Preparation of Halogenated Fluorescent Diaminophenazine Building Blocks

Strongly Coupled Phenazine-Porphyrin Dyads: Light-Harvesting Molecular Assemblies with Broad Absorption Coverage

The development of light-harvesting architectures with broad absorption coverage in the visible region continues to be an important research area in the field of artificial photosynthesis. Here, we introduce a new class of ethynyl-linked panchromatic dyads composed of dibenzophenazines coupled ortho and meta to tetrapyrroles with an anchoring group that can be grafted onto metal oxide surfaces. Quantum chemical calculations and photophysical measurements of the synthesized materials reveal that both of the dibenzophenazine dyads absorb broadly from 300 to 636 nm and exhibit absorption bands different from those of the constituent chromophore units. Moreover, the different points of attachment of dibenzophenazines to tetrapyrroles give different absorption profiles which computations suggest result from differences in the planarity of the two dyads. Applicability of the dyads in artificial photosynthesis systems was assessed by their incorporation and characterization of their performance in dye-sensitized solar cells.

An efficient and environmentally sustainable domino protocol for the synthesis of structurally diverse spiroannulated pyrimidophenazines using erbium doped TiO2 nanoparticles as a recyclable and reusable heterogeneous acid catalyst

An efficient and environmentally sustainable domino protocol has been presented for the synthesis of structurally diverse spiroannulated pyrimidophenazines involving a four component reaction of 2-hydroxynaphthalene-1,4-dione, benzene-1,2-diamine, cyclic ketones and amino derivatives in the presence of erbium doped TiO2 nanoparticles as a recyclable and reusable heterogeneous acid catalyst. The present synthetic protocol features mild reaction conditions with operational simplicity, excellent yield with high purity, short reaction time and high atom economy with the use of a recoverable and reusable environmentally sustainable heterogeneous catalyst.

Cu-Catalyzed π-Core Evolution of Benzoxadiazoles with Diaryliodonium Salts for Regioselective Synthesis of Phenazine Scaffolds

The Cu-catalyzed regioselective synthesis of phenazine N-oxides was realized from benzoxadiazoles and diaryliodonium salts. The process was initiated by the electrophilic arylation of benzoxadiazoles with diaryliodonium salts and followed by benzocyclization reactions. The further reduction of N-oxides in situ to phenazine scaffolds and deviation to organic fluorescent materials were readily accomplished.

Ratiometric fluorescence monitoring of cerebral Cu2+ based on coumarin-labeled DNA coupled with the Cu2+-induced oxidation of o-phenylenediamine

A novel ratiometric fluorescence assay for cerebral Cu²⁺ has been developed based on coumarin-labeled single-stranded DNA coupled with the Cu²⁺-induced oxidation of o-phenylenediamine.