A [[TiCl2(isodiCp)]2(mu-O)] dimer and a twinned cyclic [TiCl(isodiCp)(mu-O)]4 tetramer

Area of Science:

• Organometallic Chemistry
• Coordination Chemistry
• Materials Science

Background:

• Titanium-oxo clusters are important in catalysis and materials science.
• Synthesis of novel titanium complexes with unique ligand architectures is of significant interest.
• The isodicyclopentadienide (isodiCp) ligand offers a unique framework for organometallic chemistry.

Purpose of the Study:

• To synthesize and characterize novel mu-oxo titanium dimers and tetramers.
• To investigate the structural properties of these complexes, including isomerism and ligand conformation.
• To explore the reactivity of titanium tetrachloride (TiCl4) with functionalized isodiCp ligands.

Main Methods:

• Synthesis via electrophilic attack of TiCl4 on an exo-trimethylsilyl derivative of isodiCp in the presence of moisture.
• Structural characterization using X-ray crystallography.
• Analysis of bond angles, dihedral angles, and crystallographic symmetry.

Main Results:

• Successful synthesis of a mu-oxo dimer [Ti2Cl4(mu-O)(C10H11)2] and a mu-oxo cyclic tetramer [Ti4Cl4(mu-O)4(C10H11)4].
• Both compounds are endo isomers with Ti atoms bonded in an eta 5 manner to the isodiCp ligand's Cp ring.
• Observed ligand bending (dihedral angles 9.0-10.2 degrees) and a bent Ti-O-Ti angle (159.5 degrees) in the dimer.
• The tetramer crystallizes in tetragonal form, exhibits a crystallographic 4 axis, and features an eight-membered Ti-O ring.

Conclusions:

• The study presents the first synthesis and structural elucidation of these specific mu-oxo titanium dimer and tetramer complexes.
• The results highlight the influence of the isodiCp ligand on the structural characteristics of titanium-oxo clusters.
• These findings contribute to the understanding of titanium cluster chemistry and the formation of novel inorganic frameworks.