Stepwise Reduction of 9,10-Bis(dimesitylboryl)anthracene

Area of Science:

• Organic Chemistry
• Materials Science
• Computational Chemistry

Background:

• Anthracene derivatives are key components in organic electronics.
• Understanding redox-induced structural changes is crucial for designing new materials.
• Borylated organic molecules offer unique electronic properties.

Purpose of the Study:

• To investigate the structural and electronic consequences of stepwise reduction in 9,10-bis(dimesitylboryl)anthracene.
• To correlate changes in aromaticity with molecular geometry upon electron addition.
• To elucidate the bonding principles governing these transformations.

Main Methods:

• Electrochemical reduction studies using cyclic voltammetry.
• Structural characterization via X-ray crystallography.
• Spectroscopic analysis including NMR, EPR, and UV-vis-NIR.
• Theoretical validation through Density Functional Theory (DFT) calculations.

Main Results:

• Stepwise reduction yielded a radical anion and a dianion.
• The radical anion exhibited a planar semiquinoidal structure.
• The dianion displayed a puckered quinoidal structure, indicating significant changes in anthracene aromaticity.
• Experimental and computational data confirmed the observed geometric alterations and their dependence on bonding.

Conclusions:

• The electronic structure and bonding in 9,10-bis(dimesitylboryl)anthracene dictate its geometry upon reduction.
• Reduction leads to a transition from aromatic to quinoidal structures.
• This study provides fundamental insights into the redox behavior and structural dynamics of borylated polycyclic aromatic hydrocarbons.