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B-N-B Bond Embedded Phenalenyl and Its Anions
Haipeng Wei1, Yulan Liu1, Tullimilli Y Gopalakrishna2
1State Key Laboratory of Chemo/Biosensing and Chemometrics, College of Chemistry and Chemical Engineering, Hunan University , Changsha 410082, People's Republic of China.
Journal of the American Chemical Society
|October 14, 2017
Summary
This study introduces novel boron-nitrogen-boron (B-N-B) embedded phenalenyls and their anionic forms. These compounds exhibit unique electronic structures and reactivity, expanding possibilities in organic optoelectronics.
Area of Science:
- Organic Chemistry
- Materials Science
- Supramolecular Chemistry
Background:
- Heteroatom-containing polycyclic aromatic hydrocarbons (PAHs) show promise in organic optoelectronics.
- Limited research exists on heteroaromatics featuring a boron-nitrogen-boron (B-N-B) bond within their π-scaffold.
Purpose of the Study:
- To synthesize and characterize novel 1,9-dibora-9a-azaphenalenyl (DBAP) derivatives, referred to as BNB-embedded phenalenyls.
- To investigate the electronic structure and reactivity of these new compounds and their anionic species.
- To explore the isoelectronic relationships between DBAP derivatives and phenalenyl cations, anions, and radicals.
Main Methods:
- Chemical reduction of DBAP derivatives using potassium.
- X-ray crystallographic analysis to determine molecular structures.
- Theoretical calculations to understand electronic properties and delocalization.
- Spectroscopic analysis for characterization.
Main Results:
- Stable BNB-embedded phenalenyl derivatives (DBAP) were synthesized.
- Chemical reduction yielded a dianion (14 π-electrons) isoelectronic to the phenalenyl anion.
- An unusual rearrangement produced a BNB-embedded benzo[cd]fluoranthene dianion (20 π-electrons) from the monoanion, confirmed by X-ray crystallography.
- The B-N-B moiety participates in π-electron delocalization, albeit with more localized character compared to all-carbon analogues.
Conclusions:
- This work reports the first synthesis and characterization of BNB-embedded phenalenyls and their anionic species.
- These compounds exhibit unique electronic structures and reactivity distinct from traditional phenalenyls.
- The findings open new avenues for designing advanced materials for organic optoelectronics.
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