Carbene-stabilized diphosphorus: bidentate complexation of BH2(+)

Area of Science:

• Organophosphorus Chemistry
• Boron Chemistry
• Supramolecular Chemistry

Background:

• Carbene-stabilized diphosphorus compounds represent a unique class of low-valent phosphorus species.
• Borane adducts are crucial reagents in synthetic chemistry, particularly for hydroboration and reduction reactions.
• The exploration of novel ring systems involving phosphorus and boron is an active area of research.

Purpose of the Study:

• To investigate the reactivity of carbene-stabilized diphosphorus (1) with borane.
• To synthesize and characterize new phosphorus-boron containing compounds.
• To study the solution behavior and stability of the resulting products.

Main Methods:

• Reaction of L:P-P:L (1) with excess BH(3)·THF.
• Isolation and characterization of the boronium salt [L:P(μ-BH(2))P:L](+)[B(2)H(7)](-) (2) using spectroscopic techniques.
• Investigation of the solution equilibrium between compounds 1 and 2 in THF.

Main Results:

• The reaction yielded the boronium salt 2, featuring an unprecedented three-membered P(2)B ring.
• Compound 2 was characterized, confirming the presence of the novel ring structure.
• A dynamic solution equilibrium was observed between the diphosphorus compound 1 and the boronium salt 2 in THF.

Conclusions:

• Carbene-stabilized diphosphorus compounds readily react with borane to form unique P-B ring systems.
• The P(2)B ring system is stable in the solid state but exhibits dynamic behavior in solution.
• This study expands the scope of phosphorus-boron chemistry and highlights the versatility of diphosphorus reagents.