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Published on: March 20, 2017
Monomeric Fe(iii) half-sandwich complexes [Cp'FeX2] - synthesis, properties and electronic structure
Matthias Reiners1, Miyuki Maekawa1, Dirk Baabe1
1Technische Universität Braunschweig, Institut für Anorganische und Analytische Chemie, Hagenring 30, 38106 Braunschweig, Germany. mwalter@tu-bs.de.
Dalton Transactions (Cambridge, England : 2003)
|June 21, 2018
Summary
This study details the synthesis and reactivity of novel iron complexes, revealing unique spin state transitions and unexpected transformations during hydrogenation and oxidation reactions. These findings offer new insights into iron chemistry and catalysis.
Area of Science:
- Organometallic Chemistry
- Iron Complexes
- Spin Crossover Phenomena
Background:
- Half-sandwich iron complexes are versatile building blocks in organometallic chemistry.
- Understanding spin state transitions in iron complexes is crucial for catalytic applications.
Purpose of the Study:
- To synthesize and characterize novel iron complexes with varying spin states.
- To investigate the reactivity of these complexes, particularly in hydrogenation and oxidation reactions.
- To explore the influence of spin states on reaction pathways.
Main Methods:
- Synthesis of half-sandwich iron complexes.
- Single-crystal X-ray crystallography for structural determination.
- Mössbauer spectroscopy and magnetic susceptibility measurements for spin state analysis.
- Reactivity studies including hydrogenation and oxidation.
Main Results:
- The complex [Cp'Fe(μ-I)]2 undergoes thermal cleavage to form a cation-anion pair with distinct Fe(II) spin states (low-spin and high-spin).
- Oxidation yields a stable 15-electron Fe(III) species with an intermediate spin state, which reacts with alkylating agents to form an unprecedented Fe(III) bis(alkyl) complex.
- This Fe(III) bis(alkyl) complex undergoes hydrogenation to form iron hydrides, or reacts with benzene to form a η6-arene complex intermediate that dimerizes.
- Oxidation of the dimer leads to C-C bond cleavage.
Conclusions:
- Novel iron complexes exhibiting diverse spin states were synthesized and characterized.
- The reactivity of these complexes is significantly influenced by their electronic configurations and spin states.
- The study highlights new pathways for iron-mediated transformations, including hydrogenation and C-C bond activation.
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