Quantum-state-controlled channel branching in cold Ne(3P2)+Ar chemi-ionization

General treatment for stereo-dynamics of state-to-state chemi-ionization reactions

“…Experimental observables and interaction potential formulation. The proposed treatment has been stimulated by experimental findings from collision energy dependence measurements of total and partial ionization cross sections (σ) 8,30 , associative to Penning (σ as /σ pe ) ratios [31][32][33][34] and Penning Ionization Electron Spectra (PIES) 25,30,35 the latter representing a sort of TS spectroscopy.…”

“…Experimental technique. All experimental data, investigated in this paper, have been measured in gas phase with the molecular beam (MB) technique applied under single collision and high resolution conditions 8,[30][31][32][33][34] . A schematic view of MB apparatus available in our laboratory and extensively described elsewhere 27,28,35 , is given in the Supplementary Methods and Supplementary Fig.…”

“…Moreover, the imaginary part formulation is fully discussed in the previous section (see, in particular, Eqs. [22][23][24][25][26][27][28][29][30][31][32][33]. Points represent peak area ratios with their relative error bars extracted from the analysis of Ne * -Kr PIESs measured as a function of the collision energy, where the contributions of four reaction channels, associated to two different spin-orbit states J of Ne * neutral reactant (J i = 2, 0) and of Kr + ( 2 P J ) ionic product (J f = 3/2, 1/2), have been resolved (see text and Supplementary Fig.…”

Probing the location of the unpaired electron in spin–orbit changing collisions of NO with Ar

“…18 Observations of resonances in other high-resolution experiments of molecular interactions, including in vibrational excitation studies, 8,11 have demonstrated similar sensitivities to the corresponding calculated energy levels and PESs. [5][6][7]9,14,29 In addition to probing the local energy landscape via dynamical resonances, initial alignment 23,[30][31][32][33][34][35][36][37][38] or orientation [39][40][41][42][43][44] of selected reactant quantum states can be used to gauge the geometric preferences and uncover the associated reaction pathways of molecular encounters. 37,38 In this case, specific portions of the PES can be explored selectively by confining the relative geometry of the interacting species.…”

“…Spatial alignment (alignment parallel or perpendicular to a reference axis) through polarized laser light has revealed pronounced preferences for specific initial configurations, 30,[33][34][35][36][37][38] and even enabled the three-dimensional visualization of distinct microscopic reaction pathways. 23 Molecular orientation, in which a specific end or side of a molecule can be directed towards a collision partner, is most widely achieved through hexapole state selection coupled with adiabatic passage into a static electric [40][41][42]45,46 or magnetic 43,44,47 field. The good agreement between experimental and calculated steric preferences obtained in studies of inelastic collisions of state selected NO(X) with Ar and He atoms [40][41][42][48][49][50][51] have confirmed the accuracy of the NO(X) + He/Ar ground electronic PESs, [52][53][54] while (unoriented) scattering experiments of electronically excited NO(A) with Ne 17 pointed to shortcomings in the calculated PESs.…”