Synthesis of covalently bonded boron-dipyrromethene-diarylethene for building a stable photosensitizer with photo-controlled reversibility

We report the synthesis and characterization of a photosensitizer containing boron-dipyrromethene and diarylethene. The photosensitizer has photo-controlled reversible photosensitivity and offers potential applications in photochemical catalysis and the degradation of organic pollutants.

BODIPY-Appended 2-(2-Pyridyl)benzimidazole Platinum(II) Catecholates for Mitochondria-Targeted Photocytotoxicity

Platinum(II) complexes of the type [Pt(L)(cat)] (1 and 2), in which H2 cat is catechol and L represents two 2-(2-pyridyl)benzimidazole ligands with 4,4-difluoro-4-bora-3a,4a-diaza-s-indacene (BODIPY) pendants, were synthesized to achieve mitochondria-targeted photocytotoxicity. The complexes showed strong absorptions in the range λ=510-540 nm. Complex 1 exhibited intense emission at λ=525 nm in 1 % DMSO/water solution (fluorescence quantum yield of 0.06). Nanosecond transient absorption spectral features indicated an enhanced population of the triplet excited state in di-iodinated complex 2. The generation of singlet oxygen by complex 2 upon exposure to visible light, as evidenced from experiments with 1,3-diphenylisobenzofuran, is suitable for photodynamic therapy because of the remarkable photosensitizing ability. The complexes resulted in excellent photocytotoxicity in HaCaT cells (half maximal inhibitory concentration IC50 ≈3 μm, λ=400-700 nm, light dose=10 J cm(-2) ), but they remained non-toxic in the dark (IC50 >100 μm). Confocal microscopy images of 1 and Pt estimation from isolated mitochondria showed colocalization of the complexes in the mitochondria. Complex 2 displayed generation of reactive oxygen species induced by visible light, disruption of the mitochondrial membrane potential, and apoptosis.

Exploring the Application of the Negishi Reaction of HaloBODIPYs: Generality, Regioselectivity, and Synthetic Utility in the Development of BODIPY Laser Dyes

The generality of the palladium-catalyzed C-C coupling Negishi reaction when applied to haloBODIPYs is demonstrated on the basis of selected starting BODIPYs, including polyhalogenated and/or asymmetrical systems, and organozinc reagents. This reaction is an interesting synthetic tool in BODIPY chemistry, mainly because it allows a valuable regioselective postfunctionalization of BODIPY chromophores with different functional groups. In this way, functional patterns that are difficult to obtain by other procedures (e.g., asymmetrically functionalized BODIPYs involving halogenated positions) can now be made. The regioselectivity is achieved by controlling the reaction conditions and is based on almost-general reactivity preferences, and the nature of the involved halogens and their positions. This ability is exemplified by the preparation of a series of new BODIPY dyes with unprecedented substitution patterns allowing noticeable lasing properties.

BODIPY Dye, the Most Versatile Fluorophore Ever?

BODIPY laser dyes constitute a fascinating topic of research in modern photochemistry due to the large variety of options its chromophore offers, which is ready available for a multitude of synthetic routes. Indeed, in the literature one can find a huge battery of compounds based on the indacene core. The possibility of modulating the spectroscopic properties or inducing new photophysical processes by the substitution pattern of the BODIPY dyes has boosted the number of scientific and technological applications for these fluorophores. Along the following lines, I will overview the main results achieved in our laboratory with BODIPYs oriented to optoelectronic as well to biophotonic applications, stressing the more relevant photophysical issues to be considered in the design of a tailor-made BODIPY for a certain application and pointing out some of the remaining challenges.

Competitive electron transfer in a novel, broad-band capturing, subphthalocyanine–AzaBODIPY–C60 supramolecular triad

A V-configured SubPc–azaBODIPY–C₆₀ supramolecular triad has been synthesized, and the occurrence of sequential energy and competitive electron transfer leading to charge separated states is demonstrated.

A diiodo-BODIPY postmodified metal–organic framework for efficient heterogeneous organo-photocatalysis

A diiodo-BODIPY postmodified MOF acts as a highly active and recyclable heterogeneous photocatalyst for aerobic CDC and oxidation/[3 + 2]cycloaddition reactions under visible light irradiation.

Indolo-quinoline boron difluoride dyes: synthesis and spectroscopic properties

Novel indolo-quinoline compounds were prepared, and their corresponding BF₂-complexes showed fluorescence with large Stokes shifts.

An easily accessible and recyclable copper nanoparticle catalyst for the solvent-free synthesis of dipyrromethanes and aromatic amines

A facile method to prepare a reusable copper nanocatalyst is reported.

Multifunctional polymer nanoparticles: ultra bright near-infrared fluorescence and strong magnetization and their biological applications

Magnetic fluorescent multifunctional polymer NPs Fe₃O₄/DPPBPA@F-127 and their application in MRI and NIR imaging.

Construction of the carbon–chalcogen (S, Se, Te) bond at the 2,6-positions of BODIPY via Stille cross-coupling reaction

Novel 2-chalcogen- or 2,6-dichalcogen-BODIPY derivatives were synthesized by a Pd-catalyzed C–heteroatom Stille cross-coupling reaction, overcoming the limitations of S_NAr.

BODIPY appended copper(ii) complexes for cellular imaging and singlet oxygen mediated anticancer activity in visible light

BODIPY-appended copper(ii) complexes are for cellular imaging and visible light-induced remarkable PDT activity in HeLa/MCF-7 cells with¹O₂-mediated cellular apoptosis.

Single oxygen generation sensitized by spiro(dipyridinogermole)(dithienogermole)s

Three spiro(dipyridinogermole)(dithienogermole) derivatives (1–3), including newly prepared spiro(dipyridinogermole)[di(2-pyridyl)dithienogermole] (3), were examined as photosensitizers for singlet oxygen (¹O₂) generation in dichloromethane–methanol.

Two-photon excitation nanoparticles for photodynamic therapy

Integration of the two-photon excitation (TPE) technique and nanomaterials to construct TPE nanoparticle-based photosensitizers for PDT is summarized and reviewed.

Complexes trans-Pt(BODIPY)X(PEt3)2: excitation energy-dependent fluorescence and phosphorescence emissions, oxygen sensing and photocatalysis

Complexes trans-Pt(BODIPY)X(PEt₃)₂ exhibit dual fluorescence and phosphorescence emissions, whose intensities are modulated by the anionic ligand X⁻ and the excitation wavelengths. They constitute efficient single-component ³O₂ sensors and photocatalysts for aereal photooxidations with quantum yields near unity.

BODIPY decorated dendrimeric cyclotriphosphazene photosensitizers: synthesis and efficient singlet oxygen generators

BODIPY decorated dendrimeric cyclotriphosphazenes were synthesized. The singlet oxygen generation capabilities of them were evaluated. They are proposed as potential photosensitizers that can be used as efficient singlet oxygen generators.

BODIPY catalyzed amide synthesis promoted by BHT and air under visible light

A novel and efficient protocol for the synthesis of amides is reported via a BODIPY catalyzed oxidative amidation of aromatic aldehydes under visible light, with broad substrate scope and mild reaction conditions. Mechanistic studies reveal that dioxygen could be activated through both an ET and SET pathway to form the active peroxide intermediates.