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

TL;DR

This study measures the electric dipole moments of imidazole dimers and trimers in helium nanodroplets, revealing their structure and fragmentation behavior through beam deflection experiments.

Contribution

It provides direct experimental measurements of dipole moments for imidazole clusters, confirming theoretical predictions about their polar chain structures.

Findings

Dipole moment of dimer is nearly 9 D.

Dipole moment of trimer is 14.5 D.

Fragmentation primarily produces deuterated imidazole ions.

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.