Complexes of gold and imidazole formed in helium nanodroplets

TL;DR

This study investigates gold-imidazole complexes formed in helium nanodroplets, revealing specific stable cluster sizes and their formation mechanisms through experimental detection and theoretical calculations.

Contribution

It provides new insights into the stability and fragmentation patterns of gold-imidazole complexes in helium nanodroplets, combining experimental and computational approaches.

Findings

Identification of 'magic' cluster sizes with enhanced abundance.

Stable complexes like AuIm₂⁺ are particularly favored.

Transition from imidazole loss to gold atom loss in fragmentation patterns.

Abstract

We have studied complexes of gold atoms and imidazole (C$_3$N$_2$H$_4$, abbreviated Im) produced in helium nanodroplets. Following the ionization of the doped droplets we detect a broad range of different Au$_m$Im$_n^+$ complexes, however we find that for specific values of $m$ certain $n$ are "magic" and thus particularly abundant. Our density functional theory calculations indicate that these abundant clusters sizes are partially the result of particularly stable complexes, e.g. AuIm$_2^+$, and partially due to a transition in fragmentation patterns from the loss of neutral imidazole molecules for large systems to the loss of neutral gold atoms for smaller systems.