A Phosphorus(V)-Centered Porphyrin Having Redox- and Air-Stable Axial P-H Bonds

Area of Science:

• Organometallic Chemistry
• Materials Science
• Supramolecular Chemistry

Background:

• Phosphorus(V)-porphyrins (P(V)-porphyrins) are versatile functional dyes.
• Axial ligands on the phosphorus atom tune electronic properties and introduce new functionalities.
• Exploring novel axial ligands is crucial for advancing P(V)-porphyrin applications.

Purpose of the Study:

• To synthesize and characterize a new P(V)-porphyrin featuring hydrogen atoms as axial ligands.
• To investigate the structural, electronic, and redox properties of the synthesized compound.
• To assess the stability and potential applications of this novel P(V)-porphyrin.

Main Methods:

• Synthesis of the target P(V)-porphyrin (1⁺·PF₆ ^-) from a dichloro-derivative (2⁺·Cl^-) using hydride reduction.
• Characterization using spectroscopic techniques and X-ray crystallography (implied by structural description).
• Electrochemical analysis via cyclic voltammetry to determine redox behavior.

Main Results:

• Successful synthesis and characterization of a novel P(V)-porphyrin with P-H axial bonds (1⁺·PF₆ ^-).
• The porphyrin core exhibits a nonplanar, ruffled structure.
• Cyclic voltammetry reveals two reversible redox waves, indicating stable redox couples (1⁺/1^•/1^-).

Conclusions:

• The synthesized P(V)-porphyrin with hydrogen axial ligands demonstrates unique electronic and redox characteristics.
• Despite the presence of P-H bonds, the compound exhibits air tolerance due to a low-lying HOMO.
• This discovery opens new avenues for designing functional P(V)-porphyrins with tunable properties.