Lanthanide clusters with internal Ln ions: highly emissive molecules with solid-state cores.

Area of Science:

• Inorganic Chemistry
• Materials Science
• Nanotechnology

Background:

• Lanthanide clusters offer unique properties for materials science.
• Developing novel molecular clusters with encapsulated metal ions is a key research area.
• Erbium complexes are of interest for optical applications, particularly at 1544 nm.

Purpose of the Study:

• To synthesize and characterize novel erbium-chalcogenide clusters.
• To investigate the structural diversity and properties of these new clusters.
• To explore the potential of these molecular clusters as luminescent materials.

Main Methods:

• Reaction of erbium precursors with elemental sulfur and selenium.
• X-ray crystallography for structural determination of the synthesized clusters.
• Photoluminescence spectroscopy to analyze fluorescence properties.

Main Results:

• Synthesis of a double cubane cluster (THF)10Er6S6I6.
• Formation of a novel Er10 cluster (THF)14Er10S6Se12I6 with internal, chalcogen-encapsulated erbium ions.
• The Er10 cluster exhibits strong fluorescence at 1544 nm (decay time 3 ms, quantum efficiency 78%).
• Unprecedented fluorescence properties attributed to a low phonon energy environment.

Conclusions:

• The synthesized Er10 cluster represents the first lanthanide cluster with internally encapsulated lanthanide atoms.
• The observed fluorescence is comparable to Er-doped solid-state materials.
• The unique structure provides a low phonon energy host, enabling unusual spectral properties for molecular erbium complexes.