Luminescence in phosphine-stabilized copper chalcogenide cluster molecules--a comparative study.

Area of Science:

• Inorganic Chemistry
• Materials Science
• Computational Chemistry

Background:

• Copper chalcogenide clusters are of interest for their unique electronic and optical properties.
• Understanding the relationship between cluster structure and photophysical behavior is crucial for designing new materials.

Purpose of the Study:

• To investigate the electronic properties of eight copper chalcogenide clusters.
• To correlate spectroscopic and computational data with structural variations.
• To assess the photoluminescence (PL) characteristics and photostability of these compounds.

Main Methods:

• Experimental investigation using absorption and photoluminescence (PL) spectroscopy.
• Theoretical calculations employing time-dependent density functional theory (TD-DFT).
• Analysis of electronic transitions and visualization of difference densities.

Main Results:

• TD-DFT calculations successfully reproduced experimental electronic absorption spectra.
• Higher energy transitions involve electron excitation from cluster core to ligand orbitals.
• Lower energy transitions are highly dependent on the ligand surface structure.
• Bright red PL was observed for 'Cu12S6' and 'Cu24S12' cores, with quenching in specific ferrocenyl-containing complexes.
• Isomeric 'Cu20S10' clusters exhibited distinct emissions (820 nm for prolate, 575 nm for oblate).
• All complexes showed microsecond-scale emission decay at room temperature.
• Exceptional photostability was noted for [Cu12S6(dpppt)4] under anaerobic conditions.

Conclusions:

• Ligand choice significantly impacts the electronic and photoluminescence properties of copper chalcogenide clusters.
• The study provides insights into structure-property relationships for designing functional nanomaterials.
• These copper chalcogenide clusters demonstrate promising luminescent behavior and photostability.