We report the first coherent Raman detection of small van der Waals aggregates formed in dilute CO2/He free-jet expansions. CARS spectra show distinct features attributable to dimers and higher-order polymers of CO2. Comparison of these Raman data with infrared spectra in the ν1 region of CO2 indicates that the rule of mutual exclusion is operative for the dimer vibrations. This result favors an offset parallel C2h structure for the most stable dimer configuration rather than a polar T-shaped arrangement proposed from recent electric deflection experiments.
All Science Journal Classification (ASJC) codes
- Physics and Astronomy(all)
- Physical and Theoretical Chemistry