Ion-molecule reactions catalyzed by a single gold atom

Area of Science:

• Physical Chemistry
• Catalysis
• Atomic Physics

Background:

• Van der Waals complexes are crucial for studying fundamental chemical reactions.
• Superfluid helium nanodroplets provide a unique environment for complex formation and reaction studies.
• Gold atoms are known for their catalytic properties in various chemical processes.

Purpose of the Study:

• To investigate the catalytic role of gold (Au) atoms in van der Waals complexes.
• To explore the ionization-induced chemistry of 1,6-hexanediol-Au and 1,8-octanediol-Au complexes.
• To understand the mechanism of gold-atom-mediated bond cleavage in these complexes.

Main Methods:

• Formation of 1,6-hexanediol-Au and 1,8-octanediol-Au complexes in superfluid helium nanodroplets.
• Induction of chemical reactions via ionization.
• Analysis of reaction products, particularly C2H4+.
• Density Functional Theory (DFT) calculations to model reaction pathways and bond strengths.

Main Results:

• Gold atoms were observed to act as catalysts in the studied van der Waals complexes for the first time.
• The addition of gold atoms led to C2H4+ being the sole prominent product in dissociative reactions.
• DFT calculations revealed that gold atoms strengthen C-C bonds while weakening C-O bonds in the ionized complexes.
• Preferential cleavage of C-O bonds was observed, indicating a strong catalytic effect.

Conclusions:

• Gold atoms can function as effective catalysts within van der Waals complexes.
• The catalytic activity of gold stems from its ability to selectively weaken specific bonds (C-O) while strengthening others (C-C) in ionized molecules.
• This study opens new avenues for utilizing atomic gold in catalytic applications within novel complex systems.