1 3C and 18O isotope enrichment by vibrational energy exchange pumping of CO

Measurements of preferential vibration-to-vibration (V–V) pumping of high vibrational states of 13C 16O and 12C 18O in optically excited CO gas are reported. It is found that the v=22, 25, 27, 30, and 32 states of 13C 16O and the v=8, 10, and 12 states of 12C 18O are substantially overpopulated compared to the same states in 12C 16O in strongly V–V pumped CO. Such mixtures are observed to react, forming products enriched in 13C. The results are in reasonable agreement with an analytical kinetic model of V–V pumping in binary mixtures of diatomic gases.