Alkynyl-Stabilized Superatomic Silver Clusters Showing Circularly Polarized Luminescence

Area of Science:

• Materials Science
• Nanotechnology
• Chirality Studies

Background:

• Superatomic metal clusters are gaining attention for their unique electronic and optical properties.
• Chirality in materials can lead to specialized optical phenomena like circularly polarized luminescence (CPL).
• Developing methods to control and induce chirality in nanomaterials is crucial for advanced applications.

Purpose of the Study:

• To synthesize and characterize a new enantiomeric pair of superatomic silver clusters.
• To investigate the near-infrared (NIR) light emission and CPL properties of these chiral silver clusters.
• To elucidate the origin of CPL in these systems and understand chirality transfer mechanisms.

Main Methods:

• Synthesis of R/S-Ag clusters using chiral alkynyl ligands.
• Spectroscopic analysis to determine optical properties, including quantum yield (QY).
• Experimental and theoretical calculations to probe electronic structure and CPL origin.

Main Results:

• Successful preparation of enantiomeric superatomic silver clusters (R-Ag and S-Ag) with C3 symmetry.
• Observation of NIR light emission with an 8.0% quantum yield under ambient conditions.
• Detection of NIR circularly polarized luminescence (CPL) attributed to chiral excited states.
• Identification of CPL origin from electronic transitions between superatomic 1P and 1S orbitals.

Conclusions:

• Chiral alkynyl ligands can effectively induce chirality in superatomic silver clusters.
• The study provides the first experimental and theoretical evidence for CPL originating from superatomic orbital transitions.
• This work establishes a new strategy for designing CPL-active metal nanoclusters and understanding chirality transfer in nanomaterials.