Near-IR absorbing J-aggregates of a phenanthrene-fused BODIPY as a highly efficient photothermal nanoagent.

A phenanthrene-[b]-fused BODIPY exhibited well-defined J-aggregation behavior in both pure hydrocarbon solution and aqueous solution. The highly stable J-aggregates showed narrowed and largely red-shifted absorption with λmax of 840 nm and enhanced molar absorption coefficients (271 000 M-1 cm-1). Encapsulation of J-aggregates within a micellar nanocapsule resulted in nanoparticles that demonstrated good biocompatibility, excellent photothermal stability, high photothermal conversion ability (η ∼ 46.9%) and an effective phototoxicity (IC50 ∼ 2 µg mL-1 in HeLa cells) under 808 nm laser irradiation.

Distribution of N-nitrosamines in drinking water and human urinary excretions in high incidence area of esophageal cancer in Huai'an, China.

The Huai'an area in Jiangsu Province of East China is an endemic region of esophageal cancer (EC). The regional heterogeneity of EC suggests that the levels of potential carcinogens might vary throughout the environment. It has been suggested that the most likely carcinogens related to EC are a group known as the N-nitrosamines. In this study, we measured the concentrations of nine nitrosamines in drinking water and human urine in two areas in China, one with a high incidence of EC (Huai'an) and one with a low incidence (Nanjing). Among the nine target analytes, N-nitrosodi-n-propylamine (NDPA), N-nitrosodibutylamine (NDBA), N-nitrosopyrrolidine (NPyr), N-nitrosodiethylamine (NDEA) and N-nitrosomorpholine (NMor) occurred at higher concentrations in drinking water in the high incidence area. Inhabitants from the high incidence area also had urinary excretions with significantly higher concentrations of NDEA, NDBA, N-nitrosopiperidine (NPip) and N-nitrosodiphenylamine (NDPhA). These findings indicated that people in the high EC incidence area were exposed to higher levels of nitrosamines. However, the association between the incidence of EC and nitrosamines exposure will need to be evaluated in more detail.

Phenanthro[b]-Fused BODIPYs through Tandem Suzuki and Oxidative Aromatic Couplings: Synthesis and Photophysical Properties.

A new synthetic method to build phenanthrene-fused boron dipyrromethenes (BODIPYs) through tandem Suzuki couplings on readily available 2,3,5,6-tetrabromoBODIPYs, followed by an intramolecular oxidative aromatic coupling mediated by iron(III) chloride is reported. This efficient synthesis allows a very straightforward approach for tuning the absorption and emission of BODIPYs in the red/near-infrared (NIR) range. These resulting phenanthrene-fused BODIPYs exhibit strong absorption (extinction coefficients up to 2.2 × 105 M-1 cm-1) and emission in the near-infrared (NIR) range (688-754 nm). Substituents on the resulting phenanthrene rings have a significant impact on the photophysical properties of these phenanthrene-fused BODIPYs.

Regioselective and Stepwise Syntheses of Functionalized BODIPY Dyes through Palladium-Catalyzed Cross-Coupling Reactions and Direct C-H Arylations.

Regioselective and stepwise syntheses of a series of functionalized BODIPY dyes through palladium-catalyzed cross-coupling reactions and direct C-H arylations have been developed. In particular, this method allows the straightforward synthesis of 2,6-dibromo-3,5-diarylBODIPYs and 2-bromo-3-arylBODIPYs from polybrominated BODIPYs. The X-ray structure of intermediates 5a-c indicated that the palladium was first inserted into the C-Br bonds at 3,5-positions of brominated BODIPYs. The resulting 2,6-dibromo-substituted BODIPYs are potential long wavelength photosensitizers which are not easily accessible using previous methods.

Tandem Regioselective Substitution and Palladium-Catalyzed Ring Fusion Reaction for Core-Expanded Boron Dipyrromethenes with Red-Shifted Absorption and Intense Fluorescence.

A selective method for the core-extension of boron dipyrromethene (BODIPY) with two annulated indole rings with exclusive syn-connectivity is reported. The method is based on a regioselective nucleophilic substitution reaction of 2,3,5,6-tetrabromoBODIPY with aryl amines, followed by palladium-catalyzed intramolecular C-C coupling ring fusion. The unsymmetrical core-expanded BODIPY with annulated indole and benzofuran rings was also synthesized by stepwise and regioselective nucleophilic substitution and palladium-catalyzed intramolecular C-C coupling reaction. The diindole-annulated BODIPY was unambiguously characterized by single-crystal X-ray analysis. The optical properties of the present core-expanded BODIPYs were studied, revealing clearly red-shifted absorption and emission bands and enhanced absorption coefficients upon annulation.