Isocyanide Substituent Influences Reductive Elimination versus Migratory Insertion in Reaction with an [Fe₂(μ-H)₂]²⁺...

Area of Science:

• Organometallic Chemistry
• Catalysis
• Inorganic Chemistry

Background:

• Iron hydrides are crucial intermediates in N₂ and CO conversion relevant to industrial and biological processes.
• Understanding the reactivity of iron hydrides with small molecules is vital for developing new catalytic systems.

Purpose of the Study:

• To investigate the reactivity of a low-coordinate di(μ-hydrido)diiron(II) complex with various isocyanides.
• To elucidate the influence of isocyanide substituents on the reaction outcome and product formation.

Main Methods:

• Synthesis and characterization of a di(μ-hydrido)diiron(II) complex featuring a bis(β-diketiminate) cyclophane ligand.
• Reaction of the iron hydride complex with a series of isocyanides (2,6-xylyl, tert-butyl, isopropyl, methyl).
• Spectroscopic and structural analysis of the resulting iron complexes and organic products.

Main Results:

• The reaction outcome is highly dependent on the isocyanide substituent.
• 2,6-xylyl isocyanide promotes H₂ loss, forming a bis(μ-1,1-isocyanide)diiron(I) complex.
• Other isocyanides undergo insertion into the Fe-H bond, yielding (μ-1,2-iminoformyl) complexes, with the extent of insertion controlled by steric bulk.

Conclusions:

• The steric and electronic properties of isocyanides significantly influence the reactivity of di(μ-hydrido)diiron(II) complexes.
• This study provides insights into controlling reaction pathways for N₂ and CO surrogates using iron hydride complexes.
• The findings contribute to the development of novel iron-based catalysts for small molecule transformations.