Polycyclic Aromatic Hydrocarbons Containing A Pyrrolopyridazine Core

Area of Science:

• Organic Chemistry
• Materials Science
• Supramolecular Chemistry

Background:

• Polycyclic aromatic azomethine ylides (PAMYs) are valuable precursors for synthesizing nitrogen-containing polycyclic aromatic hydrocarbons (N-PAHs).
• The development of novel N-PAHs with tailored optoelectronic properties is crucial for advanced materials applications.

Purpose of the Study:

• To synthesize and characterize new N-PAHs with a phenyl-substituted pyrrolopyridazine core.
• To investigate the optoelectronic properties and electronic behavior of the synthesized compounds.

Main Methods:

• 1,3-dipolar cycloaddition reaction between PAMY and a diphenylbutynedione derivative.
• Condensation reaction with hydrazine.
• Structural elucidation using NMR, mass spectrometry, and X-ray crystallography.
• Optoelectronic characterization via UV-Vis absorption, fluorescence spectroscopy, and cyclic voltammetry.
• Computational analysis using density functional theory (DFT) and in situ EPR/UV-Vis-NIR spectroelectrochemistry.

Main Results:

• Successful synthesis of novel N-PAHs, PP-1 and PP-2, featuring a phenyl-substituted pyrrolopyridazine core.
• Confirmation of molecular structures through comprehensive spectroscopic and crystallographic analyses.
• Demonstration of push-pull electronic behavior in PP-1 and PP-2 via DFT calculations.
• Detailed insights into the spectroscopic properties and spin distribution of radical cation species of PP-2.

Conclusions:

• This work expands the library of N-PAHs through a novel synthetic route.
• The synthesized compounds exhibit promising optoelectronic characteristics suitable for further materials science exploration.
• The study provides a fundamental understanding of the electronic structure and properties of these new N-PAHs.