A ternary Cu-Sn-S cluster complex--(NBu4)[Cu19S28(SnPh)12(PEt2Ph)3]

Area of Science:

• Inorganic Chemistry
• Materials Science
• Nanotechnology

Background:

• Exploration of novel metal sulfide clusters is crucial for developing advanced functional materials.
• Copper-tin sulfide clusters offer unique electronic and optical properties.
• Synthesis and characterization of complex cluster architectures remain a significant challenge.

Purpose of the Study:

• To synthesize and characterize novel ionic mixed copper-tin sulfide clusters.
• To investigate the structural features of these clusters.
• To explore the photoluminescent properties of the synthesized compounds.

Main Methods:

• Reaction of copper(I) chloride (CuCl), phenyltin trichloride (PhSnCl3), and diethylphenylphosphine (PEt2Ph) with bis(trimethylsilyl) sulfide (S(SiMe3)2) in tetrahydrofuran (THF).
• Addition of tetrabutylammonium chloride (NBu4Cl) to selectively synthesize the target cluster.
• Structural characterization using single crystal X-ray diffraction.
• Photoluminescence spectroscopy to analyze optical properties.

Main Results:

• Successful synthesis of the ionic, mixed copper-tin sulfide cluster [Li(thf)4][Cu19S28(SnPh)12(PEt2Ph)3] and selectively (NBu4)[Cu19S28(SnPh)12(PEt2Ph)3].
• X-ray crystallography revealed a copper sulfide core decorated with phenyltin groups and phosphine ligands.
• The cluster anion possesses an open 'Cu3S3' face, shielded by counterions.
• The tetrabutylammonium salt exhibits bright, temperature-dependent near-infrared photoluminescence (approx. 820-930 nm) below 100 K.

Conclusions:

• The study reports the unexpected synthesis of complex copper-tin sulfide clusters.
• The structural analysis provides insights into the coordination chemistry of these novel materials.
• The observed near-infrared photoluminescence highlights the potential of these clusters for optoelectronic applications.