Some H/D exchange reactions involved in the deuteration of interstellar molecules

Abstract

Deuterium is commonly observed in interstellar molecules which vary in complexity from HD to CH3OD. Quantitative estimates of deuteration rateshave been hampered by the lack of appropriate kinetic data andthermodynamic data. Experimental investigations have, therefore, beeninitiated of ion-molecule reactions in which isotope exchange occurs,including reactions involving H/D exchange. A major objective of suchstudies is to determine the temperature variation of reaction ratecoefficients. The present investigation is mainly concerned with studiesof the reaction D(+) + H2 yields reversibly H(+) + HD, which generatesthe interstellar HD, and with the reactions H3(+) + HD yields reversiblyH2D(+) + H2, and CH3(+) + HD yields reversibly CH2D(+) + H2, which areboth probably important first steps in the synthesis of deuteratedmolecules.