Fluorescence resonance energy transfer in atomically precise metal nanoclusters by cocrystallization-induced spatial...

Area of Science:

• Nanomaterials Science
• Quantum Chemistry
• Spectroscopy

Background:

• Fluorescence resonance energy transfer (FRET) studies at the atomic level are limited by the lack of systems with defined molecular distances and orientations.
• Metal nanoparticles, particularly copper nanoclusters, offer unique optical properties but controlling their interactions remains challenging.

Purpose of the Study:

• To demonstrate and understand atomic-level FRET between two distinct, atomically precise copper nanoclusters.
• To establish a system for precise spatial confinement of nanoclusters to facilitate FRET studies.
• To elucidate the influence of distance and dipole orientation on FRET processes at the electronic level.

Main Methods:

• Cocrystallization of two types of atomically precise copper nanoclusters: Cu ₈(p-MBT) ₈(PPh ₃) ₄ and Cu ₁₀(p-MBT) ₁₀(PPh ₃) ₄.
• Exploiting spectral overlap between the excitation of one cluster and the emission of the other.
• Utilizing density functional theory (DFT) calculations to analyze electronic structures, distances, and dipole orientations.

Main Results:

• Successful establishment of FRET between Cu ₈(p-MBT) ₈(PPh ₃) ₄ and Cu ₁₀(p-MBT) ₁₀(PPh ₃) ₄ nanoclusters within a cocrystallized system.
• Demonstration that cocrystallization-induced spatial confinement enables controlled FRET.
• DFT calculations provided insights into the electronic mechanisms governing FRET based on inter-cluster distance and dipole alignment.

Conclusions:

• Cocrystallization is an effective strategy for achieving atomic-level FRET in metal nanoclusters by controlling spatial confinement.
• The study provides a robust platform for investigating FRET mechanisms at the atomic scale.
• This work paves the way for designing novel nanomaterials with tailored optical properties through controlled energy transfer.