Crystal structure of [μ-1κ

Area of Science:

• Organometallic Chemistry
• Coordination Chemistry
• Crystallography

Background:

• Osmium complexes are of interest due to their unique electronic properties and catalytic potential.
• Understanding the bonding and structural characteristics of di-osmium complexes is crucial for designing new materials.

Purpose of the Study:

• To characterize the molecular structure of the osmium complex (μ-η4-C4Ph4)Os2(CO)6.
• To investigate the nature of the osmium-osmium bond and the coordination environment around each osmium atom.

Main Methods:

• Single-crystal X-ray diffraction was employed to determine the three-dimensional structure of the complex.
• Analysis of bond distances, angles, and ligand conformations provided insights into the bonding.
• Disorder in specific ligands was modeled and refined.

Main Results:

• The complex features a metallacyclopenta-diene ring with one osmium atom integrated into the ring and the second osmium atom π-bonded.
• An osmium-osmium single bond of 2.7494(2) Å was identified, consistent with typical Os-Os single bond lengths.
• Each osmium atom is coordinated to three carbonyl ligands, adopting an eclipsed conformation with no bridging carbonyls. Significant disorder was observed in two carbonyl ligands and four phenyl groups.

Conclusions:

• The structural analysis confirms the formation of a di-osmium complex with a defined Os-Os single bond and specific ligand arrangement.
• The observed disorder provides information about the conformational flexibility of the phenyl and carbonyl ligands in the solid state.