π-Extended indenofluorenes

Area of Science:

• Organic Chemistry
• Materials Science
• Photophysics

Background:

• Indenofluorene (IF) derivatives are important organic semiconductors.
• Extending π-conjugation is a common strategy to tune optoelectronic properties.

Purpose of the Study:

• To synthesize novel π-extended indenofluorene analogues with naphthalene and anthracene cores.
• To investigate the effect of ring connectivity on the optoelectronic properties of these new compounds.

Main Methods:

• Acid-catalyzed intramolecular cyclization for synthesis.
• Density Functional Theory (DFT) calculations.
• Absorption and emission spectroscopy.
• Cyclic voltammetry and spectroelectrochemical studies.

Main Results:

• Successful synthesis of indenofluorene analogues with extended aromatic cores.
• Regioselectivity influenced by steric and electronic factors, yielding multiple regioisomers.
• All regioisomers showed redshifted absorption/emission compared to parent IF analogues.
• Optoelectronic properties, including luminescence quantum yield, showed complex dependence on ring connectivity.

Conclusions:

• The study successfully synthesized novel π-extended indenofluorenes.
• Ring connectivity significantly influences optoelectronic properties, but not always in a straightforward manner.
• These findings contribute to the rational design of organic electronic materials.