An Iterative Divergent Approach to Conjugated Starburst Borane Dendrimers

Area of Science:

• Organic Chemistry
• Materials Science

Background:

• Conjugated dendrimers are complex macromolecules with unique electronic and photophysical properties.
• Triarylboranes are versatile building blocks in organic synthesis and materials science.

Purpose of the Study:

• To develop a new synthetic strategy for creating conjugated triarylborane dendrimers.
• To investigate the electronic and photophysical properties of these novel dendrimers.

Main Methods:

• A divergent synthetic approach involving iridium-catalyzed C-H borylation, fluorination of boronate esters, and trifluoroborate salt reactions.
• Exploration of a convergent synthetic approach.
• Electrochemical and photophysical characterization of the synthesized dendrimers.

Main Results:

• Successful synthesis of conjugated triarylborane dendrimers up to the 2nd generation using a novel divergent method.
• Most dendrimers exhibited multiple, distinct, and reversible reduction potentials, indicating suitability for molecular accumulators.
• 1st generation dendrimers showed good conjugation; however, conjugation did not improve in the 2nd generation. Molar extinction coefficients increased linearly with triarylborane subunits.

Conclusions:

• The developed synthetic strategy is effective for producing conjugated triarylborane dendrimers.
• These dendrimers hold promise for applications in molecular energy storage and as photonic antennas.
• The linear increase in molar extinction coefficients suggests scalability for photonic applications.