THE OBSERVATION OF THE $\nu_{1}$ (NH STRETCH) AND $\nu_{2}$ (CH STRETCH) OF $HCNH^{+}$

Author Institution: Department of Chemistry and Department of Astronomy, and Astrophysics, University of ChicagoHigh resolution vibration-rotation spectra have been observed for both the $\nu_{1}$ (NH) and $\nu_{2}$ (CH) stretching modes of the astrophysically important molecular ion, $HCNH^{+}$, using a difference frequency laser spectrometer. This first spectroscopic measurement of $HCNH^{+}$ shows that the structure is linear with the following spectroscopic constants. $\begin{array}{lll}&\nu_{1} (NH Stretch)& \nu_{2} (CH Stretch)\\ \nu_{0} (cm^{-1})& 3482.84409(105)& 3187.86375(41) \\B_{1} (cm^{-1}) &1.228633(38)& 1.228494(19) \\B_{0} (cm^{-1})& 1.236024(37)& 1.236067(18)\\ D_{1} (cm^{-1}) &1.574(43) \times 10^{-6}& 1.610(22) \times 10^{-6}\\ D_{0} (cm^{-1})& 1.596(42) \times 10^{-6}& 1.620(21) \times 10^{-6}\\ \end{array}$The experimental results will also be discussed in light of several excellent theoretical calculations which have been made