Charge localization and charge transfer in the Bebq2 monomer and dimer

Area of Science:

• Computational chemistry
• Materials science
• Quantum mechanics

Background:

• Bis(10-hydroxybenzo[h]quinolinato)beryllium (Bebq2) is a molecule with potential applications in organic electronics.
• Understanding the electronic and structural properties of Bebq2 in different charge states is crucial for device optimization.

Purpose of the Study:

• To investigate the geometrical structure and electronic properties of Bebq2 molecules and dimers.
• To analyze the behavior of Bebq2 in neutral, positively charged, and negatively charged states.
• To elucidate the mechanisms of charge localization and transfer in Bebq2 systems.

Main Methods:

• Quantum-chemical calculations were employed to study Bebq2.
• The study considered both monomeric and dimeric forms of Bebq2.
• Calculations were performed for neutral and charged (positive and negative) states.

Main Results:

• Excess charge in charged Bebq2 systems localizes on a single hydroxybenzoquinoline ligand.
• Significant structural modifications are observed in the charged ligand, while the neutral ligand remains largely unchanged.
• Charge transfer can occur within a single Bebq2 monomer or between monomers in a Bebq2 dimer.

Conclusions:

• The localization of charge and differential structural changes in Bebq2 are key factors governing its electronic behavior.
• The study provides insights into charge transfer pathways, essential for designing organic electronic materials.
• Hopping integrals were estimated, offering quantitative data for charge transport phenomena in Bebq2-based systems.