Redox Chemistry of BODIPY Dyes

Abstract

The implementation of BODIPY dyes in electron transfer reactions is an exciting new frontier that expands the toolbox of the dye molecule that has primarily been implemented in biological and chemical sensing applications. BODIPY dyes are capable of reversible reductions at the average reduction potential of −1.53 V vs. ferrocene/ferrocenium, varying about 700 mV from this average value depending on the substitution of the BODIPY core. BODIPY dyes are also capable of reversible oxidations, exhibiting an average oxidation potential of 610 mV with the ability to manipulate the oxidation potential up to 600 mV from the average potential. The respective azaBODIPY dyes are on average about 600 mV easier to reduce (more positive potentials) and are oxidized at almost identical oxidation potentials to the respective BODIPY dyes. The oxidation and reduction potentials of BODIPY dyes are heavily dependent on substitution of the BODIPY core, which allows for a high degree of tunability in the redox potentials. This characteristic makes BODIPY dye molecules good candidates for use as photoredox catalysts, redox flow batteries, redox-active ligands, light harvesting antenna, and many other applications in materials science, biology, and chemical synthesis.

Heavy-atom-free BODIPY photosensitizers with intersystem crossing mediated by intramolecular photoinduced electron transfer

“…Introduction of a single methyl group in the BODIPY core can decrease the reduction potential by up to 100-150 mV, depending on the substitution position. 86 Increasing the number of alkyl substituents in pyrrolic rings results in more facile oxidation of the BODIPY. This can be employed for promoting electron transfer from the BODIPY subunit to the electron-accepting aryls, as seen from the results obtained with dyads 14-24.…”

Catalyst Halogenation Enables Rapid and Efficient Polymerizations with Visible to Far-Red Light

“…A series of boron-dipyrromethene (BODIPY) dyes were selected to address these photopolymerization challenges. In spite of the attractive traits of BODIPYs, including tunable optoelectronic properties, high molar extinction, and facile and modular syntheses, − they have received far less attention as photopolymer catalysts ,, in comparison to their xanthene and cyanine counterparts (Scheme ). However, the BODIPY platform has been heavily examined for imaging, , sensing, and photodynamic therapy , applications.…”

Quantum Chemical Study Aimed at Modeling Efficient Aza-BODIPY NIR Dyes: Molecular and Electronic Structure, Absorption, and Emission Spectra

“…Moreover, the dihedral angle for the 2-thiophenyl and 2-furanyl groups is smaller than for other groups; it can also lead to π-delocalization. It is known that the aza-BODIPY is seen to exhibit less aromatic character than the BODIPY [ 34 ].…”