Electric deflection of imidazole dimers and trimers in helium nanodroplets: Dipole moments, structure, and fragmentation

Abstract

Deuterated imidazole (IM) molecules, dimers and trimers formed in liquid helium nanodroplets are studied by the electrostatic beam deflection method. Monitoring the deflection profile of (IM)D + provides a direct way to establish that it is the primary product of the ionization-induced fragmentation both of (IM)2 and (IM)3. The magnitude of the deflection determines the electric dipole moments of the parent clusters: nearly 9 D for the dimer and 14.5 D for the trimer. These very large dipole values confirm theoretical predictions and derive from a polar chain bonding arrangement of the heterocyclic imidazole molecules.

Probing the presence and absence of metal-fullerene electron transfer reactions in helium nanodroplets by deflection measurements

“…For the conditions employed in the present measurements, the mean size was found to be ≈2×10 4 helium atoms per droplet. Using this information and the "field-off" profile as input, we perform a Monte Carlo simulation of the deflection, as detailed in our previous publications, 12,23,27,28 accounting for droplet shrinkage by evaporation and for the pick-up and ionization probabilities, and solve for the dipole moment of the embedded complex by fitting the simulated "field-on" profile to the data.…”

Pickup and reactions of molecules on clusters relevant for atmospheric and interstellar processes

“…121 Some special methods were developed, such as elastic scattering [122][123][124] and sodium doping with subsequent photodetachment of electrons, 101,102 the latter of which was later proposed as the sizer for neutral weakly bound ultrafine aerosol particles. 103,104 Clusters can be also deflected according to their sizes in strong inhomogeneous electric fields due to their size-dependent dipole moments and polarizability, [125][126][127] which is, however, limited to small complexes. None of the above methods is universal.…”

Out-of-focus spatial map imaging of magnetically deflected sodium ammonia clusters

“…Non-movable slit experiments quantify deflection by comparing the measured ion intensities that pass the slit with and without magnetic field. 8,9 Scanning experiments involve displacing the slit [10][11][12] or the ionization laser [13][14][15] along the deflection axis and recording the mass signals at each displacement position. This provides more information on the spatial deflection pattern, but it is more time-consuming and may lead to intensity variations due to experimental instabilities.…”