Knowledge Bank

Bending vibrations have been observed in the $A2\pi u-X2\Pi g$ transition of $CO2+$ when the excited ions are produced by collisions of $CO2$ with a beam of $He+$ ions. Bending vibrations in the A state of $CO2+$ have not been observed previously. Electron Impact and photon absorption do not excite the bending modes, Excitation by $He+$ impact has been observed up to at least v2 = 10 in the A state. Similar excitation has been observed for $CO2$ collisions with $Ar+$ and $Kr+$ but not with $H+$. Several emission features in the $B2\Sigma u+-X2\pi g$ region excited by heavy ion impact are tentatively ascribed to bonding vibrations but have not been definitely identified, Spectroscopic measurements have been carried out at medium resolution on $\mathrm{<mrow\; data-mjx-texclass="ORD">12</mrow>}CO2$ and $\mathrm{<mrow\; data-mjx-texclass="ORD">13</mrow>}CO2$. Vibrational constants will be presented.