Knowledge Bank

The $\nu 1$ and $\nu 3$ bands of chloronium ion($H2C\ell +$) have been observed with a difference frequency laser system at NRC. The ion was generated through a hollow cathode discharge modulated at 16 kHz in a gas mixture of $HC\ell (\sim 30mTorr)$ and $H2(\sim 0.7Torr)$. The observation was done with a dry-ice cooled multiple traversal cell connected to a fast flow pumping system. The assignment was not easily made due to the Coriolis interaction between the $\nu 1=1$ and $\nu 3=1$ states. The first clue of the assingment was obtained by a systematic sorting for the ground state combination differences which were known from the analysis of the $\nu 2$ band by Kawaguchi and $Hirota.1$ A least squares fit of the observed transitions has been done by employing Watson's A-reduced Hamiltonian, and the band origins, rotational constants, and centrifugal distortion constants have been obtained.