(DL3DL_{3} LAST MINUTE ADDITION TO THE PROGRAM) Q BRANCHES OF THE ν2\nu_{2} BAND OF 13C16O17O, 13C17O2, 13C417O18O^{13}C^{16}O^{17}O,\ ^{13}C^{17}O_{2}, \ ^{13}C4^{17}O^{18}O AND 13C18O2^{13}C^{18}O_{2}

Author Institution:A diode laser has been employed to examine the Q branch absorption lines of the $\nu_{2}$ band for the following $CO_{2}$ isotopes: $^{13}C^{16}O^{17}O,\ ^{13}C^{17}O_{2}, \ ^{13}C4^{17}O^{18}O$ AND $^{13}C^{18}O_{2}$, and $^{13}C^{18}O_{2}$. An analysis of the relative frequency spacing between the absorption lines yielded the following values for $\Delta B$ expressed in units of $10^{-3}$ $cm^{-1}$: 1.016(2) for $^{13}C^{16}O^{17}O, 0.964(1)$ for $^{13}C^{17}O^{2}$, 0.9163(3) for $^{13}C^{17}O^{18} O$ and 0.891(2) for $^{13}C^{17}O_{2}$. Values for $\nu_{o}$, the band origin, were also obtained by super-imposing on the spectra known absorption lines of $^{12}C^{16}O_{2}$ and $^{12}C^{16}O^{18}O$. The following values were obtained for $\nu_{o}: 645.7440(2)$ for $^{13}C^{16}O^{17}O, 643.0064(1)$ for $^{13}C^{17}O_{2}, 640.5680(1)$ for $^{13}C^{17}O^{18}O$ and 638.1149(5) for $^{13}C^{18}O_{2}$. The above listed errors for $\nu_{o}$ are associated only with the statistical fitting of the data; the absolute accuracy depends upon the $^{12}C^{16}O_{2}$ reference lines which are known to about $\pm 0.001$ $cm^{-1}$. A comparison of the diode laser results are made with previous measurements utilizing Fourier transform spectroscopy

DIODE LASER SPECTROSCOPY OF Q-BRANCHES AT 662−661cm−1662-661 cm^{-1}, OF CO2CO_{2} ENCRICHED IN 18O^{18}O AND 17O^{17}O

Author Institution: Applied Photochemistry Division, Los Alamos Scientific Laboratory, University of California; Molecular Physics Building, Institute for Physical Science and Technology, University of MarylandMeasurements have been made of the absorption of the absorption of $CO_{2}$ samples enriched in 18O and 17O by tunable diode lasers in the wave number region 662.2-$666.1 cm^{-1}$. The fundamental Q-branches of the $^{16}O^{12}C^{18}O, ^{16}O^{12}C^{17}O$ and $^{17}O^{12}C^{17}O$ molecules are well resolved, together with ``hot’’ Q branches and various R and P branch lines of other isotopic species; notably $^{18}O^{12}C^{18}$ and $^{17}O^{12}C^{18}O$. The molecular constants for the Q-branch $01^{1}0 \leftarrow 00^{0}0$ of $^{16}O^{12}C^{18}O$ have been calculated by a least mean square fit to lines j=1 to 16 to be: $\nu_{o}=662.3717 \pm 0.0003\ cm^{-1}$, $\Delta B=9.65 + 0.02 \times 10^{-4} cm^{-1}$ where $\nu_{o}$ has been fixed in absolute magnitude by assuming the $^{16}O^{12}C^{16}O$ line, $02^{2}0 \leftarrow 01^{10}$ P7, as a reference standard at $662.325 cm^{-1}$. More accurate values for $\Delta B$ and $\Delta D$ can be obtained by using the separation between several R lines and adjacent Q lines, and the known positions of the R lines relative to the origin to obtain: $\Delta B=9.685 \pm 0.002 \times 10^{-4} cm^{-1}$ and $\Delta D=2.2 \pm 0.1 \times 10^{-9} cm^{-1}$. Other molecular constant can be determined with highest precision by using low J, R and P branch lines as calibration standards, together with etalon spacing. The calculated line positions of the fundamental Q branch can be used as secondary standards to fit the hot bands

DIRECT MEASUREMENT OF TWO 13C16O2^{13}C^{16}O_{2} Q-BRANCHES USING A 16 μ\mum TUNABLE DIODE LASER

Author Institution: Los Alamos Scientific Laboratory, University of CaliforniaTwenty-two spectral lines of the $^{13}C^{16}O_{2}$ Q-branch at $617 cm^{-1}$ have been observed, and fitted by a cubic polynomial in $J(J + 1)$ to a standard deviation of $\pm \ 3 \times 10^{-4}$ $cm^{-1}$. Another Q-branch, at $630.7 cm^{-1}$, has been observed for 12 lines, and fitted to a linear polynomial in $J(J + 1)$ to $\pm \ 9 \times 10^{-4} cm^{-1}$. The resulting molecular constants are given in Table I. [FIGURE] In addition, the positions of several lines from other isotopes and other bands have been measured with great accuracy relative to the adjacent lines of the above Q-branches

HIGH RESOLUTION SPECTRA OF SIXTEEN Q BRANCHES IN THE ν9\nu_{9} FUNDAMENTAL OF ETHANE

Author Institution: Theoretical Division, Los Alamos Scientific Laboratory; Department of Physics and Astronomy, University of TennesseeThe Q branches $^{P}Q_{6}$ through $^{R}Q_{9}$ of the $\nu_{9}$ ethane fundamental at 821 $cm^{-l}$ have been resolved at $300^\circ K$ using tunable diode lasers. A preliminary analysis yields $\Delta B = (- 1.27 \pm 0.02) \times 10^{-3} cm^{-1}$. Several of the branches exhibit line splittings that may result from the tunneling of the hindered rotation of the ethane molecule