Isotopic exchange of O(1D) with carbon dioxide

Abstract

The photolysis of carbon dioxide with xenon resonance radiation (1470 Å) has been used as a source of excited atomic oxygen O(¹D). The exchange and quenching reactions of O(¹D) with carbon dioxide have been investigated by measuring the rate of growth of CO¹⁶O¹⁸ in a photolyzed mixture of CO¹⁶O¹⁶ and CO¹⁸O¹⁸. The probability αN of incorporation of each O(¹D) into a CO₂ molecule before quenching can occur is 0.69. Possible interpretations of this result are discussed. The simplest explanation of the exchange kinetics is provided by the intermediate formation of CO₃. This species must be sufficiently long lived for internal energy equilibration to take place.