Electron-deficient P(v) corroles as dual-functional materials for selective fluoride detection and photocatalysis

Abstract

Phosphorus(V) corroles incorporating electron-withdrawing groups and π-extended meso-aryl fluorophoric substituents (P1 and P2) were synthesized and characterized using various basic spectroscopic methods including ¹H NMR, ³¹P NMR, and ESI mass spectrometry. The P(V) corroles demonstrated selective fluoride ion (F⁻) sensing by distinct colorimetric and fluorometric changes among a series of anions, with detection limits of 0.39 μM for P1 and 0.34 μM for P2. Spectroscopic techniques including FT-IR and ESI mass spectrometry, along with electrochemical measurements, established a 1 : 1 binding stoichiometry between the corrole and F⁻ through hydrogen bonding interactions. Computational studies (DFT and TD-DFT) supported the experimental observations. The practical application of these sensors was established through solid-state detection and smartphone-assisted RGB analysis. Furthermore, P1 and P2 functioned as effective photocatalysts for the aerobic oxidation of sulfides to sulfoxides using molecular oxygen as the sole oxidant. Mechanistic investigations revealed the involvement of molecular oxygen in the photocatalytic cycle. These findings highlight the dual functions of P(V) corroles as both sensitive F⁻ probes and efficient photocatalysts.