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Preparation of a Corannulene-functionalized Hexahelicene by CopperI-catalyzed Alkyne-azide Cycloaddition of Nonplanar Polyaromatic Units
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Aromaticity of biphenylene networks
Lenara I Valiulina1, R Valiyev2, Victor N Cherepanov1
1Tomsk State University, 36 Lenin Avenue, Tomsk, 634050, Russia. valiulina.lenara.01.01.1998@gmail.com.
Physical Chemistry Chemical Physics : PCCP
|October 1, 2024
Summary
Biphenylene sheets and nanoribbons exhibit antiaromaticity due to strong paratropic ring currents. Halogen substitution slightly reduces current strength, enhancing diamagnetic properties, with BHandHLYP recommended for accurate magnetic susceptibility calculations.
Area of Science:
- Computational chemistry
- Materials science
- Organic electronics
Background:
- Biphenylene systems are novel carbon allotropes with unique electronic properties.
- Understanding magnetic responses is crucial for designing advanced materials.
Purpose of the Study:
- To investigate magnetically induced ring currents and magnetic susceptibilities in biphenylene sheets and nanoribbons.
- To explore the impact of edge structure (armchair, zigzag) and functionalization (H, Br, F) on magnetic properties.
Main Methods:
- Density Functional Theory (DFT) calculations were employed.
- Analysis of paratropic and diatropic ring currents.
- Comparison of B3LYP and BHandHLYP functionals for magnetic property prediction.
Main Results:
- Biphenylene structures display dominant paratropic ring currents, indicating antiaromatic character.
- Electron delocalization primarily occurs along the edges, through cyclobutadiene units.
- Halogenation (Br, F) slightly decreases ring current strength and enhances diamagnetism.
Conclusions:
- Biphenylene networks possess inherent antiaromaticity driven by edge currents.
- Functionalization offers a route to tune magnetic properties.
- The BHandHLYP functional is more reliable for calculating magnetic susceptibility in these systems.
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