The rhenium tris(dithiolene) electron transfer series: calibrating covalency

Area of Science:

• Inorganic Chemistry
• Coordination Chemistry
• Spectroscopy

Background:

• Rhenium tris(dithiolene) complexes represent a versatile class of compounds with tunable electronic properties.
• Understanding the electron transfer series and associated structural changes is crucial for designing new functional materials.

Purpose of the Study:

• To synthesize and characterize four members of the rhenium tris(dithiolene) electron transfer series.
• To elucidate the electronic structures and bonding characteristics of these complexes.
• To investigate the covalency in frontier orbitals using spectroscopic and computational methods.

Main Methods:

• Synthesis and structural characterization of rhenium tris(dithiolene) complexes.
• Sulfur K-edge X-ray absorption spectroscopy (XAS) for electronic structure determination.
• Computational methods including time-dependent density functional theory (TD-DFT) for electronic structure analysis.

Main Results:

• Structural characterization of monoanionic and dianionic rhenium tris(dithiolene) complexes revealed distorted trigonal prismatic and octahedral geometries, respectively.
• XAS and computational analyses unambiguously defined the electronic structures of the four complexes, including metal oxidation states and ligand reduction.
• Two distinct methods were employed to estimate sulfur 3p character in frontier orbitals, providing insights into covalency.

Conclusions:

• The study provides a comprehensive understanding of the electron transfer series of rhenium tris(dithiolenes).
• The results refine the description of electronic structures in related molybdenum and tungsten complexes.
• This work contributes to the fundamental understanding of bonding and electronic properties in transition metal dithiolene complexes.