LASER SPECTROSCOPY AND ROTATIONAL ANALYSIS OF THE A-X TRANSITIONS OF CaOH AND CaOD

Author Institution:CaOH and CaOD were formed in the gas phase by the reaction of $H_{2}O$ and $D_{2}O$ with Ca vapor entrained in a low pressure flow of argon. A single-mode ring dye laser was scanned through the $\Delta v = 0$ bands of the A-X system near 625.0 nm. The excitation spectra of CaOH and CaoD were recorded simultaneously with the excitation spectrum of molecular iodine. By measuring the P-R separation of the photoluminescence, we assigned about 140 individual rotational lines of the CaOH (000)-(000) band and about 40 lines of the CaOD (000)-(000) band. Using the molecular iodine lines as a reference, we determined the wavenumbers of those lines with an uncertainty of $\pm 0.01$ $cm^{-1}$. The spin-orbit parameter $A_{000}$ for CaOH is 65.96(2) $cm^{-1}$. Other detailed results and the molecular parameters determined by a least-squares fit to the observed lines will be presented at the conference. We also observed several lines which we attribute to the $A^{2} \Sigma - X^{2} \pi$ and $A^{2} \Delta - X^{2}\Pi$ vibronic transitions of the $(01^{1}0)-(01^{1}0)$ bands. From these observations, we tentatively determine that the Renner-Teller splitting of the $A(01^{1}0)$ state is 9.74(2) $cm^{-1}$ for CaOH and 4.53(2) $cm^{-1}$ for CaOD