A novel crossed-molecular-beam experiment for investigating reactions of state- and conformationally selected strong-field-seeking molecules

Abstract

The structure and quantum state of the reactants have a profound impact on the kinetics and dynamics of chemical reactions. Over the past years, significant advances have been made in the control and manipulation of molecules with external electric and magnetic fields in molecular-beam experiments for investigations of their state-, structure-and energy-specific chemical reactivity. Whereas studies for neutrals have so far mainly focused on weak-field-seeking species, we report here progress towards investigating reactions of strong-field-seeking molecules by introducing a novel crossed-molecular-beam experiment featuring an electrostatic deflector. The new setup enables the characterisation of state-and geometry-specific effects in reactions under single-collision conditions. As a proof of principle, we present results on the chemi-ionisation reaction of metastable neon atoms with rotationally state-selected carbonyl sulfide (OCS) molecules and show that the branching ratio between the Penning and dissociative ionisation pathways strongly depends on the initial rotational state of OCS.

Basic features of Ne*–HX (X = Cl, Br) chemi-ionization reactions

“…Finally, present results, combined with those recently obtained in experiments performed under state resolved conditions on other systems, 20 provide additional-basic details on the stereodynamics of CHEMI involving molecules.…”

Multipole-moment effects in ion–molecule reactions at low temperatures: part I – ion-dipole enhancement of the rate coefficients of the He+ + NH3 and He+ + ND3 reactions at collisional energies Ecoll/kB near 0 K

“…The generation of pure samples of molecules in high-field-seeking states of the category A seems particularly attractive in this regard, and recent experiments have demonstrated ways of generating such samples. 81 Calculations of the (nonadiabatic) dynamics on the multidimensional potential-energy surfaces involved would be needed to interpret the observed branching ratios and the fact that only ∼40% of the close collisions appear to be reactive.…”

The topology of the reaction stereo-dynamics in chemi-ionizations and ion chemistry

“…CHEMI are of great interest for fundamental and applied research 7,8,[13][14][15][16][17][18][19][20][21][22][23][24][25][26][27][28][29][30][31][32] since they participate to the balance of elementary processes in several environments, where X * easily forms. They happen both at very low temperature T (under conditions of the cold chemistry), as in interstellar medium, at intermediate T values, as in planetary atmospheres, and at high T, as in flames and plasmas.…”