Dioxidomolybdenum(VI) complex featuring a 2,4-di-fluoro-substituted amine bis-(phenolate) ligand

Area of Science:

• Inorganic Chemistry
• Bioinorganic Chemistry
• Crystallography

Background:

• Synthetic complexes with a cis-dioxomolybdenum(VI) core serve as crucial models for the molybdenum co-factor (Moco).
• Fluorinated ligands can influence the electronic and structural properties of metal complexes.

Purpose of the Study:

• To report the crystal structure of a novel synthetic molybdenum-dioxo complex featuring a tetra-dentate amine bis-(phenolate) ligand with fluorine substituents.
• To provide a more accurate structural and bonding description compared to previous studies through enhanced crystallographic data collection.

Main Methods:

• Single crystal X-ray diffraction at 150 K.
• Structure refinement using a wider 2θ range.
• Comparison of crystallographic data with previously reported structures.

Main Results:

• The crystal structure of [Mo(C18H18F4N2O2)O2] was determined, revealing distortions from ideal octahedral geometry around the Mo center.
• Key bond angles (O=Mo=O, N-Mo-O) and the dihedral angle between phenolate rings were precisely defined.
• π-π stacking interactions between aromatic rings were observed.
• The refined structure exhibits lower R1 and ωR2 values compared to prior room-temperature data, indicating improved accuracy.

Conclusions:

• The obtained crystal structure provides a more realistic representation of the bonding within the Mo(VI)=O moiety.
• The fluorinated tetra-dentate ligand effectively stabilizes the cis-dioxomolybdenum(VI) core.
• This work refines our understanding of Moco model complexes and their structural nuances.