Phosphetene-Based Polyaromatics: Structure-Property Relationships and Chiroptical Tuning

Area of Science:

• Organic Chemistry
• Materials Science
• Photophysics

Background:

• Phosphetene rings (4-member P-rings) are strained heterocyclic compounds with unique electronic properties.
• Polycyclic Aromatic Hydrocarbons (PAHs) are known for their optical and electronic characteristics.
• Chiroptical properties, particularly circularly polarized luminescence (CPL), are of interest for advanced optical applications.

Purpose of the Study:

• To synthesize and characterize novel π-extended phosphetene-PAH conjugates.
• To investigate the influence of phosphetene rings and PAH topology on structural, optical, and redox properties.
• To explore the potential of stereogenic phosphorus atoms in phosphetene rings for inducing chiroptical properties in PAHs.

Main Methods:

• Synthesis of π-extended phosphetene-PAH systems.
• Full characterization including X-ray diffraction analysis.
• Experimental and theoretical investigations of optical and redox properties.
• Computational studies (e.g., DFT) to understand electronic structure and chiroptical behavior.

Main Results:

• Successful synthesis of π-extended phosphetene-PAH compounds with diverse PAH topologies.
• X-ray diffraction confirmed the molecular structures.
• Phosphetene units and PAH platforms modulate structural symmetry and electronic properties.
• The stereogenic phosphorus atom acts as a remote chiral inducer, leading to circularly polarized luminescence (CPL).
• The dissymmetry factor of CPL is significantly influenced by the PAH topology.

Conclusions:

• Novel π-extended phosphetene-PAH systems offer a platform for designing chiral optoelectronic materials.
• The stereogenic phosphorus center provides an effective strategy for remote induction of CPL in PAH chromophores.
• PAH topology plays a crucial role in tuning the chiroptical response, enabling tailored CPL emission.