Boron-doped tri(9,10-anthrylene)s: synthesis, structural characterization, and optoelectronic properties

Area of Science:

• Organometallic Chemistry
• Materials Science
• Photophysics

Background:

• 9,10-Dibromo-9,10-dihydro-9,10-diboraanthracene (DBA) serves as a versatile precursor for novel organoboron compounds.
• Steric interactions and electronic effects of substituents on DBA derivatives influence their structural and photophysical properties.

Purpose of the Study:

• To synthesize and characterize new 9,10-dianthryl-DBA derivatives with varying tert-butyl group arrangements and functional substituents.
• To investigate the impact of molecular structure on the electronic, optical, and photophysical properties of these DBA compounds.

Main Methods:

• Synthesis of 9,10-dianthryl-DBA derivatives via reactions of 9,10-dibromo-DBA with lithiated di-tert-butylanthracenes.
• Structural characterization using X-ray crystallography and solution-state NMR spectroscopy.
• Electrochemical analysis via cyclic voltammetry and photophysical studies including UV-Vis absorption and emission spectroscopy.

Main Results:

• Novel DBA derivatives with inward- or outward-pointing tert-butyl groups were successfully synthesized and isolated.
• X-ray crystallography revealed twisted conformations and attractive interactions between tert-butyl groups in some derivatives.
• Compounds exhibited tunable electronic properties, including reversible redox waves and significant intramolecular charge-transfer (ICT) characteristics, leading to broad absorption and solvatochromic emission.

Conclusions:

• The steric arrangement of tert-butyl groups and the electronic nature of substituents significantly impact the conformation and photophysics of 9,10-dianthryl-DBA compounds.
• These novel DBA derivatives demonstrate potential as functional materials for optoelectronic applications due to their ICT properties and tunable emission.
• The study highlights the rational design of organoboron compounds with tailored structural and electronic features.