Protonated and Cationic Helium Clusters.

Linnea Lundberg,Paul Scheier,Peter Bartl,Michael Gatchell,Christian Leidlmair

doi:10.3390/molecules25051066

Linnea Lundberg, Paul Scheier + Show 3 more

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https://doi.org/10.3390/molecules25051066

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Abstract

Protonated rare gas clusters have previously been shown to display markably different structures compared to their pure, cationic counterparts. Here, we have performed high-resolution mass spectrometry measurements of protonated and pristine clusters of He containing up to 50 atoms. We identify notable differences between the magic numbers present in the two types of clusters, but in contrast to heavier rare gas clusters, neither the protonated nor pure clusters exhibit signs of icosahedral symmetries. These findings are discussed in light of results from heavier rare gases and previous theoretical work on protonated helium.

Highlights

One of the first things a chemistry student learns when encountering the periodic table is that elements in the last column, group 18, or the noble gases, are unreactive and do not form chemical bonds
That in most cases are only ever found in molecular compounds, be they homonuclear or heteronuclear, we learn that the noble gas elements exist as solitary atoms
This is, as it turns out, only part of the truth. Electronegative ligands, such as O and F atoms, have been found to be able to form neutral, covalently bound structures with Ar, Kr, and Xe, with the latter in particular displaying a rich chemical nature, but neutral compounds containing bound He and Ne have generally not been achieved [1,2,3]. Exotic exceptions to this are compounds formed under extreme pressures [4] or by trapping noble gases in molecular cages [3,5,6]

Summary

Introduction

One of the first things a chemistry student learns when encountering the periodic table is that elements in the last column, group 18, or the noble gases, are unreactive and do not form chemical bonds. 1980s, a large body of work began to emerge as cationic clusters of rare gas atoms were produced by the expansion of cooled gases and studied by means of mass spectrometry.

Results

Conclusion