity of a dye laser, enabling the enhancement of molecular absorption features through laser action. Using a generation time of 200 $\mu$sec and a 130 mm long cathode, the effective pathlength for the measurements was approximately 7 km. Each 6 \wn wide spectral segment was calibrated by fitting I$_{2}$ absorbance features from spectra collected from an extracavity I$_{2}$ cell at each monochromator position (with the plasma turned off) to the I$_{2}$ reference data of Salami and Ross. Deviations between the recorded and reference I$_{2}$ features were typically less than $\pm$0.002 \wn. Two strong red-degraded Q-bandheads are observed in the CuOH spectrum, located at 15,155 \wn and 15,093 \wn. These bands are consistent with an electronic transition briefly mentioned but not analyzed in a publication on the \textit{A} $^{1}$A'-\textit{X} $^{1}$A' transition of CuOH by Jarman \textit{et al}. from 1991. The isotopologue shifts of the CuOD Q-heads are +4.5 \wn and +5.0 \wn, respectively. The transitions for both isotopologues have P-, Q-, and R-branches with no observed splitting. Each branch is accompanied by features due to $^{65}$CuOH that are approximately 40\% of the intensity of the main features, consistent with natural abundances of 69.17\% $^{63}$Cu and 30.83\% $^{65}$Cu. Ground state constants for CuOH and CuOD are determined from the millimeter wave spectra of Whitham \textit{et al}., and the transitions will be fit using PGOPHER. Results of the analysis will be presented