An electron-deficient porphyrin tape

Area of Science:

• Organic Chemistry
• Materials Science
• Photochemistry

Background:

• Meso-meso-linked Zn(II)-diporphyrins are known for their unique photophysical properties.
• Improving the chemical stability and solubility of these macrocycles is crucial for practical applications.

Purpose of the Study:

• To synthesize a novel hexakis(pentafluorophenyl)-substituted, meso-meso,β-β,β-β triply linked Zn(II)-diporphyrin.
• To characterize its photophysical properties, chemical stability, and solubility.

Main Methods:

• Acid-catalyzed cross-condensation of tetrapyrroethane and dipyrromethane dicarbinol.
• Oxidation using 2,3-dichloro-5,6-dicyanobenzoquinone (DDQ) and Sc(OTf)3.
• Spectroscopic analysis (absorption, oxidation potentials) and lifetime measurements.

Main Results:

• Successful synthesis of the triply linked Zn(II)-diporphyrin (3).
• Observed red-shifted absorption spectrum and split first oxidation potential.
• Exhibited improved chemical stability due to a lowered HOMO and good solubility.
• Measured a two-photon absorption (TPA) cross-section of 1700 GM and an S(1)-state lifetime of 3.3 ps.

Conclusions:

• The novel triply linked Zn(II)-diporphyrin demonstrates enhanced stability and solubility compared to related compounds.
• Its unique electronic and optical properties, including a significant TPA cross-section, make it a promising candidate for advanced materials.