Five- and Six-Coordinate Group 4 Compounds Stabilized by beta-Ketiminate and Diketiminate Ligands: Syntheses and...

Area of Science:

• Organometallic Chemistry
• Coordination Chemistry
• Materials Science

Background:

• Beta-diketiminate ligands offer versatile coordination possibilities in organometallic chemistry.
• Titanium and zirconium complexes are crucial in catalysis and materials science.

Purpose of the Study:

• To describe the preparation and reaction chemistry of beta-diketiminate titanium and zirconium complexes.
• To investigate the control of coordination modes and structural properties of these metal complexes.
• To elucidate the mechanism of isomerization in zirconium complexes.

Main Methods:

• Amine and salt elimination reactions for ligand introduction.
• X-ray diffraction for structural determination.
• Dynamic NMR spectroscopy to probe isomerization mechanisms.

Main Results:

• Successful synthesis of beta-diketiminate titanium and zirconium complexes.
• Control over eta(5)- and eta(2)-coordination modes by ligand modification.
• Structural characterization of five- and six-coordinate complexes.
• Identification of Bailar-twist mechanism for isomerization in zirconium complexes.

Conclusions:

• Beta-diketiminate ligands can be effectively introduced to titanium and zirconium metal centers using various synthetic strategies.
• Ligand modification allows control over coordination modes and complex geometries.
• Dynamic NMR studies provide mechanistic insights into the isomerization of metal complexes.