Knowledge Bank

A magnetically confined glow discharge has been used to produce protonated and deuterated nitrous oxide in a mixture of $N2O,H2/O2$ and Ar. A total number of 63 rotational lines for $HON2+$ and 89 for $DON2+$ characterized respectively by $5\le J\le 18,Ka\le 4$ and $0\le J\le 27,Ka\le 7$ have been observed in the 130 - 405 GHz frequency range. These lines belong to a-type $rp$ - branches and to b-type $rR\_Rq-$ and $rp$ - branches. From the analysis of these two types of spectrum, accurate molecular parameters have been derived which are in good agreement with recent IR experiments on $HON2+$ (1). The values obtained for the A rotational constant: $Ao=625957.716(52)MHzforHON2+andAo=349107.385(14)MHzforDON2+$ confirm the recent results of ab initio calculations leading to the conclusion that the preferred site of protonation is at the oxygen atom.