Reactivity of [{Cp'Fe(μ-I)}₂] toward 3-phospha- and 3-arsaethynolate

Area of Science:

• Organometallic chemistry
• Inorganic synthesis
• Photochemistry

Background:

• Previous synthesis of iron-phosphorus and iron-arsenic complexes required harsh conditions.
• Understanding the reactivity and bonding of these complexes is crucial for developing new materials and catalytic processes.

Purpose of the Study:

• To develop milder synthetic routes for iron-phosphorus and iron-arsenic complexes.
• To investigate the photochemical and thermal reactivity of these complexes, including CO release and cluster formation.
• To elucidate the electronic structure and bonding of the synthesized complexes using spectroscopic and computational methods.

Main Methods:

• Reaction of [Cp'Fe(μ-I)]2 with [Na(OCP)(1,4-dioxane)x] and K(OCAs) for synthesis.
• UV-light irradiation and thermal treatment for CO elimination studies.
• Spectroscopic characterization (including 57Fe Mössbauer spectroscopy) and computational studies (DFT).

Main Results:

• Mild synthesis of [(Cp'Fe)2(μ-η2:η2-P2)(μ-CO)] and [(Cp'Fe)2(μ-η2:η2-As2)(μ-CO)] at ambient temperature.
• Photochemical CO release from the synthesized complexes yields [(Cp'Fe)2(μ-η2:η2-E2)] (E = P, As).
• Thermal CO elimination from the arsenic complex leads to the formation of a Fe3As6 cluster, [(Cp'Fe)3(As3)2].
• Spectroscopic and computational analyses provide insights into bonding and reaction mechanisms.

Conclusions:

• A new, milder synthetic pathway for iron-phosphorus and iron-arsenic complexes has been established.
• The photochemical and thermal reactivity of these complexes allows for controlled CO release and the formation of novel iron-element clusters.
• The study enhances the understanding of bonding and reaction mechanisms in low-valent iron-pnictogen compounds.