A density functional study on cationic Au(n)Cu(m)+ clusters and their monocarbonyls.

Area of Science:

• Computational chemistry
• Materials science
• Surface science

Background:

• Gold clusters often form planar structures.
• Understanding bimetallic cluster properties is crucial for catalysis.
• Carbonyl complexes are important in chemical reactions.

Purpose of the Study:

• Investigate the structural and electronic properties of cationic gold-copper clusters (Au(n)Cu(m)+).
• Analyze the interaction of carbon monoxide (CO) with these bimetallic clusters.
• Determine the factors influencing CO binding and potential reactivity.

Main Methods:

• First-principles calculations were employed.
• Density Functional Theory (DFT) was used to model cluster structures and energies.
• Frontier molecular orbital theory explained CO binding preferences.

Main Results:

• Copper substitution weakens the planar structure trend in gold clusters.
• An odd-even oscillation in electron affinity was observed with varying atom numbers.
• CO preferentially binds to copper atoms, with binding energy decreasing as copper content increases.
• Electron transfer between CO and the cluster influences binding energy.
• Reactive collisions between CO and Au3Cu+ may cause gold atom loss.

Conclusions:

• The electronic and structural properties of Au(n)Cu(m)+ clusters are sensitive to composition.
• CO binding is primarily governed by interactions with copper atoms and electron transfer dynamics.
• The Au3Cu+ cluster shows potential for dissociation upon reaction with CO, indicating specific reactivity pathways.