Cu₄I₄-cubane clusters based on 10-(aryl)phenoxarsines and their luminescence

Area of Science:

• Inorganic Chemistry
• Materials Science
• Photophysics

Background:

• Tetranuclear copper(i) cubane-type clusters are of interest due to their unique structural and photophysical properties.
• Phenoxarsine ligands offer tunable electronic and steric properties for modifying metal cluster behavior.

Purpose of the Study:

• To synthesize and characterize novel tetranuclear copper(i) cubane-type Cu4I4 clusters incorporating various 10-(aryl)phenoxarsine ligands.
• To investigate the structural, photophysical, and theoretical properties of these synthesized complexes.
• To understand the origin of their luminescence properties through computational analysis.

Main Methods:

• Synthesis of five distinct 10-(aryl)phenoxarsine ligands and subsequent formation of Cu4I4 clusters.
• Structural characterization using NMR spectroscopy, mass spectrometry, elemental analysis, and single-crystal X-ray diffraction.
• Photophysical characterization including UV/Vis absorption and emission spectroscopy.
• Theoretical studies employing Density Functional Theory (DFT) and time-dependent DFT (TD-DFT) calculations.

Main Results:

• Successful synthesis and structural confirmation of five new Cu4I4 clusters with diverse phenoxarsine ligands.
• Detailed structural analysis revealed the cubane-type core structure.
• UV/Vis absorption and emission studies showed intense green luminescence in the solid state under UV irradiation.
• DFT calculations provided insights into the electronic structure and rationalized the observed photophysical properties.

Conclusions:

• The synthesized tetranuclear copper(i) cubane-type Cu4I4 clusters with 10-(aryl)phenoxarsine ligands are structurally characterized and photophysically investigated.
• The intense green emission observed in the solid state is attributed to a cluster-centered triplet state.
• Theoretical calculations successfully correlate the structural and electronic properties with the observed luminescence, offering a deeper understanding of these materials.