Curved Nanographene Featuring Two sp³ Stereocenters via Oxidative Cyclodehydrogenation with Aryl Rearrangement

Area of Science:

• Organic Chemistry
• Materials Science
• Nanotechnology

Background:

• Development of novel polycyclic aromatic hydrocarbons (PAHs) with unique structural and electronic properties.
• Exploration of sp³-hybridized carbons in PAHs to induce three-dimensionality and chirality.
• Significance of curved nanographenes in advanced materials and molecular electronics.

Purpose of the Study:

• To synthesize a novel curved nanographene featuring sp³ stereocenters.
• To investigate the structural consequences of incorporating sp³ carbons into a nanographene framework.
• To assess the chirality and configurational stability of the synthesized molecule.

Main Methods:

• Synthesis via Scholl-type oxidative cyclodehydrogenation with an observed aryl rearrangement.
• Structural characterization using single-crystal X-ray diffraction.
• Chiral resolution of enantiomers and circular dichroism spectroscopy.

Main Results:

• Successful synthesis of curved nanographene 1 containing two sp³ stereocenters.
• X-ray diffraction confirmed significant distortion and orthogonal arrangement of aromatic sheets due to sp³ carbons.
• Demonstrated inherent chirality and high configurational stability of nanographene 1.
• Resolved enantiomers exhibited distinct mirror-image circular dichroism spectra.

Conclusions:

• The incorporation of sp³ stereocenters effectively induces significant curvature and chirality in nanographenes.
• The synthesized molecule possesses remarkable configurational stability, making it a promising candidate for chiral applications.
• Circular dichroism spectroscopy confirms the enantiomeric nature and optical activity of the resolved compounds.