A benzofuran-[]-fused BODIPY trimer enabled by dual TBET and PET mechanisms for high-performance two-photon fluorescence imaging.

A benzofuran-[]-fused BODIPY trimer has been efficiently synthesized, featuring a unique structural design that harmoniously integrates TBET (through bond energy transfer) and PET (photo-induced electron transfer) mechanisms. This trimer boasts exceptional optical properties, including a large pseudo-Stokes shift of 100 nm, an impressive fluorescence quantum yield ( = 0.931), an outstandingly high extinction coefficient (182 100 M cm), a remarkable FEF (fluorescence enhancement factors, 22.

Tuning Shortwave-Infrared J-aggregates of Aromatic Ring-Fused Aza-BODIPYs by Peripheral Substituents for Combined Photothermal and Photodynamic Therapies at Ultralow Laser Power.

Achieving photothermal therapy (PTT) at ultralow laser power density is crucial for minimizing photo-damage and allowing for higher maximum permissible skin exposure. However, this requires photothermal agents to possess not just superior photothermal conversion efficiency (PCE), but also exceptional near-infrared (NIR) absorptivity. J-aggregates, exhibit a significant redshift and narrower absorption peak with a higher extinction coefficient.

Tuning of Redox Potentials and LUMO Levels of BODIPYs via Site-Selective Direct Cyanation.

Through a strong oxidant Pb(OAc) promoted oxidative nucleophilic hydrogen substitution, site-selective direct and stepwise cyanation of BODIPYs using tetrabutylammonium cyanide was developed to give α-cyanated BODIPY derivatives. Characterization of optical and electrochemical properties of these dyes provides substantial enhancement of the electron affinity, with a reduction potential and LUMO level as low as -0.04 V and -4.

Regioselective Synthesis of Directly Connected BODIPY Dimers through Oxidative Coupling of α-Amino-Substituted BODIPYs.

A family of directly β,β-linked BODIPY dimers with amino groups at α-positions were regioselectively prepared by the oxidative coupling reaction of α-amino-substituted BODIPYs. The structure of one representative dimer was elucidated by X-ray diffraction analysis, showing its twisted orientation of two BODIPY units with a dihedral angle of 49°. Comparing with the corresponding monomers, these dimers showed red-shifted absorptions and emissions along with efficient intersystem crossing, giving Φ of 43% for dimer in toluene, indicating potential use as heavy-atom-free photosensitizers.