Reaction kinetics at very low temperatures: Laboratory studies and interstellar chemistry

Studies of gas-phase processes at temperatures down to 10 K have recently b lossomed, largely through application of the CRESU (cinetique de reaction e n ecoulement supersonique uniforme) technique. The results are of considera ble relevance to the synthesis of molecules in dense interstellar clouds, d emonstrating that the models developed to explain the observed molecular ab undances must be expanded to include reactions between electrically neutral species. In addition, the experimental results have stimulated theoretical efforts to describe the factors that control the rates of such low-tempera ture reactions. In this Account, the CRESU method is described and the rele vance of the results discussed.