Vacancy-Induced Atomic Diffusion in a Molecular Metal Cluster Complex.

Area of Science:

• Inorganic Chemistry
• Materials Science
• Physical Chemistry

Background:

• Atomic vacancies in bulk materials facilitate atom migration and dynamics.
• The behavior of vacancies and induced atomic dynamics in discrete molecular clusters remains largely unexplored.

Purpose of the Study:

• To investigate vacancy-induced atomic dynamics in a discrete molecular cluster.
• To synthesize and characterize a palladium cluster complex with an atomic vacancy.
• To observe and understand the diffusion of palladium atoms within the cluster.

Main Methods:

• Synthesis of a close-packed Pd12 cluster complex with a palladium-atom vacancy.
• Variable-temperature Nuclear Magnetic Resonance (NMR) spectroscopy.
• X-ray structure analysis.
• Theoretical calculations.

Main Results:

• Generation of a Pd12 cluster complex exhibiting a Pd-atom vacancy.
• Observation of rapid diffusion of palladium atoms within the cluster.
• Identification of the atomic vacancy at surface sites of the Pd12 core, migrating rapidly on the NMR timescale.
• Demonstration of low-energy barrier self-diffusion for all surface palladium atoms.

Conclusions:

• Atomic diffusion via the vacancy mechanism is possible within discrete molecular entities.
• The study provides the first evidence of vacancy-induced dynamics in a molecular cluster.
• This finding opens new avenues for understanding and controlling atomic motion in nanoscale systems.