Beta-octafluorocorroles.

Area of Science:

• Synthetic organic chemistry
• Coordination chemistry
• Materials science

Background:

• The one-pot synthesis of corroles has evolved into a general self-assembly reaction.
• Previous work established the reaction's applicability with various aromatic aldehydes.
• The pyrrole component's variability in corrole synthesis was not fully explored.

Purpose of the Study:

• To investigate the variability of the pyrrole component in corrole synthesis.
• To synthesize and characterize novel beta-octafluorinated triarylcorroles and their metal complexes.
• To evaluate the electronic properties and noninnocent ligand behavior of these fluorinated corroles.

Main Methods:

• Oxidative condensation of 3,4-difluoropyrrole with various p-X-substituted benzaldehydes.
• Preparation of copper (Cu) and iron (FeCl) complexes of the beta-octafluorocorrole ligands.
• Characterization using X-ray photoelectron spectroscopy (XPS), NMR spectroscopy (1H, 19F), and DFT calculations.

Main Results:

• Successful synthesis of four beta-octafluorinated triarylcorroles and their Cu and FeCl complexes.
• Fluorinated ligands exhibit higher ionization potentials and positively shifted oxidation potentials, indicating electron deficiency.
• FeCl complexes display less pi-cation radical character compared to their non-fluorinated counterparts.
• Cu complexes show a thermally accessible paramagnetic excited state, assigned as Cu(II) corrole pi-cation radical.
• Soret absorption maxima of free-base fluorinated corroles are insensitive to meso-substituents, while Cu complexes show a ~35 nm red-shift from p-CF3 to p-OCH3.

Conclusions:

• The pyrrole component in corrole synthesis is highly variable, enabling access to novel fluorinated analogues.
• Beta-octafluorinated triarylcorroles are strongly electron-deficient ligands with tunable electronic properties.
• The electronic and magnetic properties of metal-corrole complexes are influenced by fluorine substitution and metal center.