Phosphorus-Bismuth Peri-Substituted Acenaphthenes: A Synthetic, Structural, and Computational Study

Area of Science:

• Organometallic Chemistry
• Main Group Chemistry
• Inorganic Synthesis

Background:

• Acenaphthene derivatives are versatile scaffolds in synthetic chemistry.
• Interpnictogen bonds, particularly P-Bi bonds, are relatively uncommon.
• Understanding bonding and electronic communication in novel organometallic compounds is crucial.

Purpose of the Study:

• To synthesize and characterize novel acenaphthene species containing phosphorus and bismuth.
• To investigate the formation and properties of the rare interpnictogen P-Bi bond.
• To explore the electronic communication through space in geminally substituted compounds.

Main Methods:

• Synthesis of acenaphthene derivatives with diisopropylphosphino and bismuth functionalities.
• Full characterization including single-crystal X-ray diffraction.
• Fluorodearylation reactions to introduce various bismuth functionalities.
• Nuclear magnetic resonance (NMR) spectroscopy to study coupling phenomena.
• Coupling deformation density calculations to analyze bonding pathways.

Main Results:

• Successful synthesis of acenaphthene species with P-Bi bonds.
• Formation of Acenap(PiPr₂)(BiPh₂) and its derivatives Acenap(PiPr₂)(BiPhX) with varying ionicity.
• Observation of a significant through-space P-P coupling (^8TSJ_PP) in [Acenap(PiPr₂)]₂BiPh, explained by lone pair mediation.
• Investigation into synthetic routes for Acenap(PiPr₂)(BiI₂) yielding a thermally stable but impure product.

Conclusions:

• The study demonstrates the accessibility of acenaphthene-based compounds featuring P-Bi bonds.
• The observed through-space coupling highlights novel electronic communication mechanisms mediated by lone pairs.
• These findings contribute to the understanding of bonding in P-Bi systems and offer potential for further synthetic exploration.