Fig. 1: Overview of the experiment.
From: Conformer-specific polar cycloaddition of dibromobutadiene with trapped propene ions
a Scheme of the polar cycloaddition reaction between the gauche and s-trans conformers of 2,3-dibromobutadiene (DBB) with propene ions exhibiting reaction rate constants kg and kt, respectively. The red and blue colours indicate the dienophile and the diene moieties, respectively. b Schematic of the experimental setup. The two conformers of DBB were separated by electrostatic deflection of a molecular beam and directed at an ion trap containing sympathetically cooled propene ions. Reaction products were measured by ion extraction into a time-of-flight mass spectrometer (TOF-MS). c–e Fluorescence images showing slices through laser-cooled Ca+ Coulomb crystals at different stages of the experiment: c shows the initial, pure Ca+ crystal, d shows an image after loading propene ions by vacuum-ultraviolet (VUV) photoionisation of propene and e is a typical image obtained after the reaction with DBB. Arrows indicate regions where ions heavier than Ca+ accumulate in the trap.
