This presentation describes an aggressive program broadly aimed at the elucidation of complex ion-molecule chemistry across a wide temperature range. Using variable-temperature ion-trapping and molecular-beam techniques to study chemistry of ions under isolated collision conditions, with control over ion generation, collisional cooling, and molecular delivery.  The program provides new knowledge relevant to chemical processes in extreme environments at and away from equilibrium. These conditions emulate the environment surrounding comets and stars, planetary ionospheres and deep within interstellar media. The results also allow for precise determination of reactivity and dynamics under unique conditions allowing new insights into detailed reaction mechanisms and addressing the nature of reactive encounters of strongly coupled systems.The field of low-temperature ion-molecule kinetics has seen many innovations in the past generation. These developments opened the ability for direct measurement of reaction rates in the temperature window below 200 K. Supersonic flows allowed routine study of ion-molecule collisions at T< 200 K.However, owing to the constraints of shock-free supersonic flow, it is difficult to initiate new chemistry, chemically probe the flow, or quench reactions, once the flow is established.Ion traps avoid many of these problems. We have demonstrated the ability to chemically synthesize HOC+ from trapped/cooled CO+ followed by temporal product quenching using a chemical probe (CH4 or NO) for residual HOC+.1 We have taken the ion-trap technique to the next level and constructed an effusive molecular-beam source for delivery of thermalized cold molecules. This approach allows studies of low-temperature ion-molecule reactions of complex neutral systems. This new instrument forms the foundation of the science presented here.2,31)Smith, M. A., Schlemmer, S., von Richthofen, J. and Gerlich, D., Astophys. J. 578, L87-L90 (2002).2) Smith, M.A., Yuan, B.; Sanov, A. and Smith, M. A., J. Phys. Chem. A, 116, 9466-9472 (2012).3) Smith, M.A., Yuan, B., Scott, Z. and Sanov, A., J. Phys. Chem. A, 116, 11596-11600 (2012).

Ion traps for the laboratory study of extreme environments: Kinetics at low temperatures and pressures

247th National Meeting (2014)

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