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Structural and electronic properties of old and new A2[M(pin(F))2] complexes
Laleh Tahsini1, Sarah E Specht, June S Lum
1Chemistry Department, Boston University , 590 Commonwealth Avenue, Boston, Massachusetts 02215, United States.
Inorganic Chemistry
|November 23, 2013
Summary
New homoleptic metal complexes featuring the dodecafluoropinacolate ligand were synthesized and characterized. Perfluorination enables unusual metal centers and access to rare oxidation states like Ni(III) and Cu(III).
Area of Science:
- Coordination Chemistry
- Organometallic Chemistry
- Materials Science
Background:
- The dodecafluoropinacolate (pin(F))(2-) ligand is a perfluorinated analogue of pinacolate.
- Understanding the impact of ligand perfluorination on metal complex geometry and redox properties is crucial.
- Exploration of unusual oxidation states in transition metal complexes remains an active research area.
Purpose of the Study:
- To synthesize and characterize new homoleptic metal complexes with the dodecafluoropinacolate ligand.
- To investigate the structural, electronic, and redox properties of these novel complexes.
- To determine the influence of ligand perfluorination on metal center coordination and accessibility of high oxidation states.
Main Methods:
- Synthesis of seven new homoleptic complexes: A2[M(pin(F))2].
- Characterization using UV-vis spectroscopy, cyclic voltammetry, elemental analysis, and magnetic susceptibility (Evans method).
- Single-crystal X-ray crystallography for structural determination (except for complex 5).
Main Results:
- Square-planar geometries observed for Fe, Ni, and Cu complexes; distorted square-planar for Co; tetrahedral for Zn.
- Perfluorination increases the central C-C bond length due to steric effects of CF3 groups.
- Reversible Ni(III)/Ni(II) and Cu(III)/Cu(II) redox couples were observed, indicating access to rare oxidation states.
Conclusions:
- The dodecafluoropinacolate ligand facilitates the formation of coordinatively unsaturated, high-spin metal centers.
- Perfluorination of the pinacolate ligand provides thermodynamic access to rare oxidation states (Ni(III), Cu(III)).
- These findings open avenues for designing novel metal complexes with unique electronic and catalytic properties.
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