Knowledge Bank

When a Ne:$CO2$ sample is codeposited with a beam of neon atoms excited in a microwave discharge, both $CO2+$ and $CO2-$ are stabilized in sufficient concentration for the detection of their antisymmetric stretching absorption, $\nu 3$. The position of the absorption for $CO2+$ is in excellent agreement with that recently reported for the gas-phase ion. The positions of the corresponding abaorptions of the carbon-13 and oxygen-18 substituted species, reported for the first time, support the assignment. The $\nu 3$ absorption of $CO2-$ is significantly shifted from the position previously reported for this fundamental of the $M+CO2-$ species $(M=Li,Na,K,Cs)$ isolated in an argon matrix. Photodetachment of $CO2-$ occurs when the sample is exposed to radiation in the visible spectral region. Evidence will be presented for the stabilization of the $CO2\cdots CO2-$ cluster ion in the present experiments.