Selective white phosphorus activation and functionalization with inorganic Grignard reagents

Area of Science:

• Organometallic Chemistry
• Main Group Chemistry
• Inorganic Phosphorus Chemistry

Background:

• White phosphorus (P4) is a highly reactive allotrope with limited synthetic utility due to its instability.
• Functionalization of P4 typically requires harsh conditions or specialized reagents, hindering broader applications.
• Development of mild and selective methods for P4 modification is crucial for advancing phosphorus chemistry.

Purpose of the Study:

• To develop novel inorganic Grignard reagents for the targeted functionalization of white phosphorus (P4).
• To synthesize and characterize novel P4-containing complexes stabilized by iron-magnesium frameworks.
• To explore the reactivity of these novel P4 complexes with main group element electrophiles.

Main Methods:

• Synthesis of iron-magnesium complexes featuring beta-diketiminate ligands.
• Reaction of these complexes with white phosphorus (P4) to form P4-bridging ligands.
• Characterization of resulting complexes using spectroscopic and crystallographic techniques.
• Thermolysis and photolysis studies of P4 complexes.
• Reactions of P4 complexes with various main group element electrophiles.

Main Results:

• Successful synthesis of iron-magnesium complexes [(DippBDI)Mg(THF)x Fp] and [(DippBDI)MgFp*] (Fp = CpFe(CO)2, Fp* = Cp*Fe(CO)2).
• Formation of novel butterfly-shaped P4(2-) ligands bridging Fe and Mg centers, stabilized by Mg-P interactions.
• Isolation of rare tetraphosphacyclopentadienolate complexes via thermolysis or photolysis.
• Demonstration of high reactivity of a P4-bridging complex with diverse main group electrophiles.
• Synthesis of stable, mixed-substituted tetraphosphanes and an octaphosphane with a Sn2P8 core.

Conclusions:

• The developed inorganic Grignard reagents provide a selective route for P4 functionalization.
• The synthesized butterfly P4 complexes are stabilized by unique non-covalent interactions.
• These P4 complexes serve as versatile precursors for novel phosphorus-containing compounds, including tetraphosphanes and octaphosphanes.